Essential Biochemistry, 3rd Edition Pratt, Cornely Test Bank.pdf

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Test Bank

Resource:

Essential Biochemistry

Edition: Author(s):

3rd Edition Charlotte W. Pratt Kathleen Cornely

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 1 Question type: Multiple Choice 1) Which of the following is the most abundant element in the human body?

A) B) C) D) E)

nitrogen carbon oxygen phosphorous none of the above

Answer: B Difficulty: Easy Section Reference: 1-2 Learning Objective: Distinguish the four main types of biological molecules and their polymers 2) Of the following amino acids, which contains an alcohol? a

b

c

d

A) a B) b C) c D) d E) all of the above Answer: A Difficulty: Easy Section Reference: 1-2 Learning Objective: Distinguish the four main types of biological molecules and their polymers

3) Which of the major types of biomolecules is never found in a polymeric form?

A) amino acids B) carbohydrates C) nucleotides D) lipids E) none of the above Answer: D Difficulty: Medium Section Reference: 1-2 Learning Objective: Distinguish the four main types of biological molecules and their polymers

4) Which of the following biopolymers is correctly paired with the bond that forms between the monomers?

A) protein: ester bond B) polysaccharide: glycosidic bond C) DNA: phosphate bond D) RNA: phosphate bond E) all of the above Answer: B Difficulty: 3 Section Reference: 1-2 Learning Objective: Distinguish the four main types of biological molecules and their polymers

5) Which of the biopolymers is correctly paired with its major function?

A) protein: information encoding B) nucleic acids: energy storage C) lipids: information encoding D) polysaccharide: energy storage E) none of the above Answer: D Difficulty: Medium Section Reference: 1-2 Learning Objective: Distinguish the four main types of biological molecules and their polymers 6) What functional groups are present in the following molecule?

A) amine and carboxylic acid B) amine, ketone and carboxylic acid C) amine, amide and carboxylic acid D) alcohol, amine, amide and carboxylic acid E) none of the above are correct Answer: C Difficulty: Medium Section Reference: 1-2 Learning Objective: Distinguish the four main types of biological molecules and their polymers 7) Which elements are found in simple carbohydrates?

A) carbon, hydrogen and oxygen B) carbon, hydrogen, oxygen and nitrogen C) carbon, hydrogen, oxygen and phosphorous D) carbon, hydrogen, oxygen and sulfur E) none of the above Answer: A Difficulty: Medium Section Reference: 1-2 Learning Objective: Distinguish the four main types of biological molecules and their polymers 8) Entropy is used to measure _____.

A) free energy B) heat content C) temperature D) randomness E) all of the above Answer: D Difficulty: Easy

Section Reference: 1-3 Learning Objective: Explain how enthalpy, entropy, and free energy apply to biological systems 9) A spontaneous process always has _____.

A) G < 0 B) G > 0 C) H < 0 D) H > 0

E) none of the above Answer: A Difficulty: Easy Section Reference: 1-3 Learning Objective: Explain how enthalpy, entropy, and free energy apply to biological systems

10) If a reaction at 37C has a H of 23 kJ/mol and a S of 337 J/K•mol, what is the G for the reaction?

A) 65 kJ/mol B) -42 kJ/mol C) 18 kJ/mol D) -19 kJ/mol E) none of the above Answer: D Difficulty: Hard Section Reference: 1-3 Learning Objective: Explain how enthalpy, entropy, and free energy apply to biological systems

11) An exergonic process _____.

A) occurs without the addition of free energy

B) has a G < 0

C) is spontaneous D) will have more products than reactants at equilibrium E) all of the above Answer: E

Difficulty: Medium Section Reference: 1-3 Learning Objective: Explain how enthalpy, entropy, and free energy apply to biological systems 12) Which of the following molecules contains the most oxidized form of carbon?

A) acetaldehyde B) ethanol C) acetic acid D) ethylene E) carbon dioxide Answer: E Difficulty: Easy Section Reference: 1-3 Learning Objective: Explain how enthalpy, entropy, and free energy apply to biological systems

13) If the following two reactions were coupled, what would be the G for the overall exergonic reaction?

ATP + H2O → ADP + Pi Glucose + Pi → glucose-1-phosphate + H2O

G = -31 kJ/mol G = 21 kJ/mol

A) -52 kJ/mol B) -10 kJ/mol C) 10 kJ/mol D) 52 kJ/mol E) none of the above Answer: B Difficulty: Medium Section Reference: 1-3 Learning Objective: Explain how enthalpy, entropy, and free energy apply to biological systems 14) A gaseous mixture of hydrogen, water, ammonia and methane can produce which of the biomolecules when exposed to an electrical discharge (such as lightening)?

A) carbohydrates B) nucleotides C) lipids D) amino acids

E) none of the above Answer: D Difficulty: Medium Section Reference: 1-4 Learning Objective: Summarize the evolutionary history of cells 15) Which of the following explains how nucleotides might have polymerized into nucleic acids in the prebiotic world?

A) a mixture of hydrogen cyanide, formaldehyde and phosphate can form nucleotides in the presence of an electrical discharge B) nucleotides formed short polymers in the high temperatures of hydrothermal vents C) nucleotides used the surface of clay as a catalyst to form polymers D) catalysts such as iron sulfide allow for the formation of new C—C bonds E) all of the above Answer: C Difficulty: Hard Section Reference: 1-4 Learning Objective: Summarize the evolutionary history of cells

16) Photosynthetic organisms use energy from the sun to reduce _____ to _____.

A) formaldehyde; ethanol B) CO2; ethanol C) CO2; carbohydrates D) CO2; oxygen E) none of the above Answer: C Difficulty: Medium Section Reference: 1-4 Learning Objective: Summarize the evolutionary history of cells

17) The biological classification system categorizes organisms into which of the following domains?

A) bacteria and eukarya B) prokarya and eukarya C) archaea and eukarya

D) bacteria, eukarya and prokarya E) bacteria, archaea and eukarya Answer: E Difficulty: Medium Section Reference: 1-4 Learning Objective: Summarize the evolutionary history of cells

18) Which of the following is a major difference between eukaryotic and prokaryotic cells?

A) eukaryotic cells contain a nucleus, prokaryotic cells do not B) eukaryotic cells contain organelles, prokaryotic cells do not C) eukaryotic cells are much larger than prokaryotic cells D) eukaryotic cells often form multicellular organisms, prokaryotic cells do not E) all of the above Answer: E Difficulty: Easy Section Reference: 1-4 Learning Objective: Summarize the evolutionary history of cells 19) The similarity of one organism to another (for example a bacteria versus a human) is most easily done by comparing which biopolymer?

A) nucleic acids B) polysaccharides C) proteins D) lipids E) all of the above Answer: A Difficulty: Medium Section Reference: 1-4 Learning Objective: Summarize the evolutionary history of cells

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 2 Question type: Multiple Choice 1) In a water molecule, hydrogens are partially _____; oxygens are partially _____.

A) negative; negative B) negative; positive C) positive; positive D) positive; negative E) none of the above Answer: D Difficulty: Easy Section Reference: 2-1 Learning Objective: Explain water’s properties in terms of its ability to form hydrogen bonds

2) At any given moment, a single water molecule participates in _____ strong hydrogen bond(s).

The role played by the water molecule is best characterized as _____.

A) two ; one H-bond donor, one H-bond acceptor B) two ; two H-bond donor C) two ; two H-bond acceptor D) one; H-bond donor E) one; H-bond acceptor Answer: A Difficulty: Medium Section Reference: 2-1 Learning Objective: Explain water’s properties in terms of its ability to form hydrogen bonds

3) Which of the following is a physical property of water that results from hydrogen bonding?

A) high boiling point relative to molecular weight B) a solid state that is less dense than the liquid state C) high surface tension D) ability to solubilize polar molecules E) all of the above

Answer: E Difficulty: Medium Section Reference: 2-1 Learning Objective: Explain water’s properties in terms of its ability to form hydrogen bonds

4) In a hydrogen bond between a water molecule and another biomolecule, _____.

A) a hydrogen ion on the water molecule forms an ionic bond with a hydride ion on the other molecule B) the hydrogen bond will typically form between a hydrogen atom and either a nitrogen, sulfur, or oxygen atom C) the partial charge on a hydrogen of the water interacts with the partial charge on a hydrogen of the other molecule D) a hydrogen on the water molecule forms a covalent bond to an oxygen or nitrogen atom on the other molecule E) the hydrogen atom is located between an oxygen atom of the water and a carbon atom of the other molecule Answer: B Difficulty: Medium Section Reference: 2-1 Learning Objective: Explain water’s properties in terms of its ability to form hydrogen bonds

5) The strongest non-covalent interactions are _____.

A) van der Waals interactions B) London dispersion forces C) hydrogen bonds D) dipole-dipole interactions E) ionic interactions Answer: E Difficulty: Easy Section Reference: 2-1 Learning Objective: Explain water’s properties in terms of its ability to form hydrogen bonds 6) Hydrogen bonds are approximately _____% of the bond strength of covalent C-C or C-H bonds.

A) 1 B) 5 C) 20 D) 50 E) 95 Answer: B Difficulty: Easy Section Reference: 2-1 Learning Objective: Explain water’s properties in terms of its ability to form hydrogen bonds

7) Due to the formation of hydrogen bonds, _____ is highly soluble in water.

A) carbon dioxide B) sodium chloride C) methanol D) octane E) cholesterol Answer: C Difficulty: Medium Section Reference: 2-1 Learning Objective: Explain water’s properties in terms of its ability to form hydrogen bonds 8) Which of the following explains the interactions that occur between the atoms of water molecules and the ions that form when sodium chloride dissolves in water?

A) hydrogens interact with the sodium ion, oxygens interact with the chloride ion B) hydrogens interact with the chloride ion, oxygens interact with the sodium ion C) hydrogens interact with the sodium ion and the chloride ion D) oxygens interact with the sodium ion and the chloride ion E) none of the above Answer: B Difficulty: Medium Section Reference: 2-1 Learning Objective: Explain water’s properties in terms of its ability to form hydrogen bonds 9) Which of the following functional groups has two hydrogen bond donors and one hydrogen

bond acceptor?

A) alcohol B) ester C) thiol D) amine E) amide Answer: D Difficulty: Hard Section Reference: 2-1 Learning Objective: Explain water’s properties in terms of its ability to form hydrogen bonds 10) Hydrogen bonds within liquid water are _________.

A) attractions between the protons of the oxygen nuclei B) ion-induced dipole interactions C) dipole-dipole interactions D) attractions between two oxygen atoms E) attractions between the H+ and –OH ions of the liquid Answer: C Difficulty: Medium Section Reference: 2-1 Learning Objective: Explain water’s properties in terms of its ability to form hydrogen bonds 11) When a non-polar substance is added to water, how do the molecules of water behave?

A) the regular hydrogen bond pattern is disrupted resulting in a decrease of entropy B) the regular hydrogen bond pattern is disrupted resulting in an increase of entropy C) the regular hydrogen bond pattern is disrupted resulting in a decrease of enthalpy D) the regular hydrogen bond pattern is disrupted resulting in an increase of enthalpy E) none of the above Answer: A Difficulty: Medium Section Reference: 2-2 Learning Objective: Relate the solubility of substances to the hydrophobic effect 12) What term is used to describe the exclusion of nonpolar substances from an aqueous

solution?

A) nonpolar effect B) lipid effect C) hydrophobic effect D) oil droplet effect E) amphiphilic effect Answer: C Difficulty: Easy Section Reference: 2-2 Learning Objective: Relate the solubility of substances to the hydrophobic effect

13) Which of the following is an example of the hydrophobic effect?

A) the lipid membrane of cells and organelles B) protein folding that places hydrophobic amino acids in the interior of the protein C) the separation of salad dressing D) oil sheens seen on the ocean following an oil spill E) all of the above Answer: E Difficulty: Easy Section Reference: 2-2 Learning Objective: Relate the solubility of substances to the hydrophobic effect

14) Which of the following explains the attractive forces between hydrophobic molecules in an aqueous solution?

A) in an aqueous environment, London dispersion forces between hydrophobic molecules become stronger B) in an aqueous environment, London dispersion forces between hydrophobic molecules and water become stronger C) since nonpolar molecules do not form hydrogen bonds with hydrogen bonds with water, they can form hydrogen bonds with other nonpolar molecules D) there is no increase in attractive forces between nonpolar molecules in an aqueous environment E) none of the above Answer: D Difficulty: Hard

Section Reference: 2-2 Learning Objective: Relate the solubility of substances to the hydrophobic effect 15) Considering the energetics of transferring nonpolar molecules from water to a nonpolar

solvent, the factor TS is generally _____, causing G to be _____.

A) positive; negative B) negative; negative C) positive; positive D) positive; positive E) negligible; either positive or negative Answer: A Difficulty: Hard Section Reference: 2-2 Learning Objective: Relate the solubility of substances to the hydrophobic effect 16) A molecule that has both a polar and nonpolar region is called _____________.

A) micelleic B) amphiphilic C) endergonic D) a membrane E) none of the above Answer: B Difficulty: Easy Section Reference: 2-2 Learning Objective: Relate the solubility of substances to the hydrophobic effect 17) Which of the following is an example of an amphipathic molecule?

A) adenine, a base found in nucleic acids B) glucose, a monosaccharide C) serine, an amino acid D) palmitic acid, a fatty acid E) none of the above Answer: D Difficulty: Medium

Section Reference: 2-2 Learning Objective: Relate the solubility of substances to the hydrophobic effect 18) In aqueous solution, globules of up to several thousand amphiphilic molecules arranged with the hydrophilic groups on the surface and the hydrophobic groups buried in the center are called _____.

A) micelles B) vacuoles C) liposomes D) bilayers E) none of the above Answer: A Difficulty: Easy Section Reference: 2-2 Learning Objective: Relate the solubility of substances to the hydrophobic effect

19) Fatty acid anions most commonly assemble into _____ in aqueous solution.

A) lipid bilayers B) solvent-filled vesicles C) micelles D) liposomes E) none of the above Answer: C Difficulty: Easy Section Reference: 2-2 Learning Objective: Relate the solubility of substances to the hydrophobic effect

20) Which of the following molecules would be prevented from readily crossing a lipid bilayer?

A) glucose B) sodium ions C) potassium ions D) water E) all of the above Answer: E

Difficulty: Medium Section Reference: 2-2 Learning Objective: Relate the solubility of substances to the hydrophobic effect 21) Which of the following is true regarding hydrophobic interactions between nonpolar molecules or groups?

A) they result from the tendency to maximize water's contact with nonpolar molecules B) they require the presence of surrounding water molecules C) they are the result of strong attractions between nonpolar regions D) they are the result of strong repulsion between water and nonpolar regions E) they depend on strong permanent dipoles in the nonpolar molecules Answer: B Difficulty: Medium Section Reference: 2-2 Learning Objective: Relate the solubility of substances to the hydrophobic effect 22) In an aqueous solution, if the [OH-] is 3.010-5 M, what is the [H+]?

A) 7.010-9 B) 7.010-2 C) 3.310-3 D) 3.310-10 E) none of the above Answer: D Difficulty: Medium Section Reference: 2-3 Learning Objective: Calculate the effect of acids and bases on a solution’s pH 23) What is the [H+] of an aqueous solution with a pH of 6.2?

A) 6.210-6 B) 1.610-8 C) 6.310-7 D) 3. 310-5 E) none of the above Answer: C

Difficulty: Medium Section Reference: 2-3 Learning Objective: Calculate the effect of acids and bases on a solution’s pH 24) What would be the resulting pH if one drop (0.05 ml) of 1.0 M HCl was added to one liter of pure water (assume pH 7.0)? A) 2.7 B) 4.3 C) 5.0 D) 7.0 (there would be no significant change) E) 9.7 Answer: B Difficulty: Hard Section Reference: 2-3 Learning Objective: Calculate the effect of acids and bases on a solution’s pH

25) What would be the resulting pH if one ml of 1.0 M NaOH was added to one liter of pure water (assume pH 7.0)?

A) 1 B) 3 C) 7.3 D) 11 E) 13 Answer: D Difficulty: Medium Section Reference: 2-3 Learning Objective: Calculate the effect of acids and bases on a solution’s pH

26) Which of the following would be the strongest acid?

A) formic acid, pK=3.75 B) succinic acid, a diprotic acid with pK=4.21 and 5.64 C) acetic acid, pK=4.76 D) ammonium ion, pK=9.25 E) cannot be determined from the given information Answer: A

Difficulty: Easy Section Reference: 2-3 Learning Objective: Calculate the effect of acids and bases on a solution’s pH 27) What is the pH of a solution that contains three parts of acetic acid and one part sodium acetate? The pK for acetic acid is 4.76.

A) 5.24 B) 5.06 C) 4.46 D) 4.28 E) cannot be determined from the given information Answer: D Difficulty: Medium Section Reference: 2-3 Learning Objective: Calculate the effect of acids and bases on a solution’s pH 28) If the pK values for phosphoric acid are 2.15, 6.82 and 12.38, at what pH would one observe 2equal amounts of HPO4 and HPO4?

2 A) 2.15 B) 4.49 C) 6.82 D) 9.60 E) 12.38 Answer: C Difficulty: Medium Section Reference: 2-3 Learning Objective: Calculate the effect of acids and bases on a solution’s pH 29) If 1.0 mL of 1.0 M acetic acid (pK = 4.76, K = 1.74 x 10–5) was added to one liter of pure water, what is the resulting pH? A) 1.0 B) 1.3 C) 3.0 D) 3.9 E) 10.1

Answer: D Difficulty: Hard Section Reference: 2-3 Learning Objective: Calculate the effect of acids and bases on a solution’s pH 30) If the pK values for phosphoric acid are 2.15, 6.82 and 12.38, _____ would predominate at pH 5 while _____ would predominate at pH 10.

A) H 3PO4; H2PO4 2B) H 3PO4; HPO4 3C) H 3PO4; PO4 D) H 2PO4; PO43E) H 2PO4; HPO42-

Answer: E Difficulty: Medium Section Reference: 2-3 Learning Objective: Calculate the effect of acids and bases on a solution’s pH 31) What is the conjugate acid of2HPO4?

A) HPO2-4 B) H2PO4 C) H3PO4 D) PO3-4 E) none of the above Answer: C Difficulty: Easy Section Reference: 2-3 Learning Objective: Calculate the effect of acids and bases on a solution’s pH 32) Considering a 0.1 M formic acid buffer, what is the concentration of formic acid present in a solution of pH 4.25 if the pK of formic acid is 3.75?

A) 0.024 M B) 0.033 M C) 0.067 M D) 0.076 M E) none of the above

Answer: A Difficulty: Hard Section Reference: 2-4 Learning Objective: Describe how buffer solutions resist changes in pH 33) Which of the following shows the buffer that is found in the blood stream?

A) H 3PO4 B) H 2PO-4 C) HPO24 D) H 2CO3 E) HCO3

H2PO24 + H+ HPO24 + H+ + PO34 +H HC O3 + H + + CO23 +H

Answer: D Difficulty: Medium Section Reference: 2-4 Learning Objective: Describe how buffer solutions resist changes in pH 34) Which of the following shows the intracellular buffer?

A) H 3PO4 B) H 2PO-4 C) HPO24 D) H 2CO3 E) HCO3

H2PO24 + H+ HPO24 + H+ + PO34 +H HC O3- + H + + CO23 +H

Answer: B Difficulty: Medium Section Reference: 2-4 Learning Objective: Describe how buffer solutions resist changes in pH 35) If a phosphate buffer (pK=6.82) was formulated such that its pH was 7.3, it would be best suited to buffer against _____. If instead, it was formulated such that its pH was 6.3, it would be best suited to buffer against _____.

A) acid; base B) acid; acid C) base; acid D) base; base

E) a buffer with a pH that far from the pK would not be an effective buffer Answer: A Difficulty: Hard Section Reference: 2-4 Learning Objective: Describe how buffer solutions resist changes in pH 36) Which of the following could be used to formulate 100 mls of a 0.10 M acetate buffer (pK=4.76) at pH 5 if you start with 64 mls of 0.10 M sodium acetate?

A) 3.6 mls of 1 M HCl B) 3.6 mls of 1 M NaOH C) 34 mls of 0.10 M HCl D) 34 mls of 0.10 M NaOH E) 34 mls of 0.10 M acetic acid Answer: E Difficulty: Hard Section Reference: 2-4 Learning Objective: Describe how buffer solutions resist changes in pH 37) Which of the following could be used to formulate 100 mls of a 0.10 M phosphate buffer (pK=6.82) at pH 7.2?

A) 2.9 mmoles of Na2HPO4 and 7.1 mmoles of NaHPO4 B) 10 mmoles of Na2HPO4 and 7.1 mmoles of NaOH C) 10 mmoles of NaHPO4 and 7.1 mmoles of HCl D) 10 mmoles of H3PO4 and 17.1 mmoles of NaOH E) all of the above Answer: E Difficulty: Hard Section Reference: 2-4 Learning Objective: Describe how buffer solutions resist changes in pH

38) Metabolic acidosis often causes increased respiratory rates. What portion of the bloodstream buffer is lost through increased respiration?

A) H+ B) HCO-3

C) H2CO3 D) CO2 E) H2O Answer: D Difficulty: Easy Section Reference: 2-4 Learning Objective: Describe how buffer solutions resist changes in pH

39) What is the resulting pH if 10 millimoles of HCl is added to 1 liter of a 0.1 M phosphate buffer at pH 7.00 (pK=6.82)?

A) 6.82 B) 6.98 C) 7.01 D) 7.19 E) cannot be determined Answer: A Difficulty: Hard Section Reference: 2-4 Learning Objective: Describe how buffer solutions resist changes in pH 40) During vigorous exercise, hydrogen ions are produced within cells as a result of increased metabolism. What component of the intracellular buffer would increase as a result of the increased H+ production?

A) H3PO4 4 B) HPO2 C) HPO2-4 D) PO3-4 E) none of the above Answer: B Difficulty: Medium Section Reference: 2-4 Learning Objective: Describe how buffer solutions resist changes in pH

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 3 Question type: Multiple Choice 1) Which of the following is a characteristic of Chargaff’s rules? A) A + T = C + G B) A + G = C + T C) A + G = C + U D) all organisms have identical amounts of all four nucleotides E) none of the above Answer: B Difficulty: Medium Section Reference: 3-1 Learning Objective: Describe the structural features of DNA and RNA 2) A base found exclusively in DNA is _____ while _____ is found only in RNA. A) adenine; cytosine B) guanine; thymine C) uracil; adenine D) cytosine; guanine E) thymine; uracil Answer: E Difficulty: Easy Section Reference: 3-1 Learning Objective: Describe the structural features of DNA and RNA

3) The purines found in nucleic acids are _____ and _____. A) adenine; cytosine B) guanine; thymine C) uracil; adenine D) adenine; guanine E) thymine; uracil Answer: D

Difficulty: Easy Section Reference: 3-1 Learning Objective: Describe the structural features of DNA and RNA 4) In DNA, the ribose derivative lacks an _____ on carbon _____.

A) alcohol; 2 B) alcohol; 3 C) amine; 2 D) amine; 3 E) none of the above Answer: A Difficulty: Medium Section Reference: 3-1 Learning Objective: Describe the structural features of DNA and RNA

5) Which of the following is correctly paired with its nucleoside?

A) adenine: adenylate B) cytosine: cytidine diphosphate C) guanine: guanosine D) thymine: thymidylate E) uridine: uridine triphosphate Answer: C Difficulty: Medium Section Reference: 3-1 Learning Objective: Describe the structural features of DNA and RNA

6) The coenzymes known as NAD+, FAD and coenzyme A all contain a derivative of _____. A) adenosine B) cytidine C) guanosine D) thymidine E) uridine Answer: A

Difficulty: Medium Section Reference: 3-1 Learning Objective: Describe the structural features of DNA and RNA 7) What type of bond is made between nucleotides?

A) ester B) phosphate ester C) phosphodiester D) glycosidic E) none of the above Answer: C Difficulty: 1 Section Reference: 3-1 Learning Objective: Describe the structural features of DNA and RNA 8) The 5 end of a polynucleotide contains _____ while the 3 end contains _____.

A) a hydroxyl group; a phosphate group B) a phosphate group; a hydroxyl group C) a phosphate group; a phosphate group D) a hydroxyl group; a hydroxyl group E) none of the above Answer: B Difficulty: Easy Section Reference: 3-1 Learning Objective: Describe the structural features of DNA and RNA 9) The most common base pairs in DNA are _____ and _____.

A) A-T; A-G B) G-C; C-A C) T-A; A-U D) C-G; T-A E) G-U; A-T Answer: D Difficulty: Medium

Section Reference: 3-1 Learning Objective: Describe the structural features of DNA and RNA 10) An A-T base pair consists of _____ H-bond(s); a C-G base pair consists of _____ H- bond(s). A) 1; 2 B) 2; 1 C) 2; 2 D) 3; 2 E) 2; 3 Answer: E Difficulty: Easy Section Reference: 3-1 Learning Objective: Describe the structural features of DNA and RNA

11) Which of the following correctly describes the B-DNA double helix?

A) antiparallel strands B) right-handed helix C) base pairs are located in the center of the helix D) one helical rotation has a rise of 3.4 nm E) all of the above Answer: E Difficulty: Hard Section Reference: 3-1 Learning Objective: Describe the structural features of DNA and RNA

12) Differences in structure between a DNA helix and an RNA helix can predominantly be attributed to the presence of _____ in RNA. A) uracil B) 2 hydroxyl group C) 3 hydroxyl group D) smaller sizes of RNA molecules E) none of the above Answer: B

Difficulty: Medium Section Reference: 3-1 Learning Objective: Describe the structural features of DNA and RNA 13) Which of the following non-covalent interactions is the most important in maintaining the structure of the double helix?

A) phosphodiester bonds B) hydrogen bonds C) London dispersion forces D) van der Waals interactions E) ionic interactions Answer: D Difficulty: Medium Section Reference: 3-1 Learning Objective: Describe the structural features of DNA and RNA

14) What term describes the process of converting the information found in DNA into the sequence of a protein?

A) replication B) transcription C) translation D) expression E) none of the above Answer: D Difficulty: Easy Section Reference: 3-2 Learning Objective: Summarize the biological roles of DNA and RNA

15) The DNA strand that serves as the template for the synthesis of RNA is often called the _____. A) coding strand B) noncoding strand C) messenger strand D) transfer strand E) transcription strand

Answer: B Difficulty: Easy Section Reference: 3-2 Learning Objective: Summarize the biological roles of DNA and RNA 16) If instead of four different bases in DNA and RNA, there were six, what is the minimum size of a codon to encode the 20 amino acids commonly found in proteins?

A) 1 B) 2 C) 3 D) 4 E) cannot be determined Answer: B Difficulty: Hard Section Reference: 3-2 Learning Objective: Summarize the biological roles of DNA and RNA 17) The replication of DNA is made possible by the presence of _____ strands in the double helix of DNA. A) antiparallel B) hydrogen bonded C) complementary D) genomic E) none of the above Answer: C Difficulty: Easy Section Reference: 3-2 Learning Objective: Summarize the biological roles of DNA and RNA 18) Which of the following represents a DNA mutation in the template strand that would convert serine to cysteine?

A) 5-GCT-3 to 5-GCA-3 B) 5-AGC-3 to 5-TGC-3 C) 5-AGC-3 to 5-UGC-3 D) 5-AGU-3 to 5-UGU-3

E) 5-TCG-3 to 5-TCC-3 Answer: A Difficulty: Hard Section Reference: 3-3 Learning Objective: Identify the types of information provided by genomic analysis 19) The triplet code allows many amino acids to be specified by more than one codon. Such a code is said to be _____.

A) conclusive B) elusive C) replicative D) recursive E) degenerate Answer: E Difficulty: Medium Section Reference: 3-3 Learning Objective: Identify the types of information provided by genomic analysis 20) Bacteria and archaea typically have fewer than _____ genes while plants and animals typically have greater than _____ genes.

A) 200; 1,000 B) 500; 2,500 C) 1,000; 5,000 D) 5,000; 10,000 E) 10,000; 100,000 Answer: D Difficulty: Medium Section Reference: 3-3 Learning Objective: Identify the types of information provided by genomic analysis 21) What term is used to describe short segments of DNA that are copied many times and inserted randomly in chromosomes?

A) moderately repetitive sequences B) highly repetitive sequences

C) transposable elements D) spliced sequences E) none of the above Answer: C Difficulty: Medium Section Reference: 3-3 Learning Objective: Identify the types of information provided by genomic analysis

22) An open reading frame is defined by _____.

A) a start and stop codon B) homology with other species C) placement on a genome map D) presence of transposable elements E) absence of highly repetitive sequences Answer: A Difficulty: Medium Section Reference: 3-3 Learning Objective: Identify the types of information provided by genomic analysis 23) The presence of _____ approximately once in every 1000 base pairs is what makes each individual human genetically unique.

A) orphan genes B) horizontal genes C) homologous genes D) transposable elements E) single nucleotide polymorphisms Answer: E Difficulty: Medium Section Reference: 3-3 Learning Objective: Identify the types of information provided by genomic analysis 24) A genomic library _____.

A) contains only protein-coding DNA sequences B) is built from mRNA by reverse transcription

C) is a storehouse of protein structures for a specific organism D) contains all of an organism's DNA E) is best constructed from very short DNA fragments Answer: D Difficulty: Medium Section Reference: 3-3 Learning Objective: Identify the types of information provided by genomic analysis

25) In humans, approximately _____ % of the genome encodes proteins.

A) 78 B) 45 C) 33 D) 11 E) 1.5 Answer: E Difficulty: Medium Section Reference: 3-3 Learning Objective: Identify the types of information provided by genomic analysis 26) Incorporation of which of the following would result in chain termination during sequencing of DNA? A) dATP B) dCTP C) ddTTP D) dGTP E) none of the above Answer: C Difficulty: Easy Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA 27) The results of DNA sequencing are obtained by first separating different sized pieces of DNA using _____ followed by detection of the particular dideoxynucleotide using _____.

A) HPLC; NMR

B) HPLC; absorbance spectroscopy C) electrophoresis; fluorescence spectroscopy D) electrophoresis; x-ray crystallography E) none of the above Answer: C Difficulty: Medium Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA

28) What reagents are required for the Sanger sequencing method?

A) template, primer, DNA polymerase, mRNA, dNTPs, ddNTP B) template, primer, DNA polymerase, dNTPs, ddNTP C) template, primer, DNA polymerase, rRNA, dNTPs, ddNTP D) template, primer, DNA polymerase, mRNA, dNTPs E) none of the above Answer: B Difficulty: Medium Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA

29) The most commonly used technique for making large numbers of copies of DNA is _____. A) polymerase chain reaction B) dideoxy sequencing C) restriction digestion D) genetic engineering E) site-directed mutagenesis Answer: A Difficulty: Easy Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA

30) Because of the high temperature _____ step during a PCR reaction, the DNA polymerase from _____ is used.

A) primer extension; E. coli

B) strand separation; Thermus aquaticus C) primer annealing; Thermus aquaticus D) primer extension; bacteriophage  E) strand separation; E. coli Answer: B Difficulty: Medium Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA 31) What reagents are required to perform PCR? A) DNA fragment, primers flanking the region of interest, dNTPs, DNA polymerase B) DNA fragment, primers flanking the region of interest, dNTPs, ddNTPs, DNA polymerase C) DNA fragment, one primer, dNTPs, DNA Polymerase, DNA ligase D) DNA fragment, one primer, dNTPs, DNA Polymerase, DNA endonuclease E) DNA fragment, primers flanking the region of interest, dNTPs, DNA endonuclease Answer: A Difficulty: Medium Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA 32) Which of the following represents the correct order of steps in a PCR reaction beginning with double stranded DNA? A) primer annealing, strand separation, primer extension B) strand separation, primer extension, primer annealing C) strand separation, primer annealing, primer extension D) primer extension, primer annealing, strand separation E) primer annealing, primer extension, strand separation Answer: C Difficulty: Medium Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA 33) What technique that is commonly used in forensics relies upon PCR to examine segments of repetitive DNA sequences?

A) cloning B) transformation C) DNA sequencing D) DNA restriction E) DNA fingerprinting Answer: E Difficulty: Easy Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA

34) Which of the following is a palindromic sequence?

A) GAATTC B) GATTAG C) CATTAG D) ATCCTA E) GATATG Answer: A Difficulty: Hard Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA 35) EcoRI recognizes the sequence 5-GAATTC-3 (the arrow indicates the point of cleavage).

Treatment of the following oligonucleotide with EcoRI would produce two oligonucleotides with sizes of _____ nucleotides containing _____ ends.

5-AAGTCGATACAGAATTCGTACCTAG-3 A) 12 and 13; blunt B) 12 and 8; blunt C) 11 and 8; sticky D) 12 and 13; sticky E) 9 and 13; sticky Answer: D Difficulty: Hard Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA

36) What term describes a small, circular molecule of DNA that can be used to transfer genetic material from one organism to another?

A) plasmid B) bacteriophage C) clone D) tRNA E) splice Answer: A Difficulty: Easy Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA

37) What term describes the production of multiple identical organisms from a single ancestor?

A) transcription B) cloning C) sequencing D) phenotyping E) ligation Answer: B Difficulty: Easy Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA 38) What enzyme is required to form a new phosphodiester bond when inserting DNA into a plasmid?

A) DNA polymerase B) endonuclease C) exonuclease D) ligase E) clonase Answer: D Difficulty: Easy Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA

39) What technique involves addition of primers that do not exactly match the sequence of a gene, thus allowing for introduction of a mutation?

A) cloning B) transformation C) site-directed mutagenesis D) selection E) none of the above Answer: C Difficulty: Easy Section Reference: 3-4 Learning Objective: Describe the procedures used to study DNA

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 4 Question type: Multiple Choice 1) When a peptide bond forms, a(n) ___ reacts with a carboxylate group. a) amide b) amine c) alcohol d) ester e) none of these choices Answer: b Difficulty: easy Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 2) At a pH above its pKa, the phenolic group of tyrosine is ___. a) protonated and neutral b) protonated and positively charged c) deprotonated and neutral d) deprotonated and negatively charged e) none of these choices Answer: d Difficulty: medium Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 3) At a pH above its pKa, the -amino group of lysine is ___. a) protonated and neutral b) protonated and positively charged c) deprotonated and neutral d) deprotonated and negatively charged e) none of these choices

Answer: b Difficulty: medium Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 4) At a pH above its pKa, the R-group of Asp is ___. a) protonated and neutral b) protonated and positively charged c) deprotonated and neutral d) deprotonated and negatively charged e) none of these choices Answer: d Difficulty: medium Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 5) What is the C-terminal amino acid in the pentapeptide Val-Leu-Arg-Ser-Gly? a) Val b) Leu c) Arg d) Ser e) Gly Answer: e Difficulty: easy Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 6) At pH 3, how many charged groups are present in the pentapeptide Ala-Asp-His-Ser-Lys? a) 1 b) 2 c) 3 d) 4 e) 5 Answer: d

Difficulty: medium Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 7) Which of the following structures shows the prevalent form of glutamic acid at pH 3?

a) a b) b c) c d) d e) none of these choices Answer: c Difficulty: hard Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1

8) Which of the following amino acids has a positively charged side chain at pH 7.4? a) Glu b) Ala c) Lys d) Leu e) His Answer: c Difficulty: medium Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1

9) Which of the following amino acids has a thiol group in its side chain? a) Ser b) Asn c) Cys d) Tyr e) Met Answer: c Difficulty: easy Learning properties.Objective 1: Classify the 20 amino acids according to their chemical Section Reference 1: 4-1

10) Which of the following amino acids has a nonpolar side chain? a) Ser b) Val c) Lys d) Asn e) none of these choices Answer: b Difficulty: easy Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 11) Which of the following amino acids contains a side chain that is polar and uncharged from pH 1-13? a) Phe b) Tyr c) Asp d) Gln e) Ile Answer: d Difficulty: medium Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1

12) Which of the following structures shows the prevalent form of histidine at pH 5?

a) a b) b c) c d) d e) none of these choices Answer: c Difficulty: hard Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1

13) At pH ___, the pentapeptide Ala-Glu-His-Val-Cys would contain two positively charged groups and one negatively charged group. a) 1 b) 3 c) 5 d) 7 e) 9 Answer: b Difficulty: hard Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 14) Disulfide bonds form between two residues of which amino acid? a) Met b) Ser c) Asn

d) Thr e) Cys Answer: e Difficulty: easy Learning properties.Objective 1: Classify the 20 amino acids according to their chemical Section Reference 1: 4-1

15) Based upon its side chain, how is the amino acid Ser classified? a) non-polar b) polar c) positively charged d) negatively charged e) none of these choices Answer: b Difficulty: easy Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 16) At physiological pH, all amino acids have at least ___ charged groups. a) 0 b) 1 c) 2 d) 3 e) cannot be determined Answer: c Difficulty: easy Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 17) Which of the following structures shows the prevalent form of cysteine at pH 12?

a) a b) b c) c d) d e) none of these choices Answer: d Difficulty: hard Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1

18) The formation of a dipeptide from two amino acids requires ___. a) reduction of the -carboxyl group b) protonation of the -amine group c) interaction of the two side-chains d) loss of water e) none of these choices Answer: d Difficulty: easy Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 19) What is the net charge of the pentapeptide Ala-Cys-Ser-Glu-Asn at pH 7? a) -2 b) -3 c) 0 d) +1 e) none of these choices Answer: b

Difficulty: medium Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 20) What level of protein structure is characterized by the amino acid sequence? a) primary b) secondary c) tertiary d) quaternary e) none of these choices Answer: a Difficulty: easy Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 21) What level of protein structure is characterized by the three dimensional structure of an entire polypeptide including all amino acid side chains? a) primary b) secondary c) tertiary d) quaternary e) none of these choices Answer: c Difficulty: easy Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 22) What is the N-terminal residue of the peptide AYSDG? a) glutamic acid b) glycine c) aspartic acid d) alanine e) none of these choices Answer: d

Difficulty: medium Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 23) Which of the 20 standard amino acids is optically inactive? a) Arg b) Pro c) Ile d) Gly e) Cys Answer: d Difficulty: easy Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 24) If a protein underwent a mutation such that a Glu residue was changed to another amino acid, which of the following amino acids would least likely result in a change in the overall structure of the protein? a) Ser b) Asp c) Gln d) Lys e) Ala Answer: b Difficulty: medium Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Learning Objective 2: Describe the forces that stabilize protein structure.

Section Reference 1: 4-1 and 4-3 25) Since there are 20 standard amino acids, the number of possible linear polypeptides of length N can be expressed as ___. a) 20  10N b) N20 c) N  1020 d) 20N e) N  20

Answer: d Difficulty: hard Learning Objective 1: Classify the 20 amino acids according to their chemical properties.

Section Reference 1: 4-1 26) In the following figure, which bond would be unable to rotate?

a) a b) b c) c d) d e) none of these choices Answer: b Difficulty: medium Learning Objective 1: Recognize the common types of protein secondary structure.

Section Reference 1: 4-2 27) The predominant non-covalent interaction seen in -helices and -sheets is ___. a) electrostatic interactions b) hydrogen bonds c) dipole-dipole interactions d) hydrophobic interactions e) all of these choices Answer: b Difficulty: medium Learning Objective 1: Recognize the common types of protein secondary structure.

Section Reference 1: 4-2

28) Which of the following amino acids is generally absent from an -helix? a) Trp b) Ser c) Ile d) Pro e) none of these choices Answer: d Difficulty: medium Learning Objective 1: Recognize the common types of protein secondary structure.

Section Reference 1: 4-2

29) -helices and -sheets comprise ___ structure. a) primary b) secondary c) tertiary d) quaternary e) none of these choices Answer: b Difficulty: easy Learning Objective 1: Recognize the common types of protein secondary structure.

Section Reference 1: 4-2 30) Which of the following best describes the peptide backbone in a -sheet? a) coiled b) compacted c) highly extended d) rigid e) none of these choices Answer: c Difficulty: medium Learning Objective 1: Recognize the common types of protein secondary structure.

Section Reference 1: 4-2

31) If an -helical region of a protein contained 18 amino acid residues, how many helical turns would be present? a) 3.33 b) 4 c) 5 d) 6 e) none of these choices Answer: c Difficulty: hard Learning Objective 1: Recognize the common types of protein secondary structure.

Section Reference 1: 4-2

32) Which of the following atoms would be considered a hydrogen bond donor in an -helix?

a) a b) b c) c d) d e) none of these choices Answer: a Difficulty: medium Learning Objective 1: Recognize the common types of protein secondary structure.

Section Reference 1: 4-2 33) The following is an example of ___.

a) parallel -helix b) parallel -sheet c) antiparallel -helix d) antiparallel -sheet e) none of these choices Answer: d Difficulty: medium Learning Objective 1: Recognize the common types of protein secondary structure.

Section Reference 1: 4-2 34) Lysine can form a salt bridge by interacting with the side chain of ___. a) Glu b) Gly c) Asn d) Ser e) Pro Answer: a Difficulty: medium Learning Objective 1: Describe the forces that stabilize protein structure.

Section Reference 1: 4-3 35) The side chain of serine could interact with the side chain of ___ using a(n) ___. a) Val; hydrophobic interaction b) His; hydrogen bond c) Gln; hydrophobic interaction d) Asn; electrostatic interaction e) none of these choices

Answer: b Difficulty: hard Learning Objective 1: Describe the forces that stabilize protein structure.

Section Reference 1: 4-3 36) For a globular protein that is found in the cytosol, ___ would most likely be found in the proteins interior while ___ would most likely be found on the surface. a) Val; Phe b) Leu; Ile c) Leu; Ser d) Thr; His e) none of these choices Answer: c Difficulty: hard Learning Objective 1: Describe the forces that stabilize protein structure.

Section Reference 1: 4-3 37) Which of the following is most critical for maintaining the tertiary structure of a protein? a) hydrogen bonds b) hydrophobic interactions c) disulfide bonds d) salt bridges e) none of these choices Answer: b Difficulty: medium Learning Objective 1: Describe the forces that stabilize protein structure.

Section Reference 1: 4-3 38) Molecular chaperones assist proteins in the formation of ___. a) aggregates b) tertiary structure c) peptide bonds d) primary structure e) none of these choices

Answer: b Difficulty: easy Learning Objective 1: Describe the forces that stabilize protein structure.

Section Reference 1: 4-3 39) The amino acid ___ is commonly phosphorylated. a) Ser b) Asp c) Asn d) His e) none of these choices Answer: a Difficulty: medium Learning Objective 1: Describe the forces that stabilize protein structure.

Section Reference 1: 4-3 40) Which of the following interactions would be involved in quaternary structure? a) hydrogen bonds b) hydrophobic interactions c) disulfide bonds d) salt bridges e) all of these choices Answer: e Difficulty: easy Learning Objective 1: Recognize quaternary structure in proteins.

Section Reference 1: 4-4 41) If the following mixture of proteins was applied to a size-exclusion chromatography column, what would be the order of elution?

Proteins with molecular weights: myoglobin (17.7 kDa) , hemoglobin (64.5 kDa) , lysozyme (14.3 kDa) and triose phosphate isomerase (57.4 kDa) a) lysozyme, myoglobin, triose phosphate isomerase, hemoglobin b) triose phosphate isomerase, hemoglobin, lysozyme, myoglobin c) hemoglobin, myoglobin, lysozyme, triose phosphate isomerase

d) hemoglobin, triose phosphate isomerase, myoglobin, lysozyme, e) cannot be determined Answer: d Difficulty: medium Learning Objective 1: Describe the techniques for purifying and analyzing proteins.

Section Reference 1: 4-5

42) Given pKa values of 2.3 and 9.7, what is the pI of alanine? a) 12 b) 7.4 c) 6 d) 4.2 e) none of these choices Answer: c Difficulty: medium Learning Objective 1: Describe the techniques for purifying and analyzing proteins.

Section Reference 1: 4-5 43) Given pKa values of 2.1, 9.8 and 3.9 (side chain), what is the pI of aspartic acid? a) 6.0 b) 6.9 c) 5.3 d) 3.0 e) none of these choices Answer: d Difficulty: hard Learning Objective 1: Describe the techniques for purifying and analyzing proteins.

Section Reference 1: 4-5 44) Which of the following methods for cleaving a protein is properly identified? a) chymotrypsin: cleaves on the C-terminal side of Lys or Arg b) trypsin: cleaves on the C-terminal side of Ala or Val c) cyanogen bromide: cleaves on the C-terminal side of Met d) elastase: cleaves on the C-terminal side of Phe, Trp or Tyr

e) none of these choices Answer: c Difficulty: medium Learning Objective 1: Describe the techniques for purifying and analyzing proteins.

Section Reference 1: 4-5 45) What are the products from treatment of the following peptide with chymotrypsin?

Met-Tyr-Ala-Ser-Phe-Val-Lys-Asn-His-Tyr-Gly-Arg-Met-Trp a) 1 tripeptide, 1 tetrapeptide, 1 pentapeptide, and two free amino acids b) 1 dipeptide, 1 tripeptide, 1 tetrapeptide and 1 pentapeptide c) 1 dipeptide, 1 tetrapeptide and 1 octapeptide d) 1 dipeptide, 2 tripeptides, 1 pentapeptide and one free amino acid e) none of these choices Answer: b Difficulty: hard Learning Objective 1: Describe the techniques for purifying and analyzing proteins.

Section Reference 1: 4-5 46) What are the products from treatment of the following peptide with trypsin?

Leu-Val-Ala-Arg-Phe-Val-Lys-Asn-Leu-Gly-Arg-Cys-Asp a) 2 dipeptides, 1 tripeptide and 1 tetrapeptide b) 3 tripeptides and 1 tetrapeptide c) 2 tripeptides, 1 tetrapeptide and 3 free amino acids d) 1 dipeptide, 1 tripeptide and 2 tetrapeptides e) none of these choices Answer: d Difficulty: hard Learning Objective 1: Describe the techniques for purifying and analyzing proteins.

Section Reference 1: 4-5 47) A technique for determining protein structure that requires crystals of the protein is ___. a) NMR spectroscopy

b) X-ray crystallography c) electron crystallography d) mass spectrometry e) none of these choices Answer: b Difficulty: easy Learning Objective 1: Describe the techniques for purifying and analyzing proteins.

Section Reference 1: 4-5

48) A technique for determining protein structure where the protein is in solution is ___. a) NMR spectroscopy b) X-ray crystallography c) electron crystallography d) mass spectrometry e) none of these choices Answer: a Difficulty: easy Learning Objective 1: Describe the techniques for purifying and analyzing proteins.

Section Reference 1: 4-5

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 5 Question type: Multiple Choice 1) Heme is considered a _____.

A) catalyst B) prosthetic group C) coenzyme D) cofactor E) none of the above Answer: B Difficulty: Easy Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

2) The central ion of the heme group of hemoglobin is _____.

A) Cu+ B) Cu2+ C) Fe2+ D) Fe3+ E) none of the above Answer: C Difficulty: Easy Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

3) When oxygen is bound to the heme group of myoglobin, it is coordinated between _____ and _____. A) F8 His; Fe3+ of heme B) E7 His; Fe3+ of heme C) F8 His; Fe2+ of heme

D) E7 His; Fe2+ of heme E) none of the above Answer: D Difficulty: Medium Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

4) Myoglobin is _____; hemoglobin is _____. A) monomeric; dimeric B) monomeric; trimeric C) monomeric; tetrameric D) dimeric; trimeric E) dimeric; tetrameric Answer: E Difficulty: Medium Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

5) The individual hemoglobin subunits and myoglobin share similar _____ structure but have rather different _____ structure.

A) primary; secondary B) secondary; tertiary C) primary; tertiary D) secondary and tertiary; primary E) primary and secondary; tertiary Answer: D Difficulty: Hard Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

6) What is the prominent type of secondary structure observed in myoglobin?

A) -helices B) -bends C) parallel -sheets D) antiparallel -sheets E) -helices Answer: E Difficulty: Medium Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

7) Which of the following is an example of a conservative amino acid substitution?

A) Ile → Leu B) Ser → Glu C) Phe → Tyr D) Asp → Gln E) Arg → Cys Answer: A Difficulty: Medium Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin 8) While the composition of hemoglobin in adult humans is 22, in the developing fetus, _____ is observed A) 22 B) 22 C) 22 D) 22 E) 22 Answer: E Difficulty: Hard Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

9) The idea that binding of one molecule of oxygen to hemoglobin enhances further binding of oxygen to hemoglobin is called _____.

A) homologous binding B) cooperativity C) fractional saturation D) allosterism E) none of the above Answer: B Difficulty: Medium Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

10) With respect to oxygen saturation, hemoglobin is _____ saturated at the pO2 of the lungs and _____ saturated at the pO2 of the tissue A) 20%; 20% B) 25%; 20% C) 50%; 20% D) 50%; between 30 and 70% E) >90%; between 30 and 70% Answer: E Difficulty: Hard Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin 11) Which of the following best explains the ability for carbon monoxide (CO) to bind to hemoglobin (Hb) despite the relatively low concentrations of CO? A) CO binds to Hb with less affinity than oxygen B) CO binds to Hb with an affinity about the same as oxygen C) CO binds to Hb about 5 times more strongly than oxygen D) CO binds to Hb about 250 times more strongly than oxygen E) none of the above Answer: D

Difficulty: Medium Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin 12) Which of the following occurs in hemoglobin upon oxygen binding?

A) the heme Fe2+ is pulled out of the plane of the heme group B) the His coordinated to the heme Fe2+ is pushed away from the heme group C) the central cavity between the four subunits is decreased in size D) hemoglobin changes from the R state to the T state E) all of the above occur Answer: C Difficulty: Hard Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

13) Which of the following explains the conversion of hemoglobin subunits from deoxy to oxy state? A) all four subunits switch simultaneously B) each subunit switches only upon oxygen binding to the particular subunit C) both  subunits simultaneously switch first followed by both  subunits D) both  subunits simultaneously switch first followed by both  subunits E) none of the above Answer: A Difficulty: Hard Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

14) Proteins such as hemoglobin are known as _____ proteins since binding of a molecule to one site alter binding to other sites.

A) ligand-activated B) allosteric C) induced-fit

D) cooperative E) none of the above Answer: B Difficulty: Medium Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

15) A plot of the binding of oxygen to myoglobin as a function of pO2 gives a _____ shape; a similar plot for hemoglobin gives a _____ shape. A) sigmoidal; sigmoidal B) sigmoidal; hyperbolic C) hyperbolic; sigmoidal D) hyperbolic; hyperbolic E) hyperbolic; exponential Answer: C Difficulty: Medium Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

16) Hemoglobin S, the variant responsible for the misshapen red blood cells characteristic of the disease sickle-cell anemia, is potentially advantageous to heterozygotes because it confers some level of resistance to the disease _____.

A) AIDS B) malaria C) polycythemia D) rickets E) cyanosis Answer: B Difficulty: Easy Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

17) How does CO2 affect hemoglobin-oxygen binding?

A) CO2 binds directly to the oxygen binding site, displacing oxygen and thus promoting the deoxy state B) CO2 displaces BPG, thus promoting the oxy state + C) CO 2 is converted to bicarbonate and H which promotes the oxy state + D) CO 2 is converted to bicarbonate and H which promotes the deoxy state E) none of the above Answer: D Difficulty: Hard Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin

18) Which allosteric effector has the greatest ability to stabilize the deoxy state of hemoglobin?

A) BPG B) CO2 C) O2 D) H+ E) all of the above have equal ability Answer: A Difficulty: Medium Section Reference: 5-1 Learning Objective: Compare the structures, oxygen-binding activity, and biological functions of myoglobin and hemoglobin 19) Which of the following fibers is correctly paired with the protein that forms the fiber?

A) microfilaments: actin B) microtubule: tubulin C) extracellular support fibers: collagen D) intermediate filaments: keratin E) all of the above Answer: E Difficulty: Medium Section Reference: 5-2 Learning Objective: Relate the structures of fibrous proteins to their functions

20) During the formation of microfilaments, which of the following occurs?

A) ATP binds to F-actin B) F-actin polymerizes, becoming G-actin C) ATP hydrolysis is catalyzed by F-actin D) polymerization proceeds quickly at first, then slows after about ten actin monomers have polymerized E) none of the above Answer: C Difficulty: Medium Section Reference: 5-2 Learning Objective: Relate the structures of fibrous proteins to their functions

21) When a cell moves along a surface, actin _____ occurs at the leading edge while _____ occurs at the trailing edge A) polymerization; depolymerization B) depolymerization; polymerization C) denaturation; renaturation D) renaturation; denaturation E) none of the above Answer: A Difficulty: Medium Section Reference: 5-2 Learning Objective: Relate the structures of fibrous proteins to their functions 22) Which of the following details the nucleotide-binding site when tubulin dimers assemble into microtubules?

A) both  and  sites are bound to GTP B) the  site is bound to GTP; the  site is bound to GDP C) the  site is bound to GDP; the  site is bound to GTP D) both  and  sites are bound to GDP E) the  site is bound to GTP; the  site is unoccupied following GTP hydrolysis and release of GDP Answer: B

Difficulty: Hard Section Reference: 5-2 Learning Objective: Relate the structures of fibrous proteins to their functions 23) Which of the following explains how cell division is blocked by drugs that prevent proper microtubule function?

A) the condensation of chromatin requires a microtubule skeleton B) production of new membranes for organelles and nucleus requires microtubules C) chromosomes separate along a microtubule spindle D) division of organelles between daughter cells requires organelle movement along microtubules E) none of the above Answer: C Difficulty: Medium Section Reference: 5-2 Learning Objective: Relate the structures of fibrous proteins to their functions

24) What is the most prevalent secondary structure observed in the proteins of intermediate filaments?

A) -helices B) -helices C) -sheets D) -sheets E) both -helices and -helices are observed Answer: A Difficulty: Easy Section Reference: 5-2 Learning Objective: Relate the structures of fibrous proteins to their functions 25) Which amino acid is critical for crosslinking of keratin fibers?

A) Ser B) Lys C) His D) Cys E) Gln

Answer: D Difficulty: Easy Section Reference: 5-2 Learning Objective: Relate the structures of fibrous proteins to their functions 26) During the initial synthesis of collagen molecules, _____ and _____ are most often incorporated into the growing protein.

A) Ser; Gly B) Pro; Ala C) Gly; Pro D) Ala; Gly E) Ser; Pro Answer: C Difficulty: Easy Section Reference: 5-2 Learning Objective: Relate the structures of fibrous proteins to their functions 27) Ascorbic acid is required for the production of _____ in collagen.

A) hydroxylysine B) -carboxyglutamic acid C) desmosine D) aspartate -semialdehyde E) hydroxyproline Answer: E Difficulty: Easy Section Reference: 5-2 Learning Objective: Relate the structures of fibrous proteins to their functions 28) The helical structure of collagen contains _____.

A) three right-handed helices wound around each other in a right-handed triple helix B) three right-handed helices wound around each other in a left-handed triple helix C) three left-handed helices wound around each other in a left-handed triple helix D) three left-handed helices wound around each other in a right-handed triple helix E) none of the above

Answer: D Difficulty: Medium Section Reference: 5-2 Learning Objective: Relate the structures of fibrous proteins to their functions

29) Which amino acid is critical for crosslinking of collagen trimers?

A) Ser B) Lys C) His D) Cys E) Gln Answer: B Difficulty: Easy Section Reference: 5-2 Learning Objective: Relate the structures of fibrous proteins to their functions

30) Bone and tendons contain _____ while hair and nails contain _____.

A) collagen; keratin B) actin; keratin C) tubulin; collagen D) collagen; actin E) tubulin; keratin Answer: A Difficulty: Easy Section Reference: 5-2 Learning Objective: Relate the structures of fibrous proteins to their functions

31) In a muscle cell, what is the name for the bundles of myosin tails?

A) cytoskeleton B) thick filaments C) intermediate filaments D) thin filaments E) none of the above Answer: B

Difficulty: Easy Section Reference: 5-3 Learning Objective: Describe how motor proteins operate 32) Each myosin head contains a binding site for _____ and a binding site for _____.

A) tubulin; GTP B) another myosin molecule; ATP C) kinesin; GTP D) actin; ATP E) none of the above Answer: D Difficulty: Medium Section Reference: 5-3 Learning Objective: Describe how motor proteins operate 33) Which of the following correctly describes the sequence of events in the myosin-actin cycle?

A) myosin release from actin, ATP binds to myosin, myosin binds to another actin subunit, release of Pi and ADP, stretched myosin returns to original conformation B) myosin release from actin, ATP binds to myosin, myosin binds to another actin subunit, stretched myosin returns to original conformation, release of Pi and ADP C) ATP binds to myosin, myosin release from actin, myosin binds to another actin subunit, release of Pi and ADP, stretched myosin returns to original conformation D) ATP binds to myosin, myosin release from actin, myosin binds to another actin subunit, stretched myosin returns to original conformation, release of Pi and ADP E) myosin release from actin, myosin binds to another actin subunit, ATP binds to myosin, stretched myosin returns to original conformation, release of Pi and ADP Answer: C Difficulty: Hard Section Reference: 5-3 Learning Objective: Describe how motor proteins operate 34) Each kinesin head contains a binding site for _____ and a binding site for _____.

A) tubulin; GTP B) another kinesin molecule; GTP C) myosin; ATP

D) actin; ATP E) tubulin; ATP Answer: E Difficulty: Medium Section Reference: 5-3 Learning Objective: Describe how motor proteins operate

35) The heads of kinesin bind to _____; the light chains of kinesin bind to _____.

A) tubulin; proteins in the membrane of a vesicle B) proteins in the membrane of an organelle; tubulin C) proteins in the membrane of a vesicle; actin D) collagen fibers; proteins in the cell membrane E) none of the above Answer: A Difficulty: Medium Section Reference: 5-3 Learning Objective: Describe how motor proteins operate 36) Which of the following correctly describes the sequence of events in the kinesin reaction cycle? For simplicity, the two heads are referred to as head 1 and head 2. Head 1 starts as the leading head.

A) head 1 releases tubulin, ATP binds to head 1, head 2 swings forward, head 2 binds to tubulin, ADP release from head 2, ATP hydrolysis in head 1 B) ATP binds to head 1, head 2 swings forward, ADP release from head 2, ATP hydrolysis in head 1, head 2 binds to tubulin, head 1 releases tubulin C) ATP binds to head 1, head 2 swings forward, head 2 binds to tubulin, ATP hydrolysis in head 1, ADP release from head 2, head 1 releases tubulin D) ATP binds to head 1, head 2 swings forward, head 2 binds to tubulin, ADP release from head 2, ATP hydrolysis in head 1, head 1 releases tubulin E) none of the above Answer: D Difficulty: Hard Section Reference: 5-3 Learning Objective: Describe how motor proteins operate

37) Which of the following represents the longest distance traveled by a kinesin-vesicle complex?

A) movement of a mitochondria in a cardiac cell B) movement of a neurotransmitter vesicle down the axon of a nerve cell C) movement of a glucose filled vesicle to the membrane of a liver cell D) movement of a lipid-filled vesicle within an intestinal cell E) none of the above Answer: B Difficulty: Medium Section Reference: 5-3 Learning Objective: Describe how motor proteins operate

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 6 Question type: Multiple Choice 1) Different enzymes that catalyze the same reaction are known as _____. A) transferases B) isomerases C) allosteric enzymes D) holoenzymes E) isozymes Answer: E Difficulty: Easy Section Reference: 6-1 Learning Objective: Explain how enzymes differ from other catalysts 2) An uncatalyzed reaction has a rate of 4.2 x 10–7 sec–1. When an enzyme is added the rate is 3.2 x 104 sec–1. Calculate the rate enhancement caused by the enzyme. A) 7.6 x 1010 B) 3.2 x 104 C) 1.3 x 10–2 D) 7.4 x 10–3 E) cannot be determined Answer: A Difficulty: Medium Section Reference: 6-1 Learning Objective: Explain how enzymes differ from other catalysts

3) Which of the following is the most effective way to increase the rate of a biochemical reaction?

A) increase the temperature B) increase the concentrations of the reactants C) increase or decrease the pH D) add a catalyst E) none of the above

Answer: D Difficulty: Easy Section Reference: 6-1 Learning Objective: Explain how enzymes differ from other catalysts

4) Chymotrypsin catalyzes the hydrolysis of a peptide bond and is therefore categorized as a _____.

A) oxidoreductase B) transferase C) hydrolase D) lyase E) ligase Answer: C Difficulty: Medium Section Reference: 6-1 Learning Objective: Explain how enzymes differ from other catalysts

5) The ability for an enzyme to pick out one particular substrate from the myriad of molecules floating around its environment is an example of _____.

A) natural selection B) specificity C) high affinity D) processivity E) none of the above Answer: B Difficulty: Easy Section Reference: 6-1 Learning Objective: Explain how enzymes differ from other catalysts

6) The highest point in a reaction coordinate diagram represents _____.

A) an intermediate of the reaction pathway B) the reactants in an exergonic reaction C) the products in an endergonic reaction D) the transition state

E) the overall G for the reaction Answer: D Difficulty: Easy Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions

7) How does a catalyst affect the overall G of an endergonic reaction?

A) it has no effect B) the reaction becomes more endergonic

C) the reaction has a G of zero

D) the reaction becomes exergonic E) none of the above Answer: A Difficulty: Easy Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions 8) How does a catalyst increase the rate of a reaction?

A) it makes the reaction more exergonic B) it increases the temperature of the reaction C) it allows reacting molecules to more easily form the transition state D) it causes a localized increase in the concentration of reactants E) none of the above Answer: C Difficulty: Medium Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions 9) An organic molecule that is tightly bound to an enzyme and participates in an enzyme catalyzed reaction is specifically referred to as a _____.

A) cofactor B) metal ion C) coenzyme D) cosubstrate

E) prosthetic group Answer: E Difficulty: Easy Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions 10) An enzyme that forms a covalent bond with its substrate during the course of a reaction is considered to undergo _____.

A) acid-base catalysis B) covalent catalysis C) electrophilic catalysis D) metal ion catalysis E) none of the above Answer: B Difficulty: Easy Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions 11) Which of the following amino acids would be most likely found in the active site of an enzyme that uses acid-base catalysis?

A) Asn B) Ser C) Met D) His E) Trp Answer: D Difficulty: Medium Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions 12) Which of the following is seen in a reaction coordinate diagram for an enzyme-catalyzed reaction that uses covalent catalysis?

A) an intermediate B) two distinct transition states

C) reactants that are lower in energy than an intermediate D) products that are lower in energy than an intermediate E) all of the above Answer: E Difficulty: Medium Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions

13) In the enzyme catalyzed decarboxylation of acetoacetate, a Schiff base is formed between the ketone of acetoacetate and a _____ residue in the active site of the enzyme.

A) Arg B) Asn C) Lys D) Glu E) Ser Answer: C Difficulty: Medium Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions

14) Of the following ions, which would be most likely to participate in metal ion catalysis?

A) Na+ B) Zn2+ C) Ag+ D) K+ E) Ba2+ Answer: B Difficulty: Medium Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions

15) In an enzyme mechanism that generates a negative charge in the transition state, which of the following would be most effective to have in the active site of the enzyme?

A) transition metal cation

B) Asp residue C) Gln residue D) transition metal anion E) none of the above Answer: A Difficulty: Medium Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions

16) What three amino acids are found in the catalytic triad of chymotrypsin? A) Glu, His, Thr B) Ser, Arg, Cys C) Asp, His, Ser D) Cys, Lys, Glu E) Asn, His, Thr Answer: C Difficulty: Easy Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions

17) What amino acid performs the nucleophilic attack during the chymotrypsin mechanism?

A) Ser B) His C) Lys D) Cys E) Thr Answer: A Difficulty: Easy Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions

18) During the first half of the chymotrypsin mechanism where the acyl-enzyme intermediate is formed, what role does His play?

A) general acid only

B) general base only C) general acid then general base D) general base then general acid E) nucleophile Answer: D Difficulty: Hard Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions

19) If the Asp in the chymotrypsin active site was mutated to another amino acid, which of the following would be considered an invisible mutation in that it is least likely to impact the function of the enzyme?

A) Asp → Asn B) Asp → Glu C) Asp → His D) Asp → Ser E) Asp → Lys Answer: B Difficulty: Medium Section Reference: 6-2 Learning Objective: List the chemical mechanisms enzymes use to accelerate reactions 20) Of all the species that enzymes bind, they are thought to bind most tightly to _____.

A) substrates B) products C) transition states D) intermediates E) all are bound very tightly Answer: C Difficulty: Easy Section Reference: 6-3 Learning Objective: Describe how enzymes stabilize transition states 21) In the chymotrypsin mechanism, what is used to stabilize the negative charge on the carbonyl oxygen of the transition state?

A) hydrogen bonding between the enzyme and the anion from the carbonyl oxygen B) electrostatic interaction of the positively charged His and carbonyl oxygen C) electrostatic interaction of the negatively charged Asp and carbonyl oxygen D) electrostatic interaction of the active site Zn2+ and carbonyl oxygen E) all of the above Answer: A Difficulty: Medium Section Reference: 6-3 Learning Objective: Describe how enzymes stabilize transition states

22) If an enzyme rate increases 10-fold for every 5.7 kJ/mol decrease in the energy of activation, what rate increase would be observed if three H-bonds were stabilizing the transition state with each H-bond having a strength of 21 kJ/mol? A) 11-fold increase B) 37-fold increase C) 60-fold increase D) 100-fold increase E) 1011-fold increase Answer: E Difficulty: Hard Section Reference: 6-3 Learning Objective: Describe how enzymes stabilize transition states

23) When the transition state is formed, what is the specific interaction observed between Asp and His that helps stabilize the transition state?

A) dipole-dipole interaction B) electrostatic interaction C) hydrogen bond D) low-barrier hydrogen bond E) covalent bond Answer: D Difficulty: Medium Section Reference: 6-3 Learning Objective: Describe how enzymes stabilize transition states

24) The ability for an enzyme to change its shape upon substrate binding represents the concept of _____. A) lock and key B) induced fit C) proximity and orientation effects D) covalent catalysis E) none of the above Answer: B Difficulty: Easy Section Reference: 6-3 Learning Objective: Describe how enzymes stabilize transition states

25) The enzyme hexokinase catalyzes a reaction where its substrates are completely sequestered from the aqueous environment allowing for interactions to occur between enzyme and substrates that would not normally occur in an aqueous environment. What term describes this type of catalysis?

A) electrostatic catalysis B) desolvation catalysis C) non-aqueous catalysis D) hydrogen-bonded catalysis E) closed-system catalysis Answer: A Difficulty: Medium Section Reference: 6-3 Learning Objective: Describe how enzymes stabilize transition states

26) Chymotrypsin catalyzes the hydrolysis of peptide bonds adjacent to _____ residues in a peptide.

A) neutral polar B) nonpolar C) negatively charged D) positively charged E) all of the above since chymotrypsin has little substrate specificity Answer: B

Difficulty: Medium Section Reference: 6-3 Learning Objective: Describe how enzymes stabilize transition states 27) What amino acid residue present in the specificity pocket allows trypsin to bind to peptides containing Arg or Lys? A) Ser B) His C) Lys D) Val E) Asp Answer: E Difficulty: Easy Section Reference: 6-4 Learning Objective: Explain how enzymes may be activated and inhibited 28) Chymotrypsin has a large specificity pocket to bind the aromatic amino acids while elastase has a very small specificity pocket meant to bind Ala or Gly. Which of the following amino acid substitutions changes the specificity pocket of chymotrypsin to that of elastase?

A) Trp → Ser B) Leu → Ala C) Gly → Val D) Lys → Asp E) Val → Asn Answer: C Difficulty: Medium Section Reference: 6-4 Learning Objective: Explain how enzymes may be activated and inhibited 29) The molecule chymotrypsinogen is known as a(n) _____.

A) apoenzyme B) holoenzyme C) protease inhibitor D) zymogen E) none of the above

Answer: D Difficulty: Easy Section Reference: 6-4 Learning Objective: Explain how enzymes may be activated and inhibited

30) Which protein in the blood is responsible for converting fibrinogen to fibrin?

A) thrombin B) factor X C) factor VII D) factor VIIa E) prothrombin Answer: A Difficulty: Easy Section Reference: 6-4 Learning Objective: Explain how enzymes may be activated and inhibited

31) Conversion of factor X to factor Xa represents a(n) _____ form of activation; binding of antithrombin to thrombin represents a(n) _____ form of inhibition. A) reversible; reversible B) irreversible; reversible C) reversible; irreversible D) irreversible; irreversible E) none of the above since antithrombin is not an inhibitor of thrombin Answer: B Difficulty: Medium Section Reference: 6-4 Learning Objective: Explain how enzymes may be activated and inhibited

32) Which of the following is true regarding heparin?

A) it is an allosteric activator of antithrombin B) it is a sulfated polysaccharide C) it simultaneously binds to antithrombin and the target of antithrombin D) it is used clinically as an anticoagulant E) all of the above

Answer: E Difficulty: Hard Section Reference: 6-4 Learning Objective: Explain how enzymes may be activated and inhibited

33) Zymogens are not enzymatically active because _____.

A) they do not contain the cofactors required for catalysis B) they are the product of mutated genes C) their active sites are distorted and incapable of enzymatic activity D) the pH of their environment is not optimal for activity E) none of the above Answer: C Difficulty: Medium Section Reference: 6-4 Learning Objective: Explain how enzymes may be activated and inhibited

34) Which of the following is a feature of protease inhibitor specific for trypsin?

A) contains a positive charge to mimic the charge of the substrate B) ability to interact with the Ser of the catalytic triad C) inability to form the tetrahedral intermediate D) high affinity for the enzyme active site E) all of the above Answer: E Difficulty: Hard Section Reference: 6-4 Learning Objective: Explain how enzymes may be activated and inhibited

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 7 Question type: Multiple Choice 1) Which of the following is true about enzymes?

A) enzymes show very little specificity for their substrates B) enzymes catalyze reactions in only one direction C) enzyme activities can often be regulated D) enzymes reaction rates are generally slower than other chemical catalysts E) enzymes operate under a wide range of temperatures and pH Answer: C Difficulty: Medium Section Reference: 7-1 Learning Objective: Explain why an enzyme’s activity varies with substrate concentration

2) A plot of velocity versus substrate concentration for a simple enzyme-catalyzed reaction produces a _____. This indicates that at some point, the enzyme is _____.

A) straight line; inhibited by product B) hyperbolic curve; saturated with substrate C) sigmoidal curve; inhibited by substrate D) hyperbolic curve; activated by substrate E) sigmoidal curve; saturated with substrate Answer: B Difficulty: Medium Section Reference: 7-1 Learning Objective: Explain why an enzyme’s activity varies with substrate concentration

3) When a substrate and enzyme interact, the first chemical species formed is _____.

A) enzyme-substrate complex B) enzyme-transition state complex C) enzyme-product complex D) enzyme plus product E) none of the above

Answer: A Difficulty: Easy Section Reference: 7-1 Learning Objective: Explain why an enzyme’s activity varies with substrate concentration 4) How is an enzyme-catalyzed reaction affected by the addition of more enzyme?

A) velocity is not effected B) velocity will increase only if more substrate is also added C) velocity will increase D) velocity will decrease E) none of the above Answer: C Difficulty: Easy Section Reference: 7-1 Learning Objective: Explain why an enzyme’s activity varies with substrate concentration 5) For a reaction A + B → C, if [B] is much larger than [A] so that [B] essentially remains constant over the course of the reaction, the kinetics will be _____.

A) zero-order B) hyperbolic C) first-order D) sigmoidal E) pseudo first-order Answer: E Difficulty: Hard Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 6) Which of the following expresses the velocity for an enzyme-catalyzed reaction that obeys Michaelis-Menten kinetics?

A) v = k1[E][S] B) v = k1[E][S] - k-1[ES] C) v = k1[E][S] + k2[ES] D) v = k2[ES]

E) v = k2[ES] - k-1[ES] Answer: D Difficulty: Hard Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 7) Which of the following must be true if the steady state assumption is to be used?

A) [E]T = [ES] B) (k2 - k-1) / k1 = 1 C) k1[E][S] = k2[ES] D) k1[E][S] = k2[ES] - k-1[ES] E) d[ES] / dt = 0 Answer: E Difficulty: Hard Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 8) The Michaelis constant is defined as _____.

A) KM = k2 / k1 B) KM = (k2 + k-1) / k1 C) KM = (k2 - k-1) / k1 D) KM = (k2 + k1) / k-1 E) KM = (k2 - k1) / k-1 Answer: B Difficulty: Medium Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 9) Which of the following properly expresses the Michaelis-Menten equation?

A) vo = Vmax [S] / (KM + [S]) B) vo = Vmax KM / (KM + [S]) C) kcat = Vmax / [E]T D) Vmax = vo [S] / (KM + [S]) E) Vmax = vo KM / (KM + [S])

Answer: A Difficulty: Medium Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 10) When is KM considered to be the same as the dissociation constant for the ES complex i.e., KM  [E] [S] / [ES].

A) ES → E + P is fast compared to ES → E + S B) the turnover number is very large C) kcat/KM is near the diffusion-controlled limit D) k2 << k-1 E) KM can never be the same as the dissociation constant Answer: D Difficulty: Hard Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 11) What percentage of Vmax is obtained when the substrate is present at ¼ of the KM? ` A) 5% B) 20% C) 25% D) 80% E) 100% Answer: B Difficulty: Medium Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 12) If an enzyme-catalyzed reaction has a velocity of 2 mM/min and a Vmax of 10 mM/min when the substrate concentration is 0.5 mM, what is the KM? A) 0.2 mM B) 0.5 mM C) 1 mM D) 2 mM

E) 5 mM Answer: D Difficulty: Medium Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 13) Which of the following must be true for an enzymatic reaction obeying the MichaelisMenten equation to reach 3/4 of its maximum velocity?

A) [S] must be ¾KM B) [S] must be 1.5KM C) [S] must be 2KM D) [S] must be 3KM E) [S] must be 4KM Answer: D Difficulty: Hard Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 14) If an enzyme-catalyzed reaction with a KM of 3.5 mM has a velocity of 5 mM/min at a substrate concentration of 0.5 mM, what is the Vmax?

A) 0.625 mM/min B) 15 mM/min C) 17.5 mM/min D) 35 mM/min E) 40 mM/min Answer: E Difficulty: Hard Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 15) What is the kcat for a reaction in which Vmax is 0.4 mmoles/min and the reaction mixture contains 5  10-6 micromoles of enzyme?

A) 2 x 10-14 min-1 B) 2 x 10-11 min-1

C) 8 x 107 min-1 D) 4 x 108 min-1 E) 8 x 109 min-1 Answer: C Difficulty: Hard Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation

16) The catalytic constant, or kcat, is also known as the _____.

A) turnover number B) saturation number C) catalytic efficiency number D) diffusion number E) Menten number Answer: A Difficulty: Easy Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 17) Which of the following indicates that an enzyme has evolved to its most efficient form?

A) kcat is a large number B) KM is a small number C) KM is a large number D) kcat/KM is a small number E) kcat/KM is near the diffusion-controlled limit Answer: E Difficulty: Medium Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 18) An extremely efficient enzyme has a _____ KM and a _____ kcat.

A) small; small B) small; large C) large; large

D) large; small E) kcat and KM do nothing to predict the efficiency of an enzyme Answer: B Difficulty: Medium Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation

19) A Lineweaver-Burk plot is a _____.

A) double reciprocal plot B) Michaelis-Menten plot C) sigmoidal plot D) hyperbolic plot E) logarithmic plot Answer: A Difficulty: Easy Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 20) If a Lineweaver-Burk plot gave a line with an equation of y = 0.490 x + 0.059, what is the velocity at a substrate concentration of 5 mM? The original units for substrate were in mM and velocity in mM/s.

A) 0.288 mM/s B) 0.399 mM/s C) 2.51 mM/s D) 6.37 mM/s E) the velocity cannot be determined from this data Answer: D Difficulty: Hard Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation 21) If a Lineweaver-Burk plot gave a line with an equation of y = 0.25 x + 0.34, what are the values of KM and Vmax if the substrate concentration is in mM and the velocity in mM/s?

A) 0.085 mM and 0.34 mM/s

B) 2.9 mM and 0.023 mM/s C) 0.74 mM and 2.9 mM/s D) 0.37 mM and 1.4 mM/s E) 1.35 mM and .034 mM/s Answer: C Difficulty: Hard Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation

22) Which of the following types of enzyme-catalyzed reactions follows non-Michaelis-Menten kinetics?

A) bisubstrate reactions with a random mechanism B) bisubstrate reactions with a ping pong mechanism C) bisubstrate reactions with an ordered mechanism D) allosteric enzyme reactions E) all of the above Answer: E Difficulty: Easy Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation

23) In a bisubstrate reaction, reactant A binds, followed by reactant B which then get converted to products C and D. An experiment showed that B cannot bind without A having bound first. What mechanism is indicated by this data? A) ordered mechanism B) random mechanism C) ping pong mechanism D) cooperative mechanism E) none of the above Answer: A Difficulty: Medium Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation

24) In a bisubstrate reaction, reactant A binds and is then converted to product C. Next, reactant

B binds and is then converted to product D. An experiment showed that B cannot bind without C being released first. What mechanism is indicated by this data? A) ordered mechanism B) random mechanism C) ping pong mechanism D) cooperative mechanism E) none of the above Answer: C Difficulty: Hard Section Reference: 7-2 Learning Objective: Define the terms of the Michaelis–Menten equation

25) Some irreversible inhibitors are called _____ because they bind to the active site of the enzyme and begin the catalytic process, just like a normal substrate.

A) irreversible substrates B) suicide substrates C) noncompetitive substrates D) ping pong substrates E) allosteric substrates Answer: B Difficulty: Easy Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics

26) An inhibitor that binds to the active site only in the absence of the substrate and in a reversible fashion is a(n) _____.

A) allosteric inhibitor B) suicide substrate C) mixed inhibitor D) noncompetitive inhibitor E) competitive inhibitor Answer: E Difficulty: Easy Section Reference: 7-3

Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics 27) How are the kinetics of an enzyme-catalyzed reaction affected by a competitive inhibitor?

A) Vmax decreased, KM increased B) Vmax decreased, KM decreased C) Vmax decreased, KM unchanged D) Vmax unchanged, KM increased E) Vmax unchanged, KM decreased Answer: D Difficulty: Medium Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics 28) If a Lineweaver-Burk plot was made for an enzyme-catalyzed reaction, both with and without a competitive inhibitor present, what difference would be seen?

A) the y-intercept would be lower for the inhibited reaction B) the y-intercept would be higher for the inhibited reaction C) the slope would be less for the inhibited reaction D) the slope would be greater for the inhibited reaction E) none of the above Answer: C Difficulty: Hard Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics 29) What type of inhibition explains why even at very high substrate concentrations, enzyme activity will decrease as time increases?

A) allosteric inhibition B) product inhibition C) transition state analogs D) irreversible inhibition E) uncompetitive inhibition

Answer: B Difficulty: Medium Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics 30) What does the KI for a competitive inhibitor mean?

A) higher KI values mean tighter binding to ES complex B) lower KI values mean tighter binding to ES complex C) higher KI values mean tighter binding to the enzyme D) lower KI values mean tighter binding to the enzyme E) KI values tell nothing about inhibitor binding Answer: D Difficulty: Medium Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics 31) Which of the following is true regarding transition state analogs?

A) they are competitive inhibitors B) they bind to an active site with much higher affinity than most inhibitors C) they are much more stable than the transition state D) their affinity for an enzyme is often much greater that the substrate E) all of the above Answer: E Difficulty: Medium Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics 32) A reversible inhibitor that binds to a site other than the active site regardless of whether or not the substrate is bound is a _____.

A) noncompetitive inhibitor B) competitive inhibitor C) uncompetitive inhibitor

D) allosteric inhibitor E) suicide substrate Answer: A Difficulty: Easy Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics

33) How are the kinetics of an enzyme-catalyzed reaction affected by a purely noncompetitive inhibitor?

A) Vmax decreased, KM increased B) Vmax decreased, KM decreased C) Vmax decreased, KM unchanged D) Vmax unchanged, KM increased E) Vmax unchanged, KM decreased Answer: C Difficulty: Medium Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics 34) If a Lineweaver-Burk plot was made for an enzyme-catalyzed reaction, both with and without a noncompetitive inhibitor present, what difference would be seen?

A) the y-intercept would be higher with slope unchanged for the inhibited reaction B) the y-intercept would be lower with larger slope for the inhibited reaction C) the y-intercept would be lower with smaller slope for the inhibited reaction D) the y-intercept would be higher with larger slope for the inhibited reaction E) the y-intercept would be higher with smaller slope for the inhibited reaction Answer: D Difficulty: Hard Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics 35) How are the kinetics of an enzyme-catalyzed reaction affected by a mixed inhibitor?

A) Vmax decreased, KM increased or decreased B) Vmax decreased, KM decreased C) Vmax decreased, KM increased D) Vmax unchanged, KM increased E) Vmax unchanged, KM increased or decreased Answer: A Difficulty: Hard Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics

36) A reversible inhibitor that only affects multisubstrate enzymes and binds to the enzyme only after one substrate has bound is a _____.

A) noncompetitive inhibitor B) uncompetitive inhibitor C) competitive inhibitor D) allosteric inhibitor E) suicide substrate Answer: B Difficulty: Medium Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics 37) Which of the following types of inhibition can be reversed by addition of more substrate?

A) noncompetitive inhibition B) competitive inhibition C) uncompetitive inhibition D) irreversible inhibition E) none of the above Answer: B Difficulty: Easy Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics

38) Which of the following statements regarding allosteric enzymes is true?

A) they are always oligomeric B) they are generally found at regulatory sites in metabolic pathways C) they are subject to regulation by both positive and negative effectors D) a plot of velocity versus [substrate] often yields a sigmoidal curve E) all of the above Answer: E Difficulty: Medium Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics 39) Which of the following represents a rapid and reversible mechanism to alter the activity of an enzyme?

A) synthesis of more enzyme to increase activity B) degradation of enzyme to decrease activity C) covalent attachment of a phosphate group to increase or decrease activity D) movement of an enzyme from one cellular compartment to another E) none of the above Answer: C Difficulty: Medium Section Reference: 7-3 Learning Objective: Distinguish the effects of different types of enzyme inhibitors on enzyme kinetics

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 8 Question type: Multiple Choice 1) What are the characteristics of most unsaturated fatty acids found within a human cell?

A) protonated carboxylic acid and trans double bonds B) deprotonated carboxylic acid and trans double bonds C) protonated carboxylic acid and cis double bonds D) deprotonated carboxylic acid and cis double bonds E) none of the above Answer: D Difficulty: Easy Section Reference: 8-1 Learning Objective: Recognize the physical characteristics of lipids

2) Which of the following is considered an omega-3 fatty acid?

A) 9,12-Octadecadienoic acid B) 9,12,15-Octadecatrienoic acid C) 6,9,12-Octadecatrienoic acid D) 8,11,14-Eicosatrienoic acid E) 5,8,11,14-Eicosatetraenoic acid Answer: B Difficulty: Medium Section Reference: 8-1 Learning Objective: Recognize the physical characteristics of lipids

3) The major lipid component of cell membranes are _____.

A) triacylglycerols B) cholesterol C) glycerophospholipids D) plasmologens E) gangliosides

Answer: C Difficulty: Easy Section Reference: 8-1 Learning Objective: Recognize the physical characteristics of lipids

4) Which of the following alcohols is esterified to the phosphate group of glycerophospholipids?

A) choline B) ethanolamine C) glycerol D) serine E) all of the above Answer: E Difficulty: Medium Section Reference: 8-1 Learning Objective: Recognize the physical characteristics of lipids

5) The most notable difference between _____ and other lipids is the presence of four fused rings.

A) cholesterol B) arachidonic acid C) gangliosides D) plasmologens E) triacylglycerols Answer: A Difficulty: Easy Section Reference: 8-1 Learning Objective: Recognize the physical characteristics of lipids

6) Which of the following terms describes all glycerophospholipid?

A) zwitterionic B) amphipathic C) nonpolar D) amphoteric E) none of the above

Answer: B Difficulty: Medium Section Reference: 8-1 Learning Objective: Recognize the physical characteristics of lipids

7) Which of the following is the primary building block for the synthesis of molecules like cholesterol or ubiquinone?

A) acetyl-CoA B) palmitic acid C) choline D) isoprene E) sphingosine Answer: D Difficulty: Medium Section Reference: 8-1 Learning Objective: Recognize the physical characteristics of lipids

8) A type of lipid that commonly forms a waterproof barrier and is composed of a fatty acid and a fatty alcohol is called a _____.

A) terpenoid B) ganglioside C) capsaicin D) steroid E) wax Answer: E Difficulty: Easy Section Reference: 8-1 Learning Objective: Recognize the physical characteristics of lipids

9) Which of the following vitamins is derived from cholesterol?

A) vitamin A B) vitamin D C) vitamin E D) vitamin K E) none of the above

Answer: B Difficulty: Medium Section Reference: 8-1 Learning Objective: Recognize the physical characteristics of lipids

10) What two molecules are used in the synthesis of sphingosine?

A) arachidonic acid and serine B) stearic acid and isoprene C) palmitic acid and choline D) linoleic acid and isoprene E) palmitic acid and serine Answer: E Difficulty: Medium Section Reference: 8-1 Learning Objective: Recognize the physical characteristics of lipids

11) Which of the following explains why free fatty acids do not form bilayers?

A) the width of the polar head is greater than the nonpolar tail B) the width of the polar head is less than the nonpolar tail C) the width of the polar head is equal to the nonpolar tail D) the width of the nonpolar head is greater than the polar tail E) the width of the nonpolar head is less than the polar tail Answer: A Difficulty: Medium Section Reference: 8-2 Learning Objective: Describe the properties of the lipid bilayer

12) As temperatures grow colder with the onset of winter, animals will adapt by changing the fatty acid composition of cell membranes. What characteristics of fatty acids will be seen?

A) longer chains with greater unsaturation B) longer chains with greater saturation C) shorter chains with greater unsaturation D) shorter chains with greater saturation E) chain length and saturation do not change in a cell membrane

Answer: C Difficulty: Medium Section Reference: 8-2 Learning Objective: Describe the properties of the lipid bilayer 13) A membrane raft is a(n) _____ in the lipid bilayer of a cell membrane.

A) transmembrane protein B) integral membrane protein oriented to the intracellular side C) integral membrane protein oriented to the extracellular side D) region of high cholesterol and sphingolipid content E) none of the above Answer: D Difficulty: Medium Section Reference: 8-2 Learning Objective: Describe the properties of the lipid bilayer 14) Which of the following is true regarding membrane asymmetry?

A) transverse diffusion occurs very quickly B) lateral diffusion occurs very slowly C) a flippase causes lateral diffusion to occur very rapidly D) carbohydrates attached to membrane lipids are usually found on the cytosolic side of the membrane E) none of the above Answer: E Difficulty: Medium Section Reference: 8-2 Learning Objective: Describe the properties of the lipid bilayer

15) In an -helical protein that spans a cell membrane, _____ would likely be in the center of the membrane while _____ would likely be associated with the polar head groups and _____ would likely be associated with the aqueous environment A) Trp; Asn; Ala B) Leu; Gln; Asp C) Tyr; Glu; Gly

D) Ile; Arg; Gln E) Val; Ser; Thr Answer: B Difficulty: Hard Section Reference: 8-3 Learning Objective: Explain how proteins associate with membranes 16) Which of the following statements describes integral membrane proteins?

A) they never completely span the lipid bilayer B) they are easily removed by changes in pH or high salt C) amino acids that contact the core of the membrane are hydrophobic D) they tend to be water soluble E) their association with the membrane is through an attached fatty acyl or prenyl group Answer: C Difficulty: Medium Section Reference: 8-3 Learning Objective: Explain how proteins associate with membranes 17) If a transmembrane domain of protein contains -sheet structure, the overall structure of the transmembrane portion is likely a ____________.

A) -barrel B) -tube C) -turn D) -helix E) none of the above Answer: A Difficulty: Easy Section Reference: 8-3 Learning Objective: Explain how proteins associate with membranes

18) Which fatty acid is commonly attached to proteins to allow membrane localization?

A) eicosapentaenoic acid (EPA) B) arachidonic acid C) linoleic acid

D) myristic acid E) farnesylic acid Answer: D Difficulty: Medium Section Reference: 8-3 Learning Objective: Explain how proteins associate with membranes

19) If polar amino acids are found in a membrane spanning -helical region, they are most likely _____.

A) mutations B) modified with nonpolar groups by prenylation, methylation and/or acylation C) hydrogen-bonded to other polar amino acids to prevent interaction with the membrane lipids D) hydrogen-bonded with hydroxyl groups of the membrane fatty acids E) none of the above Answer: C Difficulty: Hard Section Reference: 8-3 Learning Objective: Explain how proteins associate with membranes

20) Which of the following is a characteristic of integral membrane proteins?

A) most of their movement is by lateral diffusion B) transverse diffusion occurs often but rather slowly C) interactions between proteins makes the membrane highly rigid D) all have carbohydrates attached to the extracellular domain E) none of the above Answer: A Difficulty: Medium Section Reference: 8-4 Learning Objective: Summarize the features of the fluid mosaic model 21) The carbohydrate portion of a membrane spanning glycoprotein is found _____.

A) spanning the membrane B) on both the cytoplasmic and extracellular sides of the membrane C) only on the cytoplasmic side of the membrane

D) only on the extracellular side of the membrane E) carbohydrates are not found on membrane spanning glycoproteins Answer: D Difficulty: Medium Section Reference: 8-4 Learning Objective: Summarize the features of the fluid mosaic model

22) Which of the following aspects of membrane protein movement is explained by the fluid mosaic model?

A) proteins that are immobile are often esterified to cholesterol via an Asp residue B) proteins that are mobile only in a small area are sequestered by proteins attached to the cytoskeleton C) proteins that freely diffuse through the membrane often undergo flip-flopping D) proteins confined to a lipid raft are linked to phosphatidylserine via and amide bond E) none of the above Answer: B Difficulty: Hard Section Reference: 8-4 Learning Objective: Summarize the features of the fluid mosaic model

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 9 Question type: Multiple Choice 1) What is the membrane potential created by a sodium gradient where [Na+]out = 145 mM and [Na+]in = 12mM at 37 C? A) 67 mV B) 7.9 mV C) -7.9 mV D) -29 mV E) -67 mV Answer: E Difficulty: Hard Section Reference: 9-1 Learning Objective: Analyze the thermodynamics of solute movement across membranes + 2) What is the ratio [Na+] in/[Na]out created by depolarization in a nerve cell if the final potential is +50 mV at 37 C? A) 6.4  106 B) 6.5 C) 1.5 D) 0.15 E) 1.6  10-7

Answer: B Difficulty: Hard Section Reference: 9-1 Learning Objective: Analyze the thermodynamics of solute movement across membranes 3) Inside a nerve cell at rest, [Na+] is _____ and [K+] _____ relative to the concentrations seen outside the cell.

A) high; high B) high; low C) low; high

D) low; low E) low; equal Answer: C Difficulty: Medium Section Reference: 9-1 Learning Objective: Analyze the thermodynamics of solute movement across membranes

4) Nerve cells contain high levels of _____ which is a derivative of _____.

A) phosphatidylethanolamine; palmitic acid B) cholesterol; isoprene C) phosphatidylcholine, phosphatidic acid D) sphingomyelin; sphingosine E) ganglioside GM1; ceramide Answer: D Difficulty: Medium Section Reference: 9-1 Learning Objective: Analyze the thermodynamics of solute movement across membranes 5) After depolarization of a nerve cell, what event restores the resting potential?

A) K+ efflux B) K+ influx C) Na+ efflux D) Na+ influx E) Cl- efflux Answer: A Difficulty: Medium Section Reference: 9-1 Learning Objective: Analyze the thermodynamics of solute movement across membranes 6) For a cell with [Na+] out= 150 mM and [Na+]in = 15 mM at 37 C, what is the free energy for movement of sodium ions from outside the cell to inside if the potential across the membrane is 60 mV? A) 11.7 kJ/mol B) 0.145 kJ/mol

C) -0.145 kJ/mol D) -11.7 kJ/mol E) cannot be calculated from given information Answer: D Difficulty: Hard Section Reference: 9-1 Learning Objective: Analyze the thermodynamics of solute movement across membranes

7) The movement of glucose into a cell when blood sugar is high is accomplished by _____. The movement of K+ against its concentration gradient is accomplished by _____.

A) simple diffusion; active transport B) passive transport; passive transport C) active transport; membrane potential D) simple diffusion; passive transport E) passive transport; active transport Answer: E Difficulty: Medium Section Reference: 9-1 Learning Objective: Analyze the thermodynamics of solute movement across membranes 8) All known porins are _____ proteins composed of _____.

A) monomeric; seven transmembrane -helices B) dimeric; -barrels C) dimeric; three transmembrane -helices D) trimeric; -barrels E) trimeric; four transmembrane -helices Answer: D Difficulty: Medium Section Reference: 9-2 Learning Objective: Describe the operation of passive transport systems such as ion channels and transport proteins 9) Which of the following will cause the opening or closing of a gated ion channel?

A) pH change

B) phosphorylation C) voltage change D) ligand binding E) all of the above Answer: E Difficulty: Easy Section Reference: 9-2 Learning Objective: Describe the operation of passive transport systems such as ion channels and transport proteins 10) What type of transporter is responsible for moving water across membranes?

A) aquachannel B) aquaporin C) aquaphore D) aquaporter E) aquapermease Answer: B Difficulty: Easy Section Reference: 9-2 Learning Objective: Describe the operation of passive transport systems such as ion channels and

transport proteins 11) Which of the following statements regarding membrane transporters is true?

A) a porin is always open but only transports solutes in one direction B) an ion channel selective for K+ will also allow Na+ through since both are small enough to fit through the channel C) amphotericin is able to assemble inside a membrane in such a manner to form a channel through which K+ and Na+ flow, thus disrupting the ion gradient D) K+ channels can work in both directions, allowing the neuronal action potential to move in multiple directions E) none of the above Answer: C Difficulty: Medium Section Reference: 9-2 Learning Objective: Describe the operation of passive transport systems such as ion channels and

transport proteins

12) Which amino acid in the aquaporin channel hydrogen bonds with water to prevent the movement of protons?

A) Asn B) Leu C) Phe D) Val E) Ile Answer: A Difficulty: Easy Section Reference: 9-2 Learning Objective: Describe the operation of passive transport systems such as ion channels and transport proteins 13) What is a transporter that moves two different molecules or ions in the same direction?

A) uniporter B) diporter C) symporter D) antiporter E) none of the above Answer: C Difficulty: Easy Section Reference: 9-2 Learning Objective: Describe the operation of passive transport systems such as ion channels and transport proteins 14) Which of the following is true regarding the glucose transporter?

A) in addition to glucose, it will transport any other monosaccharide with six carbons B) binding of glucose causes a conformational change so that the transporter is never open on both sides of the membrane C) ATP hydrolysis prevents the transporter from working in reverse D) it is able to transport glucose into a cell against a concentration gradient E) none of the above Answer: B

Difficulty: Medium Section Reference: 9-2 Learning Objective: Describe the operation of passive transport systems such as ion channels and transport proteins 15) The Na,K-ATPase is a(n) _____ that moves Na+ from _____ and K+ from _____.

A) antiporter; inside to out; outside to in B) antiporter; outside to in; inside to out C) symporter; inside to out; inside to out D) symporter; outside to in; outside to in E) none of the above Answer: A Difficulty: Medium Section Reference: 9-3 Learning Objective: Describe the operation of active transport systems

16) Hydrolysis of ATP by the Na,K-ATPase moves _____ while hydrolysis of the phosphate moves _____. A) 3 Na+; 2 K+ B) 2 Na+; 3 K+ C) 3 K+; 2 Na+ D) 2 K+; 3 Na+ E) none of the above Answer: A Difficulty: Medium Section Reference: 9-3 Learning Objective: Describe the operation of active transport systems

17) The P-glycoprotein is an example of a(n) _____ which has been linked to drug resistance in the treatment of _____.

A) ABC transporter; bacterial infections B) ABC transporter; cancer C) Na,K-ATPase; viral infections D) Na,K-ATPase; parasitic infections E) none of the above

Answer: B Difficulty: Medium Section Reference: 9-3 Learning Objective: Describe the operation of active transport systems

18) Transport of glucose from the intestine into the intestinal cells is accomplished by a(n) ________. This is an example of ___________.

A) uniporter; passive transport B) uniporter; primary active transport C) symporter; primary active transport D) symporter; secondary active transport E) antiporter; secondary active transport Answer: D Difficulty: Hard Section Reference: 9-3 Learning Objective: Describe the operation of active transport systems

19) A sudden increase in the concentration of _____ causes the release of acetylcholine from the axon of a nerve cell.

A) Na+ B) K+ C) Ca2+ D) ClE) H+ Answer: C Difficulty: Easy Section Reference: 9-4 Learning Objective: Outline the mechanics of membrane fusion

20) Which of the following would be the first to occur following opening of Ca2+ channels during acetylcholine-mediated neurotransmission to a muscle cell?

A) binding of SNARE complex to synaptic vesicles and pre-synaptic membrane B) binding of acetylcholine to muscle cell receptors C) reuptake of acetylcholine by the nerve cell D) hydrolysis of acetylcholine by acetylcholinesterase

E) release of acetylcholine by the nerve cell Answer: A Difficulty: Medium Section Reference: 9-4 Learning Objective: Outline the mechanics of membrane fusion

21) Which type of ion channel is blocked by lidocaine, a local anesthetic?

A) K+ B) Na+ C) pre-synaptic Ca2+ D) post-synaptic Ca2+ E) none of the above Answer: B Difficulty: Medium Section Reference: 9-4 Learning Objective: Outline the mechanics of membrane fusion

22) Serotonin reuptake occurs by a(n) _____.

A) uniporter B) antiporter using Na+ C) antiporter using Ca2+ D) symporter using Na+ E) symporter using Ca2+ Answer: D Difficulty: Medium Section Reference: 9-4 Learning Objective: Outline the mechanics of membrane fusion

23) Which of the following is true regarding SNARE complex formation?

A) prior to membrane association, SNARE proteins are in an unfolded state B) two proteins of the SNARE complex come from the membrane and one from the synaptic vesicle C) formation of a four-helix complex is critical for membrane association of the vesicle D) formation of the SNARE complex is thermodynamically favorable, as is membrane fusion

E) all of the above Answer: E Difficulty: Hard Section Reference: 9-4 Learning Objective: Outline the mechanics of membrane fusion

24) Which of the following occurs during the fusion of a synaptic vesicle and cell membrane?

A) SNARE complexes dissociate to allow membrane fusion to occur B) addition of triacylglycerols to the membrane allows the bilayer to bow inward C) selective removal of acyl chains from membrane phospholipids allows the bilayer to bow outward D) the composition of the two membranes has no effect upon the rate of fusion E) none of the above Answer: C Difficulty: Hard Section Reference: 9-4 Learning Objective: Outline the mechanics of membrane fusion

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 10 Question type: Multiple Choice 1) Hormones bind to _____ with _____ affinity.

A) ligands; low B) agonists; high C) antagonists; low D) G proteins; low E) receptors; high Answer: E Difficulty: Medium Section Reference: 10-1 Learning Objective: Summarize the properties of a receptor

2) When a receptor loses its ability to transmit a signal following continuous exposure to a ligand, the receptor is said to be _____.

A) saturated B) desensitized C) transduced D) specific E) none of the above Answer: B Difficulty: Easy Section Reference: 10-1 Learning Objective: Summarize the properties of a receptor

3) Which of the following can be a hormone?

A) amino acid derivatives B) steroids C) polypeptides D) eicosanoids E) all of the above

Answer: E Difficulty: Medium Section Reference: 10-1 Learning Objective: Summarize the properties of a receptor 4) A sample of cells with a total receptor concentration of 50 M was incubated with a ligand concentration of 100 M. Following the incubation period, the concentration of unbound receptors was determined to be 15 M. What is the Kd for the receptor-ligand interaction?

A) 28 M B) 43 M C) 143 M D) 217 M E) 333 M Answer: A Difficulty: Hard Section Reference: 10-1 Learning Objective: Summarize the properties of a receptor 5) A small molecule produced inside a cell in response to a hormone binding to its receptor is called a(n) _____.

A) inside messenger B) agonist C) antagonist D) second messenger E) G protein Answer: D Difficulty: Easy Section Reference: 10-1 Learning Objective: Summarize the properties of a receptor 6) Which of the following is a ligand of the 2-adrenergic receptor?

A) tyrosine B) serotonin C) norepinephrine

D) caffeine E) adenosine Answer: C Difficulty: Easy Section Reference: 10-2 Learning Objective: Describe the GPCR signaling pathways from receptors to second messengers

7) Activation of a G protein in response to hormone binding requires binding of _____ to the _____ subunit.

A) GDP;  B) GTP;  C) GDP;  D) GTP;  E) GDP;  Answer: B Difficulty: Medium Section Reference: 10-2 Learning Objective: Describe the GPCR signaling pathways from receptors to second messengers 8) What enzyme is activated by association with an active G protein?

A) adenylate cyclase B) cAMP phosphodiesterase C) protein kinase A D) protein kinase G E) all of the above Answer: A Difficulty: Easy Section Reference: 10-2 Learning Objective: Describe the GPCR signaling pathways from receptors to second messengers 9) The second messenger _____ is produced by the enzyme _____.

A) nitric oxide; arginase B) cGMP; GTP cyclase C) cAMP; adenylate cyclase

D) triacylglycerol; phospholipase C E) inositol diphosphate; phospholipase C Answer: C Difficulty: Medium Section Reference: 10-2 Learning Objective: Describe the GPCR signaling pathways from receptors to second messengers

10) cAMP binds to the _____ subunits of protein kinase A allowing the tetramer to dissociate into _____.

A) active subunits; an active dimer and two inactive monomers B) active subunits; two active monomers and an inactive dimer C) regulatory subunits; an active dimer and two inactive monomers D) regulatory subunits; two active monomers and an inactive dimer E) regulatory subunits; two active monomers and two inactive monomers Answer: D Difficulty: Hard Section Reference: 10-2 Learning Objective: Describe the GPCR signaling pathways from receptors to second messengers 11) What two amino acid residues are the targets of protein kinase A? A) Asn and Gln B) Thr and Ser C) Tyr and Thr D) Ser and Tyr E) Cys and Ser Answer: B Difficulty: Easy Section Reference: 10-2 Learning Objective: Describe the GPCR signaling pathways from receptors to second messengers 12) Desensitization of a G protein-coupled receptor is caused by phosphorylation of the receptor by a specific kinase. What protein recognizes the phosphorylated receptor?

A) phospholipase C B) the G protein  subunit

C) cAMP phosphodiesterase D) adenosine receptor E) arrestin Answer: E Difficulty: Medium Section Reference: 10-2 Learning Objective: Describe the GPCR signaling pathways from receptors to second messengers

13) The second messenger _____ opens Ca2+ channels in the endoplasmic reticulum.

A) inositol trisphosphate B) diacylglycerol C) cAMP D) cGMP E) nitric oxide Answer: A Difficulty: Easy Section Reference: 10-2 Learning Objective: Describe the GPCR signaling pathways from receptors to second messengers 14) Ligand binding to a receptor tyrosine kinase causes _____ of the receptor which then _____ the next protein in the signaling pathway.

A) methylation; hydrolyzes B) hydrolysis; inhibits C) phosphorylation; phosphorylates D) acylation; activates E) none of the above Answer: C Difficulty: Medium Section Reference: 10-1 and 10-3 Learning Objective: Describe how tyrosine kinase pathways are activated 15) The _____ receptor is a receptor tyrosine kinase.

A) 1- adrenergic B) 2-adrenergic

C) calmodulin D) insulin E) cortisol Answer: D Difficulty: Easy Section Reference: 10-3 Learning Objective: Describe how tyrosine kinase pathways are activated

16) Activity of the Ras protein is analogous to the _____ in terms of its ability to bind GTP. A) G protein  subunit B) G protein  subunit C) G protein  subunit D) calmodulin E) all of the above Answer: A Difficulty: Medium Section Reference: 10-3 Learning Objective: Describe how tyrosine kinase pathways are activated 17) Where are the ultimate targets of the Ras-dependent signaling cascade located within the cell?

A) cytoplasm B) nucleus C) endoplasmic reticulum D) mitochondria E) cell membrane Answer: B Difficulty: Medium Section Reference: 10-3 Learning Objective: Describe how tyrosine kinase pathways are activated 18) The ability for some receptor tyrosine kinases to ultimately activate phospholipase C is an example of _____.

A) antagonism

B) desensitization C) autophosphorylation D) poor receptor-ligand specificity E) cross-talk Answer: E Difficulty: Medium Section Reference: 10-2 and 10-3 Learning Objective: Describe how tyrosine kinase pathways are activated

19) Which of the following hormones is able to cross biological membranes and thus the receptor is found inside the cell, not on the cell surface?

A) insulin B) glucagon C) cortisol D) epinephrine E) platelet derived growth factor Answer: C Difficulty: Easy Section Reference: 10-4 Learning Objective: List some types of lipid hormones and their physiological effects

20) The complex formed between a lipid hormone and its receptor binds to _____ which are specific DNA sequences.

A) transcription factors B) nuclear localization sequences C) DNA-binding domains D) hormone response elements E) none of the above Answer: D Difficulty: Easy Section Reference: 10-4 Learning Objective: List some types of lipid hormones and their physiological effects

21) The eicosanoids are derived from the membrane fatty acid _____.

A) stearic acid B) linoleic acid C) -linolenic acid D) arachidonic acid E) docosahexaenoic acid (DHA) Answer: D Difficulty: Easy Section Reference: 10-4 Learning Objective: List some types of lipid hormones and their physiological effects

22) Which of the following is an inhibitor of cyclooxygenase?

A) acetaminophen B) aspirin C) eicosanoic acid D) thromboxane E) progesterone Answer: B Difficulty: Medium Section Reference: 10-4 Learning Objective: List some types of lipid hormones and their physiological effects 23) Which of the following can be regulated by eicosanoids?

A) blood pressure B) blood coagulation C) inflammation D) fever E) all of the above Answer: E Difficulty: Easy Section Reference: 10-4 Learning Objective: List some types of lipid hormones and their physiological effects

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 11 Question type: Multiple Choice 1) The molecular formula for a monosaccharide is _____ where _____. A) CnH2n+2On; n3 B) CnH2nOn; n  3 C) CnH2nOn; n  4 D) CnH2n+2On; n  4 E) none of the above Answer: B Difficulty: Easy Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives 2) The three-carbon monosaccharide _____ is a(n) _____.

A) dihydroxyacetone; enantiomer B) fructose; triose C) ribose; hemiacetal D) galactose; ketose E) glyceraldehyde; aldose Answer: E Difficulty: Medium Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives 3) What is the only monosaccharide that is achiral?

A) glyceraldehyde B) ribose C) galactose D) dihydroxyacetone E) fructose

Answer: D Difficulty: Medium Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives

4) Glucose and galactose are _____ of each other.

A) epimers B) enantiomers C) diastereomers D) anomers E) none of the above Answer: A Difficulty: Easy Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives

5) Which of the following best describes the relationship between the following molecules?

A) epimers B) anomers C) diastereomers D) pentoses E) one is a D sugar, one is an L sugar Answer: E Difficulty: Medium Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives 6) Which of the monosaccharides seen below are L sugars?

A) A and B B) A and C C) B and C D) C and D E) A, B and C Answer: D Difficulty: Medium Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives 7) Which monosaccharide(s) seen below is(are) the enantiomer(s) of A?

A) B B) C C) D D) B and C E) C and D Answer: C Difficulty: Medium Section Reference: 11-1

Learning Objective: Identify the structural features of monosaccharides and their derivatives 8) Which two monosaccharides seen below are epimers?

A) A and B B) A and C C) B and C D) C and D E) B and D Answer: A Difficulty: Easy Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives 9) The transformation of a monosaccharide into its _____ occurs easily and does not require the assistance of a catalyst.

A) epimer B) anomer C) sugar alcohol D) diastereomer E) none of the above Answer: B Difficulty: Medium Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives 10) In the following structure, which carbon is the anomeric carbon?

A) A B) B C) C D) D E) E Answer: E Difficulty: Medium Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives 11) Which of the following Haworth projections correctly shows the  anomer of galactose?

A) A B) B C) C D) D E) none of the above Answer: D Difficulty: Hard Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives 12) At equilibrium in solution, D-glucose consists of a mixture of its anomers. Which statement most accurately describes the solution?

A) consists of approximately equal amounts of the - and -anomers B) the -anomer is more stable and is slightly preferred over the -anomer C) the -anomer predominates over the -anomer by a ratio of approximately 2:1 D) straight-chain form is present in high concentration E) none of the above Answer: C Difficulty: Easy Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives

13) The reaction between an alcohol and an anomeric carbon of a carbohydrate forms a _____ bond.

A) anomeric B) glycosidic C) hemiacetal D) ester E) ether Answer: B Difficulty: Easy Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives 14) Any sugar that has a free aldehyde group is called a(n) _____.

A) reducing sugar B) non-reducing sugar C) ketose D) aldohexose E) alditol Answer: A Difficulty: Easy Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives 15) Which of the following is glucose-6-phosphate?

A) A B) B C) C D) D E) none of the above Answer: C Difficulty: Medium Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives 16) Which of the following would be positively charged at physiological pH? A) glucuronic acid B) fructose-6-phosphate C) xylitol D) glucosamine E) all of the above Answer: D Difficulty: Easy Section Reference: 11-1 Learning Objective: Identify the structural features of monosaccharides and their derivatives 17) The following is a(n) _____ disaccharide with a(n) _____ glycosidic bond.

A) ; (1→ 4) B) ; (1→ 1)

C) ; (1→4) D) ; (1→1) E) ; (1→4) Answer: C Difficulty: Hard Section Reference: 11-2 Learning Objective: Relate the structures of polysaccharides to their biological functions

18) Which of the following disaccharides has both anomeric carbons involved in the glycosidic bond?

A) lactose B) maltose C) amylose D) chitin E) sucrose Answer: E Difficulty: Easy Section Reference: 11-2 Learning Objective: Relate the structures of polysaccharides to their biological functions 19) Lactase, the enzyme responsible for breaking lactose into its monomers, is a(n) _____ enzyme.

A) -galactosidase B) -amylase C) -glycosidase D) -glycosyltransferase E) none of the above Answer: A Difficulty: Medium Section Reference: 11-2 Learning Objective: Relate the structures of polysaccharides to their biological functions

20) Amylopectin contains primarily _____ glycosidic bonds with _____ glycosidic bonds as branch points.

A) (1→4); (1→2) B) (1→4); (1→6) C) (1→4); (1→6) D) (1→4); (1→4) E) (1→4); (1→6) Answer: B Difficulty: Medium Section Reference: 11-2 Learning Objective: Relate the structures of polysaccharides to their biological functions

21) Which of the following is the major difference between glycogen and amylopectin?

A) glycogen contains -glycosidic bonds, amylopectin contains -glycosidic bonds B) glycogen is branched, amylopectin is linear C) glycogen contains a reducing end, amylopectin does not D) glycogen contains about twice the number of branch points as amylopectin E) glycogen is found in plants, amylopectin is found in animals Answer: D Difficulty: Medium Section Reference: 11-2 Learning Objective: Relate the structures of polysaccharides to their biological functions 22) Which of the following are characteristic of cellulose?

A) highly extended fibers B) (1→4) glycosidic bonds C) extensive hydrogen bonding between individual molecules D) unbranched polymer E) all of the above Answer: E Difficulty: Easy Section Reference: 11-2 Learning Objective: Relate the structures of polysaccharides to their biological functions 23) Which of the following is a heteropolysaccharide?

A) amylopectin

B) cellulose C) pectin D) chitin E) none of the above Answer: C Difficulty: Easy Section Reference: 11-2 Learning Objective: Relate the structures of polysaccharides to their biological functions

24) The enzyme _____ from _____ allows animals such as cows to derive energy from cellulose.

A) chitinase; termites B) cellulase; microorganisms C) glucosyltransferase; viruses D) lactase; microorganisms E) none of the above Answer: B Difficulty: Medium Section Reference: 11-2 Learning Objective: Relate the structures of polysaccharides to their biological functions 25) Which of the following is a major difference between cellulose and chitin?

A) chitin is produced by insects, cellulose is produced by plants B) chitin contains glucose and glucosamine, cellulose contains only glucose C) chitin contains (1→6) glycosidic bonds, cellulose contains (1→4) glycosidic bonds D) chitin is a branched polymer, cellulose is linear E) none of the above Answer: A Difficulty: Medium Section Reference: 11-2 Learning Objective: Relate the structures of polysaccharides to their biological functions

26) Unlike proteins and oligonucleotides, polysaccharides _____.

A) are readily metabolized in the absence of specialized enzymes B) often have branched structures C) are achiral D) are always completely water soluble E) are components of every known living organism Answer: B Difficulty: Medium Section Reference: 11-2 Learning Objective: Relate the structures of polysaccharides to their biological functions

27) O-linked oligosaccharides are commonly attached to the oxygen of _____.

A) ribose B) tyrosine C) lysine D) threonine E) galactose Answer: D Difficulty: Easy Section Reference: 11-3 Learning Objective: Summarize the structures and functions of glycoproteins 28) N-linked oligosaccharides can be covalently linked to proteins at the amino acid _____.

A) Gln B) Pro C) Lys D) Arg E) Asn Answer: E Difficulty: Easy Section Reference: 11-3 Learning Objective: Summarize the structures and functions of glycoproteins 29) The initial addition of oligosaccharides of N-glycosylated proteins occurs in the _____.

A) lysosome B) Golgi apparatus C) endoplasmic reticulum D) vacuole E) cytoplasm Answer: C Difficulty: Easy Section Reference: 11-3 Learning Objective: Summarize the structures and functions of glycoproteins

30) Processing of N-glycosylated proteins within the Golgi apparatus involves the removal of monosaccharides by _____ and addition of new monosaccharides by _____.

A) glycosidases; glycosyltransferases B) epimerases; glycosidases C) cellulases; lactases D) glycosyltransferases; N-amidases E) proteases; glycosylases Answer: A Difficulty: Medium Section Reference: 11-3 Learning Objective: Summarize the structures and functions of glycoproteins

31) What glycosidic bonds are seen in the following portion of an N-linked oligosaccharide?

Abbreviations: galactose: Gal; glucose: Glu; N-acetylglucosamine: NAG

A) (1→ 4) between Gal and NAG; (1→6) between Glu and NAG B) (1→ 4) between Gal and NAG; (1→3) between Glu and NAG

C) (1→3) between Gal and NAG; (1→4) between Glu and NAG D) (1→4) between Gal and NAG; (1→3) between Glu and NAG E) (1→4) between Gal and NAG; (1→3) between Glu and NAG Answer: D Difficulty: Hard Section Reference: 11-3 Learning Objective: Summarize the structures and functions of glycoproteins

32) In the ABO blood type system, how many monosaccharides are found in each of the oligosaccharides for the various blood types?

A) A: 3, B) A: 4, C) A: 6, D) A: 6, E) A: 5,

B: 4, B: 5, B: 5, B: 6, B: 5,

O: 3 O: 4 O: 5 O: 5 O: 4

Answer: E Difficulty: Hard Section Reference: 11-3 Learning Objective: Summarize the structures and functions of glycoproteins 33) In a _____, the carbohydrate is responsible for most of the mass; in a _____, the protein is responsible for most of the mass.

A) glycoprotein; proteoglycan B) proteoglycan; glycoprotein C) N-linked glycoprotein; O-linked glycoprotein D) O-linked glycoprotein; N-linked glycoprotein E) N-linked proteoglycan; O-linked glycoprotein proteoglycan Answer: B Difficulty: Medium Section Reference: 11-3 Learning Objective: Summarize the structures and functions of glycoproteins 34) Chondroitin sulfate, shown below, contains which of the following?

A) a (1→3) glycosidic bond B) a (1→4) glycosidic bond C) a glucuronic acid residue D) a sulfate ester of N-acetylgalactosamine E) all of the above Answer: E Difficulty: Hard Section Reference: 11-3 Learning Objective: Summarize the structures and functions of glycoproteins 35) Which of the following describes glycosaminoglycans?

A) found in extracellular space B) associated with the cytoskeleton C) bound to other proteins to minimize interactions with water D) homopolymer composed of only one type of monosaccharide E) none of the above Answer: A Difficulty: Easy Section Reference: 11-3 Learning Objective: Summarize the structures and functions of glycoproteins 36) Bacterial cell walls are made of _____.

A) pectin B) chondroitin sulfate C) peptidoglycans

D) keratin sulfate E) heparin Answer: C Difficulty: Easy Section Reference: 11-3 Learning Objective: Summarize the structures and functions of glycoproteins

37) The active portion of the penicillin molecule is the _____ ring.

A) glucopyranose B) fructofuranose C) 5-membered sulfur containing D) -lactam E) none of the above Answer: D Difficulty: Medium Section Reference: 11-3 Learning Objective: Summarize the structures and functions of glycoproteins

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 12 Question type: Multiple Choice 1) Plants are considered _____.

A) chemoautotrophs B) photoautotrophs C) chemoheterotrophs D) photoheterotrophs E) none of the above Answer: B Difficulty: Easy Section Reference: 12-1 Learning Objective: Summarize the pathways for digesting and mobilizing metabolic fuels

2) Energy is generated during _____, the breakdown of larger molecules into smaller while energy is consumed during _____, the building of larger molecules from smaller ones.

A) reduction reactions; oxidation reactions B) autotrophic reactions; heterotrophic reactions C) catabolic reactions; anabolic reactions D) hydrolysis reactions; condensation reactions E) none of the above Answer: C Difficulty: Easy Section Reference: 12-1 Learning Objective: Summarize the pathways for digesting and mobilizing metabolic fuels

3) Digestion of food by mammals converts _____ into _____ which can be absorbed from the intestines.

A) proteins; dipeptides and tripeptides B) polysaccharides; monosaccharides and disaccharides C) cholesterol; acetyl CoA D) nucleic acids; polynucleotides

E) triacylglycerols; fatty acids Answer: E Difficulty: Medium Section Reference: 12-1 Learning Objective: Summarize the pathways for digesting and mobilizing metabolic fuels

4) Digestion of food utilizes enzymes that catalyze _____ reactions.

A) hydrolysis B) reduction C) condensation D) oxidative E) group transfer Answer: A Difficulty: Easy Section Reference: 12-1 Learning Objective: Summarize the pathways for digesting and mobilizing metabolic fuels

5) Which of the following is used to move lipids around the bloodstream? A) micelles B) liposomes C) liposuctions D) lipoproteins E) cholesterol esters Answer: D Difficulty: Easy Section Reference: 12-1 Learning Objective: Summarize the pathways for digesting and mobilizing metabolic fuels

6) The bulk of triacylglycerols in the human body are stored in _____.

A) liver cells B) adipocytes C) muscle cells D) nerve cells E) lipoproteins

Answer: B Difficulty: Easy Section Reference: 12-1 Learning Objective: Summarize the pathways for digesting and mobilizing metabolic fuels

7) The _____ stores glucose as glycogen and converts excess glucose to _____.

A) muscle; amino acids B) adipose tissue; fatty acids C) liver; fatty acids D) brain; energy E) none of the above Answer: C Difficulty: Medium Section Reference: 12-1 Learning Objective: Summarize the pathways for digesting and mobilizing metabolic fuels

8) Amino acids can be converted to _____.

A) carbohydrates B) fatty acids C) nucleotides D) peptides E) all of the above Answer: E Difficulty: Easy Section Reference: 12-1 Learning Objective: Summarize the pathways for digesting and mobilizing metabolic fuels

9) Which of the following is mobilized for energy use by a phosphorolysis reaction, not a hydrolysis?

A) glycogen B) protein C) triacylglycerols D) polynucleotides E) cholesterol esters

Answer: A Difficulty: Easy Section Reference: 12-1 Learning Objective: Summarize the pathways for digesting and mobilizing metabolic fuels

10) Degradation of proteins within a cell can occur within the _____ or by use of _____.

A) endoplasmic reticulum; protease enzymes chymotrypsin and trypsin B) Golgi apparatus; protease enzymes chymotrypsin and trypsin C) endoplasmic reticulum; a proteasome D) lysosome; a proteasome E) mitochondria; ubiquitin Answer: D Difficulty: Medium Section Reference: 12-1 Learning Objective: Summarize the pathways for digesting and mobilizing metabolic fuels

11) The _____-terminus of ubiquitin is linked to a _____ residue of proteins to be degraded. A) N; Asp B) N; Glu C) C; Lys D) C; Ser E) C; Tyr Answer: C Difficulty: Easy Section Reference: 12-1 Learning Objective: Summarize the pathways for digesting and mobilizing metabolic fuels

12) Which of the following molecules is involved with the oxidation of glucose, synthesis of fatty acids and oxidation of fatty acids?

A) pyruvate B) acetyl-CoA C) alanine D) oxaloacetate E) glyceraldehyde-3-phosphate

Answer: B Difficulty: Medium Section Reference: 12-2 Learning Objective: Recognize the common chemical features of metabolic pathways 13) A reaction that results in the loss of electrons from a molecule is a(n) _____.

A) reduction B) ligation C) hydrolysis D) oxidation E) phosphorolysis Answer: D Difficulty: Easy Section Reference: 12-2 Learning Objective: Recognize the common chemical features of metabolic pathways 14) Which of the following is more highly oxidized than acetaldehyde?

A) ethane B) ethanol C) ethylene D) ethylene glycol E) acetic acid Answer: E Difficulty: Medium Section Reference: 12-2 Learning Objective: Recognize the common chemical features of metabolic pathways 15) The oxidized form of NADH is _____.

A) NADH+ B) NAD+ C) NADH D) NADH2 E) none of the above

Answer: B Difficulty: Easy Section Reference: 12-2 Learning Objective: Recognize the common chemical features of metabolic pathways 16) Which of the following molecules is in the most reduced state?

A) methane B) formaldehyde C) formic acid D) methanol E) carbon dioxide Answer: A Difficulty: Medium Section Reference: 12-2 Learning Objective: Recognize the common chemical features of metabolic pathways 17) The conversion of a carbohydrate into CO2 is a(n) _____ process; the conversion of CO2 into a carbohydrate is a(n) _____ process.

A) reductive; oxidative B) endergonic; exergonic C) exergonic; endergonic D) oxidative; exergonic E) endergonic; reductive Answer: C Difficulty: Medium Section Reference: 12-2 Learning Objective: Recognize the common chemical features of metabolic pathways 18) Which of the following is a lipid-soluble electron carrier in its reduced state?

A) NADPH B) NADH C) NAD+ D) ubiquinol E) ubiquinone

Answer: D Difficulty: Easy Section Reference: 12-2 Learning Objective: Recognize the common chemical features of metabolic pathways

19) Which of the following is correct regarding metabolic pathways?

A) most pathways are isolated from other pathways B) the activity of most pathways is not regulated C) all cells within a multi-cellular organism contain the same pathways D) anabolic pathways never occur at the same time as catabolic pathways E) none of the above are correct Answer: E Difficulty: Hard Section Reference: 12-2 Learning Objective: Recognize the common chemical features of metabolic pathways

20) Which of the following is correctly described?

A) proteome: the complete set of proteins present in a cell at a given time B) metabolome: the complete set of metabolic enzymes active in a cell at a given time C) transcriptome: the complete set of proteins being synthesized at a given time D) genome: the complete set of genes that are expressed at a given time E) none of the above Answer: A Difficulty: Hard Section Reference: 12-2 Learning Objective: Recognize the common chemical features of metabolic pathways

21) Which of the following is an essential amino acid? A) Ala B) Val C) Cys D) Tyr E) Gly Answer: B

Difficulty: Easy Section Reference: 12-2 Learning Objective: Recognize the common chemical features of metabolic pathways 22) Which of the following vitamins is correctly paired with its biochemical function?

A) folic acid: carboxylation reactions B) biotin: decarboxylation reactions C) riboflavin: acyl transfer reactions D) pyridoxine: amino-group transfer reactions E) pantothenic acid: redox reactions Answer: D Difficulty: Medium Section Reference: 12-2 Learning Objective: Recognize the common chemical features of metabolic pathways 23) Which of the following vitamins is correctly paired with the disease that is caused by its deficiency?

A) biotin: scurvy B) pantothenic acid: beriberi C) nicotinamide: pellagra D) thiamine: anemia E) folic acid: rickets Answer: C Difficulty: Medium Section Reference: 12-2 Learning Objective: Recognize the common chemical features of metabolic pathways 24) When a reaction is at equilibrium, the G is equal to _____.

A) 1 B) 0 C) -1 D) ΔG° E) none of the above Answer: B

Difficulty: Easy Section Reference: 12-3 Learning Objective: Analyze the free energy changes that occur during metabolic reactions

25) If the ΔG° is known, how can Keq be calculated?

A) K eq = log (ΔG°/RT) e B) K eq = e(ΔG°/TS) C) Keq = RT ln ΔG° D) K eq = -(ΔG°/RT) e E) Keq = ln (ΔG°/TS) Answer: D Difficulty: Hard Section Reference: 12-3 Learning Objective: Analyze the free energy changes that occur during metabolic reactions 26) For the following reaction, calculate the Keq at 25°C. succinyl-CoA + acetoacetate

acetoacetyl-CoA + succinate ΔG° = -1.25 kJ/mol

A) 0.602 B) 1.00 C) 1.66 D) 3.21 E) 4.22  102 Answer: C Difficulty: Hard Section Reference: 12-3 Learning Objective: Analyze the free energy changes that occur during metabolic reactions 27) For the following reaction, calculate the ΔG° at 37°C. glucose-6-phosphate A) -2.87 kJ/mol B) -1.70 kJ/mol C) 0.203 kJ/mol

fructose-6-phosphate

Keq = 0.517

D) -0.738 kJ/mol E) 1.70 kJ/mol Answer: E Difficulty: Medium Section Reference: 12-3 Learning Objective: Analyze the free energy changes that occur during metabolic reactions

28) For the following reaction, calculate the ΔG at 37°C, given concentrations for glucose-1phosphate of 25 mM and glucose-6-phosphate of 1 mM. glucose-1-phosphate

glucose-6-phosphate

ΔG° = -7.1 kJ/mol

A) -15.4 kJ/mol B) -8.1 kJ/mol C) -6.1 kJ/mol D) 1.2 kJ/mol E) none of the above Answer: A Difficulty: Hard Section Reference: 12-3 Learning Objective: Analyze the free energy changes that occur during metabolic reactions 29) What is the intracellular glucose concentration if the ΔG for the following reaction is20.1 kJ/mol at 37°C and concentrations for glucose-6-phosphate and phosphate are both 1 mM? glucose-6-phosphate

glucose + Pi

ΔG° = -13.8 kJ/mol

A) 1.9 M B) 87 M C) 1.9 mM D) 27 mM E) 87 mM Answer: E Difficulty: Hard Section Reference: 12-3 Learning Objective: Analyze the free energy changes that occur during metabolic reactions

30) Which of the following describes the bonding of the three phosphates to adenosine in ATP? How many phosphoanhydride bonds are found in ATP? A) one phosphoanhydride bond, two low energy phosphate esters B) two phosphoanhydride bonds, one low energy phosphate ester C) three phosphoanhydride bonds, one low energy phosphate ester D) three phosphoanhydride bonds E) none of the above Answer: B Difficulty: Medium Section Reference: 12-3 Learning Objective: Analyze the free energy changes that occur during metabolic reactions 31) If the following reactions were coupled, what would be the overall ΔG°? glucose + Pi ATP + H2O

glucose-6-phosphate ADP + Pi

ΔG° = 13.8 kJ/mol ΔG° = -30.5 kJ/mol

A) 44.3 kJ/mol B) 16.7 kJ/mol C) 0 kJ/mol D) -16.7 kJ/mol E) -44.3 kJ/mol Answer: D Difficulty: Medium Section Reference: 12-3 Learning Objective: Analyze the free energy changes that occur during metabolic reactions 32) Generally speaking, ATP is produced by _____ reactions and used by _____ reactions.

A) catabolic; anabolic B) anabolic; catabolic C) endergonic; exergonic D) oxidation; reduction E) reduction; oxidation Answer: A Difficulty: Easy Section Reference: 12-3

Learning Objective: Analyze the free energy changes that occur during metabolic reactions 33) Which of the following factors contributes to the highly exergonic nature of ATP hydrolysis?

A) removal of phosphate from the cytoplasm B) addition of water to the hydrophilic ATP molecule C) decrease in negative-ion repulsion in ATP D) low energy of activation for the hydrolysis E) none of the above Answer: C Difficulty: Medium Section Reference: 12-3 Learning Objective: Analyze the free energy changes that occur during metabolic reactions

34) Which of the following has the most spontaneous hydrolysis?

A) 1,3-bisphosphoglycerate B) phosphocreatine C) glucose-1-phosphate D) pyrophosphate E) phosphoenolpyruvate Answer: E Difficulty: Easy Section Reference: 12-3 Learning Objective: Analyze the free energy changes that occur during metabolic reactions

35) In highly active muscle, _____ is used to regenerate ATP. A) phosphocreatine B) 1,3-bisphosphoglycerate C) pyrophosphate D) phosphoenolpyruvate E) acetyl-CoA Answer: A Difficulty: Easy Section Reference: 12-3 Learning Objective: Analyze the free energy changes that occur during metabolic reactions

36) The ΔG° for the hydrolysis of acetyl CoA is most similar to the ΔG° for the hydrolysis of _____.

A) 1,3-bisphosphoglycerate B) ATP C) glucose-1-phosphate D) glucose-6-phosphate E) phosphoenolpyruvate Answer: B Difficulty: Easy Section Reference: 12-3 Learning Objective: Analyze the free energy changes that occur during metabolic reactions

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 13 Question type: Multiple Choice 1) The process of _____ converts glucose into _____.

A) electron transport; CO2 B) glycolysis; pyruvate C) glycogenolysis; glycogen D) gluconeogenesis; glycogen E) glycogen synthesis; pyruvate Answer: B Difficulty: Easy Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 2) What pathway is used to make glucose from other metabolites such as oxaloacetate?

A) glycogen synthesis B) glycogen degradation C) glycolysis D) pentose phosphate pathway E) gluconeogenesis Answer: E Difficulty: Easy Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 3) In eukaryotes, glycolysis typically occurs in the _____, gluconeogenesis typically occurs in the _____.

A) mitochondria; cytosol B) Golgi apparatus; mitochondria C) endoplasmic reticulum; mitochondria

D) cytosol; cytosol E) lysosome; cytosol Answer: D Difficulty: Easy Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

4) The coenzyme _____ is the oxidizing agent in glycolysis.

A) ADP B) thiamine pyrophosphate C) NAD+ D) FAD E) biotin Answer: C Difficulty: Easy Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 5) Which of the following represents the net products of glycolysis from one molecule of glucose?

A) 2 pyruvate, 2 NADH, 2 ATP B) 2 pyruvate, 2 NADH, 4 ATP C) 3 pyruvate, 2 NADH, 4 ATP D) 6 CO2, 30 ATP E) 6 CO2, 32 ATP Answer: A Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 6) In glycolysis, the net gain of ATP during the energy investment phase is _____ while the net gain of ATP during the energy payoff phase is _____.

A) -4; 6 B) -2; 4 C) -2; 2 D) -1; 3 E) 0; 2 Answer: B Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

7) Hexokinase is an example of a(n) _____ enzyme A) ligase B) hydrolase C) transferase D) ligase E) isomerase Answer: C Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 8) With a G of -16.7 kJ/mol, the reaction catalyzed by hexokinase is considered to be _____.

A) at equilibrium B) substrate and product concentration dependent C) freely reversible D) metabolically irreversible E) none of the above Answer: D Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

9) Phosphoglucose isomerase has a G of 2.2 kJ/mol but a G of -1.4 kJ/mol. Based upon this difference, which of the following is true?

A) within a cell, concentrations are non-standard B) within a cell, the concentration of glucose-6-phosphate is higher than fructose-6-phosphate C) within a cell, concentrations of products are often lowered by their rapid use in other reactions D) within a cell, the reaction catalyzed by phosphoglucose isomerase would be considered freely reversible E) all of the above Answer: E Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

10) Which of the following enzymes requires ATP as a substrate?

A) phosphofructokinase B) phosphoglucose isomerase C) aldolase D) triose phosphate isomerase E) enolase Answer: A Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 11) What enzyme catalyzes the major regulatory step of glycolysis?

A) hexokinase B) aldolase C) glyceraldehyde-3-phosphate dehydrogenase D) phosphofructokinase E) phosphoglucose isomerase Answer: D Difficulty: Easy

Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 12) Which of the following is a potent activator of phosphofructokinase in mammals?

A) fructose-6-phosphate B) glucose-6-phosphate C) fructose-2,6-bisphosphate D) fructose-1,6-bisphosphate E) glyceraldehyde-3-phosphate Answer: C Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

13) In bacterial cells, _____ is an activator of phosphofructokinase while _____ is an inhibitor.

A) glucose-6-phosphate; ATP B) ADP; phosphoenolpyruvate C) fructose-2,6-bisphosphate; fructose-6-phosphate D) AMP; glyceraldehyde-3-phosphate E) citrate; ADP Answer: B Difficulty: Hard Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

14) The enzyme responsible for the synthesis of fructose-2,6-bisphosphate is _____.

A) phosphofructokinase-2 B) hexosephosphatekinase-2 C) aldolase-2 D) phosphofructose isomerase-2 E) none of the above Answer: A

Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 15) Which enzyme is responsible for splitting a hexose into two trioses? A) enolase B) phosphoglycerate mutase C) phosphofructose isomerase D) triose phosphate isomerase E) aldolase Answer: E Difficulty: Easy Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

16) The active site of aldolase contains a Lys residue which forms a(n) _____ and a(n) _____ residue that participates in acid-base reactions.

A) amide; His B) Schiff base; Asp C) secondary amine; Glu D) amide; Cys E) Schiff base; Tyr Answer: E Difficulty: Hard Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

17) In the reaction catalyzed by aldolase, the bond broken is between carbons 3 and 4 of the substrate. What functional groups are present on these two carbons (C3 and C4) in the products?

A) C3 becomes an alcohol; C4 becomes a carboxylic acid B) C3 becomes an aldehyde; C4 becomes a ketone C) C3 becomes an aldehyde; C4 becomes an alcohol

D) C3 becomes an alcohol; C4 becomes an aldehyde E) C3 becomes a ketone; C4 becomes an alcohol Answer: D Difficulty: Hard Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

18) Triose phosphate isomerase catalyzes a reaction that is most similar to _____.

A) phosphoglycerate mutase B) phosphoglucose isomerase C) hexokinase D) aldolase E) enolase Answer: B Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

19) What is the name for the process that produces ATP from ADP in glycolysis?

A) substrate-level phosphorylation B) oxidative phosphorylation C) autophosphorylation D) glycolytic phosphorylation E) cytosolic phosphorylation Answer: A Difficulty: Easy Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

20) Experimental evidence indicates that glyceraldehyde-3-phosphate dehydrogenase contains a critical _____ residue in its active site, as shown by its inactivation by iodoacetamide.

A) Lys B) His C) Asp D) Ser E) Cys Answer: E Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

21) Glyceraldehyde-3-phosphate dehydrogenase oxidizes _____.

A) an alcohol to a ketone B) a carboxylic acid to CO2 C) an alcohol to an aldehyde D) an aldehyde to a carboxylic acid E) an aldehyde to an alcohol Answer: D Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 22) Glyceraldehyde is oxidized to _____ which can transfer a phosphate to _____.

A) phosphoenolpyruvate; ADP B) phosphoenolpyruvate; AMP C) 1,3-bisphosphoglycerate; ADP D) 1,3-bisphosphoglycerate; AMP E) 3-phosphoglycerate; ADP Answer: C Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

23) Why is phosphoglycerate kinase still considered a kinase even though ADP is converted to ATP? A) the enzyme is freely reversible B) ATP is the ultimate source of the phosphate that is transferred to ADP C) the phosphate is transferred in conjunction with an oxidation reaction D) the reaction is metabolically irreversible E) none of the above Answer: A Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

24) What residue of phosphoglycerate mutase undergoes covalent catalysis during the reaction?

A) Asp B) His C) Ser D) Tyr E) Cys Answer: B Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

25) What type of enzyme is enolase, which catalyzes the conversion of 2-phosphoglycerate to phosphoenolpyruvate and water?

A) transferase B) hydrolase C) ligase D) lyase E) oxidoreductase Answer: D Difficulty: Medium Section Reference: 13-1

Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 26) What is the greatest driving force for the reaction catalyzed by pyruvate kinase?

A) hydrolysis of phosphate from phosphoenolpyruvate B) transfer of phosphate from phosphoenolpyruvate to ADP C) release of ATP from active site D) tautomerization of enolpyruvate to pyruvate E) release of pyruvate from the active site Answer: D Difficulty: Hard Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

27) What sort of activity does fructose-1,6-bisphosphate have on pyruvate kinase?

A) no effect B) competitive inhibitor C) noncompetitive inhibitor D) allosteric inhibitor E) feed-forward activator Answer: E Difficulty: Easy Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

28) Which of the following contains a high energy bond that is used for a substrate-level phosphorylation in glycolysis?

A) fructose-1,6-bisphosphate B) 1,3-bisphosphoglycerate C) acetyl phosphate D) 2,3-bisphosphoglycerate E) 1-phosphoglycerate Answer: B

Difficulty: Easy Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 29) What regulatory enzyme of glycolysis is skipped during fructose metabolism?

A) hexokinase B) phosphoglucose isomerase C) phosphofructokinase D) pyruvate kinase E) fructose metabolism does not skip any steps of glycolysis Answer: C Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 30) If a cell were given glucose labeled at carbon-3 with 14C, what carbon(s) of pyruvate would contain the label?

A) 1 B) 2 C) 3 D) 1 and 3 E) 2 and 3 Answer: A Difficulty: Hard Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

31) Under anaerobic conditions in skeletal muscle, pyruvate is converted into _____.

A) ethanol and CO2 B) propionate C) acetyl-CoA D) lactate

E) alanine Answer: D Difficulty: Easy Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

32) Fill in the missing reagents in the following reaction.

A) reactant: NAD+ + H+; product: NADH B) reactant: NADH + H+; product: NAD+ C) reactant: ATP; product: ADP + Pi D) reactant: NADH + H+; product: CO2 E) none of the above Answer: B Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 33) Under aerobic conditions, pyruvate is converted to _____ by pyruvate dehydrogenase.

A) oxaloacetate B) ethanol C) lactate D) glucose E) acetyl-CoA Answer: E Difficulty: Medium Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis 34) What coenzyme is required for the conversion of pyruvate to oxaloacetate?

A) NADH B) pyridoxal phosphate C) biotin D) thiamine E) FADH2 Answer: C Difficulty: Easy Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

35) Which of the following correctly describes the mechanism of pyruvate carboxylase?

A) ATP and bicarbonate react, carboxyphosphate formed, carboxyl group transferred to biotin, deprotonated pyruvate attacks carboxyl group B) ATP and bicarbonate react, carboxyl group transferred to biotin carboxyphosphate formed, deprotonated pyruvate attacks carboxyl group C) ATP and bicarbonate react, carboxyphosphate formed, deprotonated pyruvate attacks carboxyl group, carboxyl group transferred to biotin D) carboxyphosphate formed, ATP and bicarbonate react, carboxyl group transferred to biotin, deprotonated pyruvate attacks carboxyl group E) carboxyphosphate formed, deprotonated pyruvate attacks carboxyl group, ATP and bicarbonate react, carboxyl group transferred to biotin Answer: A Difficulty: Hard Section Reference: 13-1 Learning Objective: Describe the substrate, product, and chemical reaction for each step of glycolysis

36) Which of the following forms a substrate cycle with hexokinase?

A) phosphoglucose isomerase B) glucose-6-phosphatase C) phosphofructokinase D) phosphoglycerate kinase E) fructose bisphosphatase Answer: B

Difficulty: Medium Section Reference: 13-2 Learning Objective: Describe the substrates, products, enzymes, and regulation of gluconeogenesis 37) Which of the following can serve as a source of carbon for gluconeogenesis?

A) glycerol B) serine C) alanine D) glutamate E) all of the above Answer: E Difficulty: Medium Section Reference: 13-2 Learning Objective: Describe the substrates, products, enzymes, and regulation of gluconeogenesis

38) How many equivalents of ATP are required to convert two molecules of pyruvate to glucose? A) 2 B) 4 C) 6 D) 8 E) 10 Answer: C Difficulty: Medium Section Reference: 13-2 Learning Objective: Describe the substrates, products, enzymes, and regulation of gluconeogenesis

39) What would occur if both phosphofructokinase and fructose bisphosphatase were active simultaneously?

A) a futile cycle B) a substrate cycle C) an inhibitor cycle D) the alanine cycle E) the Cori cycle Answer: A

Difficulty: Easy Section Reference: 13-2 Learning Objective: Describe the substrates, products, enzymes, and regulation of gluconeogenesis 40) Gluconeogenesis is most active in the _____.

A) muscles B) brain C) heart D) liver E) kidneys Answer: D Difficulty: Easy Section Reference: 13-2 Learning Objective: Describe the substrates, products, enzymes, and regulation of gluconeogenesis

41) Fructose-2,6-bisphosphate is an activator of _____ and an inhibitor of _____. A) phosphofructokinase; hexokinase B) fructose bisphosphatase; phosphofructokinase C) phosphofructokinase; fructose bisphosphatase D) glucose-6-phosphatase; pyruvate kinase E) pyruvate kinase; phosphoenolpyruvate carboxykinase Answer: C Difficulty: Medium Section Reference: 13-2 Learning Objective: Describe the substrates, products, enzymes, and regulation of gluconeogenesis

42) Muscle cells are not able to supply glucose for other tissues because they do not contain which of the following enzymes?

A) debranching enzyme B) pyruvate carboxylase C) glycogen phosphorylase D) fructose bisphosphatase E) glucose-6-phosphatase Answer: E

Difficulty: Hard Section Reference: 13-2 Learning Objective: Describe the substrates, products, enzymes, and regulation of gluconeogenesis 43) Which of the following supplies the energy for glycogen synthesis?

A) ATP B) GTP C) CTP D) UTP E) none of the above Answer: C Difficulty: Easy Section Reference: 13-3 Learning Objective: Compare the processes of glycogen synthesis and degradation 44) Which of the following correctly relates the order of intermediates during the synthesis of glycogen?

A) glucose → glucose-1-phosphate → glucose-6-phosphate → UDP-glucose → glycogen B) glucose → glucose-6-phosphate → glucose-1-phosphate → UDP-glucose → glycogen C) glucose → glucose-6-phosphate → UDP-glucose → glucose-1-phosphate → glycogen D) glucose → UDP-glucose → glucose-1-phosphate → glucose-6-phosphate → glycogen E) glucose → UDP-glucose → glucose-6-phosphate → glucose-1-phosphate → glycogen Answer: B Difficulty: Medium Section Reference: 13-3 Learning Objective: Compare the processes of glycogen synthesis and degradation 45) Which of the following enzymes catalyzes the conversion of glucose-1-phosphate to glucose6-phosphate?

A) phosphoglucomutase B) glucose phosphatase C) glycogen phosphorylase D) phosphoglucose isomerase E) phosphorylase mutase

Answer: A Difficulty: Easy Section Reference: 13-3 Learning Objective: Compare the processes of glycogen synthesis and degradation

46) In glycogen synthesis, what is the intermediate between glucose-1-phosphate and glycogen?

A) glucose-6-phosphate B) glucose-1,6-bisphosphate C) UTP-glucose D) UDP-glucose E) none of the above Answer: D Difficulty: Easy Section Reference: 13-3 Learning Objective: Compare the processes of glycogen synthesis and degradation

47) In the muscle, when a residue of glucose is cleaved from glycogen and converted to pyruvate via glycolysis, what is the net ATP production? A) 1 B) 2 C) 3 D) 4 E) 5 Answer: C Difficulty: Medium Section Reference: 13-3 Learning Objective: Compare the processes of glycogen synthesis and degradation

48) Glycogen storage occurs in _____ and _____ tissue.

A) muscle; kidney B) liver; pancreas C) brain; muscle D) kidney; pancreas E) muscle; liver

Answer: E Difficulty: Easy Section Reference: 13-3 Learning Objective: Compare the processes of glycogen synthesis and degradation 49) The main enzyme of glycogen catabolism is _____, which catalyzes a _____ reaction.

A) glycogen hydrolase; hydrolysis B) glycogen phosphorylase; phosphorolysis C) glycogen mutase; mutarotation D) debranching enzyme; hydrolysis E) glycogen transferase; glucose residue transfer Answer: B Difficulty: Medium Section Reference: 13-3 Learning Objective: Compare the processes of glycogen synthesis and degradation 50) NADPH used in lipid biosynthesis is produced in _____.

A) the pentose phosphate pathway B) the citric acid cycle C) glycolysis D) gluconeogenesis E) none of the above Answer: A Difficulty: Easy Section Reference: 13-4 Learning Objective: Describe the enzymes, substrates, and products of the pentose phosphate pathway 51) For each molecule of glucose-6-phosphate that enters the pentose phosphate pathway, _____ NADPH and _____ CO2 are produced.

A) 1; 0 B) 1; 1 C) 2; 1 D) 2; 2 E) 3; 2

Answer: C Difficulty: Medium Section Reference: 13-4 Learning Objective: Describe the enzymes, substrates, and products of the pentose phosphate pathway

52) Which of the following enzymes catalyzes an oxidative decarboxylation reaction?

A) glucose-6-phosphate dehydrogenase B) glyceraldehyde-3-phosphate dehydrogenase C) glycogen dehydrogenase D) 6-phosphogluconate dehydrogenase E) none of the above Answer: D Difficulty: Medium Section Reference: 13-4 Learning Objective: Describe the enzymes, substrates, and products of the pentose phosphate pathway

53) Which of the following requires large amounts of both ribose-5-phosphate and NADPH? A) DNA synthesis B) amino acid synthesis C) lipid synthesis D) glycogen synthesis E) cholesterol synthesis Answer: A Difficulty: Easy Section Reference: 13-4 Learning Objective: Describe the enzymes, substrates, and products of the pentose phosphate pathway

54) In the event that NADPH is needed but ribose is not, which of the following is an end product of the pentose phosphate pathway?

A) ribulose-5-phosphate B) dihydroxyacetone phosphate

C) fructose-1,6-bisphosphate D) 1,3-bisphosphoglycerate E) glyceraldehyde-3-phosphate Answer: E Difficulty: Medium Section Reference: 13-4 Learning Objective: Describe the enzymes, substrates, and products of the pentose phosphate pathway

55) In the conversion of ribulose-5-phosphate to glycolytic intermediates, which of the following enzymes is used?

A) phosphoglucomutase B) transketolase C) phosphoglycerate mutase D) phosphofructoisomerase E) none of the above Answer: B Difficulty: Medium Section Reference: 13-4 Learning Objective: Describe the enzymes, substrates, and products of the pentose phosphate pathway

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 14 Question type: Multiple Choice 1) What cellular location contains pyruvate dehydrogenase and most of the citric acid cycle enzymes?

A) cytosol B) mitochondrial matrix C) inner mitochondrial membrane D) mitochondrial inter-membrane space E) outer mitochondrial membrane Answer: B Difficulty: Easy Section Reference: 14-1 Learning Objective: Summarize the reactions carried out by the pyruvate dehydrogenase complex 2) Which of the following is correct concerning the reaction catalyzed by pyruvate dehydrogenase?

A) it is an oxidative decarboxylation B) it is activated by high concentrations of ATP C) the enzyme contains a pyridoxal phosphate prosthetic group D) the reaction is an anaplerotic reaction since it can replace citric acid intermediates that are removed for other pathways E) the enzyme contains two different types of subunits Answer: A Difficulty: Medium Section Reference: 14-1 Learning Objective: Summarize the reactions carried out by the pyruvate dehydrogenase complex

3) Which of the following indicates the correct order of product release by pyruvate dehydrogenase?

A) acetyl-CoA, CO2, NADH B) NADH, CO2, acetyl-CoA C) CO2, NADH, acetyl-CoA D) CO2, acetyl-CoA, NADH E) NADH, acetyl-CoA, CO2 Answer: D Difficulty: Medium Section Reference: 14-1 Learning Objective: Summarize the reactions carried out by the pyruvate dehydrogenase complex

4) Which of the following pyruvate dehydrogenase enzymes is correctly paired with the coenzyme that is associated with it?

A) E1: coenzyme A B) E2: thiamine pyrophosphate C) E3: FAD D) E2: NAD+ E) E3: lipoamide Answer: C Difficulty: Medium Section Reference: 14-1 Learning Objective: Summarize the reactions carried out by the pyruvate dehydrogenase complex 5) Which of the following coenzymes is directly responsible for the oxidation of the hydroxyethyl group to the acetyl group?

A) coenzyme A B) thiamine pyrophosphate C) FAD D) NAD+ E) lipoamide Answer: E Difficulty: Easy Section Reference: 14-1 Learning Objective: Summarize the reactions carried out by the pyruvate dehydrogenase complex

6) What amino acid is covalently linked to lipoic acid in E2? A) Lys B) Ser C) His D) Gln E) Thr Answer: A Difficulty: Easy Section Reference: 14-1 Learning Objective: Summarize the reactions carried out by the pyruvate dehydrogenase complex

7) What type of bond forms when the hydroxyethyl group is transferred to lipoamide?

A) ester B) amide C) thioester D) anhydride E) none of the above Answer: C Difficulty: Easy Section Reference: 14-1 Learning Objective: Summarize the reactions carried out by the pyruvate dehydrogenase complex 8) Which of the following is an inhibitor of pyruvate dehydrogenase?

A) CoA B) pyruvate C) FADH2 D) NADH E) CO2 Answer: D Difficulty: Easy Section Reference: 14-1

Learning Objective: Summarize the reactions carried out by the pyruvate dehydrogenase complex 9) In the citric acid cycle, what reduced cofactors are derived from the oxidation of one molecule of acetyl CoA to two molecules of CO2?

A) 2 NADH and 1 QH2 B) 3 NADH and 1 QH2 C) 2 NADH and 2 QH2 D) 3 NADH and 2 QH2 E) 4 NADH and 2 QH2 Answer: B Difficulty: Easy Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle 10) What makes the reaction catalyzed by citrate synthase highly exergonic?

A) hydrolysis of ATP B) hydrolysis of GTP C) decarboxylation reaction D) conversion from keto to enol tautomer E) hydrolysis of thioester Answer: E Difficulty: Medium Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

11) Which of the following explains the proper binding of the two substrates for citrate synthase?

A) the binding is random B) acetyl-CoA binds, then oxaloacetate C) oxaloacetate binds, then acetyl-CoA D) oxaloacetate binds to one subunit, acetyl-CoA binds to the other E) in one subunit, acetyl-CoA binds, then oxaloacetate; on the other subunit, this is reversed

Answer: C Difficulty: Hard Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

12) Which of the following is observed in the mechanism of citrate synthase?

A) a histidine residue acts as a base, deprotonating oxaloacetate B) an aspartic acid residue acts as a base, deprotonating oxaloacetate C) a histidine residue hydrogen bonds with the carbonyl oxygen of oxaloacetate to enable a nucleophilic attack D) removal of the CoA is accomplished by transfer to a serine residue, then hydrolysis E) all of the above Answer: B Difficulty: Hard Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

13) Which of the following condenses with oxaloacetate to form citrate?

A) acetyl-CoA B) cis-aconitate C) carboxybiotin D) oxalosuccinate E) succinyl-phosphate Answer: A Difficulty: Easy Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

14) Which of the following is an intermediate between citrate and isocitrate in the citric acid cycle?

A) oxalosuccinate B) succinyl-phosphate

C) cis-aconitate D) carboxybiotin E) hydroxyethyl-TPP Answer: C Difficulty: Easy Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

15) Aconitase catalyzes the _____ of citrate to aconitate followed by the _____ of aconitate to isocitrate. A) oxidation; reduction B) reduction; oxidation C) hydration; dehydration D) dehydration; hydration E) isomerization; isomerization Answer: D Difficulty: Hard Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

16) Which of the following describes the isomerization of citrate to isocitrate?

A) a major regulatory step for the citric acid cycle B) an oxidation reaction C) the only unnecessary step of the citric acid cycle D) protects cells from the toxic effects of arsenite ion E) converts a tertiary alcohol, which cannot easily be oxidized, to a secondary alcohol that can be oxidized Answer: E Difficulty: Medium Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

17) Given the following structure of isocitrate, the carbon labeled _____ is lost as CO2 by isocitrate dehydrogenase while the carbon labeled _____ is lost as CO2 by -ketoglutarate dehydrogenase.

A) 1; 2 B) 2; 1 C) 1; 3 D) 3; 1 E) 2; 3 Answer: E Difficulty: Hard Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle 18) During the oxidation of isocitrate, the intermediate that is decarboxylated to form αketoglutarate is _____.

A) oxalosuccinate B) succinyl-phosphate C) cis-aconitate D) carboxybiotin E) hydroxyethyl-TPP Answer: A Difficulty: Medium Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle 19) Which enzyme catalyzes a reaction most similar to that catalyzed by -ketoglutarate dehydrogenase?

A) glyceraldehyde-3-phosphate dehydrogenase

B) pyruvate dehydrogenase C) isocitrate dehydrogenase D) succinate dehydrogenase E) malate dehydrogenase Answer: B Difficulty: Medium Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

20) Which of the following enzymes catalyzes a substrate-level phosphorylation?

A) malate synthase B) succinate dehydrogenase C) -ketoglutarate dehydrogenase D) succinyl-CoA synthetase E) fumarase Answer: D Difficulty: Easy Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle 21) Which of the following amino acids participates in the transfer of a phosphate group in the reaction catalyzed by succinyl-CoA synthetase?

A) lysine B) serine C) glutamine D) aspartic acid E) histidine Answer: E Difficulty: Medium Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

22) Which of the following is an enzyme-associated intermediate that is similar in energy to 1,3bisphosphoglycerate?

A) phosphohistidine B) succinyl phosphate C) oxalosuccinate D) carboxybiotin E) hydroxyethyl-TPP Answer: B Difficulty: Hard Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

23) Which of the following enzymes contains an FAD prosthetic group?

A) pyruvate dehydrogenase B) isocitrate dehydrogenase C) succinate dehydrogenase D) -ketoglutarate dehydrogenase E) malate dehydrogenase Answer: C Difficulty: Easy Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle 24) Where is succinate dehydrogenase located?

A) mitochondrial matrix B) mitochondrial inner membrane C) mitochondrial inter-membrane space D) mitochondrial outer membrane E) none of the above Answer: B Difficulty: Easy Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each

step of the citric acid cycle 25) The oxidation of succinate to fumarate is best characterized as an oxidation of _____.

A) an alkane to an alkene B) an alcohol to an aldehyde C) an alcohol to a ketone D) an aldehyde to a carboxylic acid E) a -keto acid to CO2 and a carboxylic acid that is one carbon smaller Answer: A Difficulty: Medium Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle 26) The reaction catalyzed by fumarase is _____.

A) an isomerization of an alcohol B) a dehydration of an alcohol C) a hydroxylation of an alkene D) a hydration of an alkene E) none of the above Answer: D Difficulty: Medium Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

27) How does the reaction catalyzed by malate dehydrogenase proceed despite a G of 29.7 kJ/mol?

A) an elevated [H+] allows the reaction to proceed B) high levels of NAD+ allow the reaction to proceed C) concentrations of oxaloacetate are kept very low by rapid use in the subsequent step D) the enzyme is unique in its ability only to catalyze the reaction in one direction E) the enzyme catalyzed reaction under cellular conditions has a much smaller energy of activation Answer: C

Difficulty: Hard Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle 28) How many electrons are transferred from one acetyl group when it is converted to two carbon dioxide molecules in the citric acid cycle? A) 2 B) 4 C) 6 D) 8 E) 10 Answer: D Difficulty: Easy Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

29) If acetyl-CoA labeled on the methyl carbon were used as the substrate for the citric acid cycle, where would the labeled carbon appear in oxaloacetate produced from one round of the cycle? A) C1 B) C4 C) C1 or C2 D) C1 or C4 E) C2 or C3 Answer: E Difficulty: Hard Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

30) If all reduced electron carriers are reoxidized to run oxidative phosphorylation, how many ATP can be generated from the oxidation of one acetyl-CoA? A) 6

B) 10 C) 15 D) 20 E) 32 Answer: B Difficulty: Easy Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle

31) Which of the following is an equilibrium-controlled step within the mitochondria?

A) malate dehydrogenase B) isocitrate dehydrogenase C) citrate synthase D) pyruvate dehydrogenase E) -ketoglutarate dehydrogenase Answer: A Difficulty: Medium Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle 32) Which of the following is activated by ADP? A) malate dehydrogenase B) aconitase C) isocitrate dehydrogenase D) citrate synthase E) succinyl-CoA synthetase Answer: C Difficulty: Easy Section Reference: 14-2 Learning Objective: Describe the substrate, product, chemical reaction, and regulation for each step of the citric acid cycle 33) Which of the following can be converted into glutamic acid in a single enzyme-catalyzed

step?

A) isocitrate B) oxaloacetate C) malate D) -ketoglutarate E) succinyl-CoA Answer: D Difficulty: Easy Section Reference: 14-3 Learning Objective: List the pathways that consume and generate citric acid cycle intermediates 34) Which of the following can be converted into glucose using parts of the citric acid cycle?

A) malate B) isocitrate C) glutamic acid D) succinate E) all of the above Answer: E Difficulty: Medium Section Reference: 14-3 Learning Objective: List the pathways that consume and generate citric acid cycle intermediates 35) What citric acid cycle intermediate is effectively used as a mechanism for the transport of acetyl-CoA from the mitochondria to the cytosol?

A) citrate B) isocitrate C) fumarate D) malate E) oxaloacetate Answer: A Difficulty: Easy Section Reference: 14-3 Learning Objective: List the pathways that consume and generate citric acid cycle intermediates

36) When acetyl-CoA and NADPH are needed for lipid synthesis, which of the following reactions is used to produce NADPH in the cytosol?

A) reduction of oxaloacetate to malate B) oxidation of malate to pyruvate C) reduction of fumarate to succinate D) oxidation of malate to oxaloacetate E) oxidation of isocitrate to -ketoglutarate Answer: B Difficulty: Medium Section Reference: 14-3 Learning Objective: List the pathways that consume and generate citric acid cycle intermediates 37) Which of the following is an anaplerotic reaction that is often used in the cell?

A) conversion of pyruvate to acetyl-CoA B) conversion of -ketoglutarate to glutamic acid C) conversion of citrate to oxaloacetate and acetyl-CoA D) conversion of pyruvate to oxaloacetate E) conversion of succinyl-CoA to heme Answer: D Difficulty: Medium Section Reference: 14-3 Learning Objective: List the pathways that consume and generate citric acid cycle intermediates 38) Which of the following terms indicates that the citric acid cycle is both catabolic and anabolic in nature?

A) cataplerotic B) amphipathic C) anaplerotic D) diabolic E) amphibolic Answer: E Difficulty: Easy Section Reference: 14-3 Learning Objective: List the pathways that consume and generate citric acid cycle intermediates

39) Which of the following is activated by high levels of acetyl-CoA? A) malate dehydrogenase B) succinyl-CoA synthetase C) pyruvate carboxylase D) pyruvate dehydrogenase E) -ketoglutarate dehydrogenase Answer: C Difficulty: Medium Section Reference: 14-3 Learning Objective: List the pathways that consume and generate citric acid cycle intermediates 40) Which of the following enzymes allows for a net increase of citric acid cycle metabolites without expending any energy in the form of ATP or its equivalents?

A) alanine aminotransferase B) pyruvate dehydrogenase C) pyruvate carboxylase D) citrate lyase E) none of the above Answer: A Difficulty: Hard Section Reference: 14-3 Learning Objective: List the pathways that consume and generate citric acid cycle intermediates 41) Which of the following can cause a large increase in the activity of the citric acid cycle?

A) activation of isocitrate dehydrogenase by ADP B) activation of -ketoglutarate dehydrogenase by Ca2+ C) increasing concentrations of oxaloacetate by pyruvate carboxylase D) increasing concentrations of -ketoglutarate by transamination E) all of the above Answer: E Difficulty: Medium Section Reference: 14-3 Learning Objective: List the pathways that consume and generate citric acid cycle intermediates

42) The mechanism of malate synthase that catalyzes the conversion of glyoxylate and acetyl- CoA to malate would be most similar to which citric acid cycle enzyme? A) fumarase B) aconitase C) citrate synthase D) isocitrate dehydrogenase E) succinyl-CoA synthetase Answer: C Difficulty: Medium Section Reference: 14-3 Learning Objective: List the pathways that consume and generate citric acid cycle intermediates

43) Why can germinating plant seeds convert acetyl-CoA from fatty acids into carbohydrates, while animals are incapable of converting fatty acids into glucose?

A) animals have glycogen and don't need to make glucose from fatty acids B) plants, not animals, use the glyoxylate cycle to convert acetyl CoA to oxaloacetate C) plant seeds use photosynthesis to make sugar D) animals use the citric acid cycle exclusively for energy production, plants only use glycolysis for energy E) none of the above Answer: B Difficulty: Medium Section Reference: 14-3 Learning Objective: List the pathways that consume and generate citric acid cycle intermediates

44) What citric acid cycle enzyme is not used in the glyoxylate cycle?

A) isocitrate dehydrogenase B) fumarase C) malate dehydrogenase D) aconitase E) succinate dehyrogenase Answer: A Difficulty: Medium Section Reference: 14-3

Learning Objective: List the pathways that consume and generate citric acid cycle intermediates

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 15 Question type: Multiple Choice 1) The oxidation of FADH2 to FAD involves the transfer of _____; the oxidation of NADH to NAD+ involves the transfer of _____.

A) a hydrogen atom and an H+; a hydride B) two hydrogen atoms; a hydride C) a hydride and an H+; a hydrogen atom and an H+ D) a hydride; two hydrogen atoms E) two hydrides; one hydride Answer: B Difficulty: Hard Section Reference: 15-1 Learning Objective: Summarize the thermodynamics of oxidation–reduction reactions 2) Which of the following is the correct half reaction for the oxidation of acetaldehyde? + 2 A) acetaldehyde acetate + 3H + 2e+ HO→ B) acetate- + 3H+ + 2e- → acetaldehyde + H2O C) acetaldehyde + 2 H+ + 2e- → ethanol D) ethanol → acetaldehyde + 2 H+ + 2e2 + H++ 2e-→ pyruvateE) acetaldehyde + CO

Answer: A Difficulty: Medium Section Reference: 15-1 Learning Objective: Summarize the thermodynamics of oxidation–reduction reactions 3) If the following half-reactions are combined, what is the potential for the spontaneous reaction? oxaloacetate- + 2H+ + 2e- → malate-

 = -0.166

NAD+ + H+ + 2e- → NADH

 = -0.315

A) -0.481 V

B) -0.149 V C) 0.0523 V D) 0.149 V E) .0481 V Answer: D Difficulty: Medium Section Reference: 15-1 Learning Objective: Summarize the thermodynamics of oxidation–reduction reactions

4) If the reduction potential for NAD+ is -0.315 V and the reduction potential for oxygen is 0.815 V, what is the potential for the oxidation of NADH by oxygen?

A) -1.13 V B) -0.50 V C) 0.185 V D) 0.50 V E) 1.13 V Answer: E Difficulty: Medium Section Reference: 15-1 Learning Objective: Summarize the thermodynamics of oxidation–reduction reactions 5) In a muscle cell at 37C, if the concentrations of pyruvate and lactate are 100 M and 50M respectively, what is the actual reduction potential if  for pyruvate reduction is -0.185 V? A) -0.194 V B) -0.186 V C) -0.176 V D) 0.176 V E) 0.194 V Answer: C Difficulty: Hard Section Reference: 15-1 Learning Objective: Summarize the thermodynamics of oxidation–reduction reactions

6) What is the G for the reduction of pyruvate to lactate by NADH given the following half reactions?

pyruvate- + 2H+ + 2e- → lactateNAD+ + H+ + 2e- → NADH

 = -0.185  = -0.315

A) -96.5 kJ/mol B) -25.1 kJ/mol C) -12.5 kJ/mol D) 25.1 kJ/mol E) 96.5 kJ/mol Answer: B Difficulty: Hard Section Reference: 15-1 Learning Objective: Summarize the thermodynamics of oxidation–reduction reactions 7) What does the reduction potential of 0.815 V for the reduction of water to oxygen indicate?

A) water is a very strong reducing agent B) water is a very strong reducing agent and oxygen is a very strong oxidizing agent C) oxygen is a very strong oxidizing agent D) water will be spontaneously reduced to oxygen E) none of the above Answer: C Difficulty: Easy Section Reference: 15-1 Learning Objective: Summarize the thermodynamics of oxidation–reduction reactions 8) For eukaryotes, where are the Complexes of electron transport located?

A) cytosol B) outer mitochondrial membrane C) mitochondrial intermembrane space D) inner mitochondrial membrane E) mitochondrial matrix Answer: D Difficulty: Easy Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway

9) What genes are found in the mitochondrial genome?

A) electron transport proteins B) citric acid cycle enzymes C) fatty acid oxidation enzymes D) outer membrane transport proteins E) none of the above Answer: A Difficulty: Medium Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway 10) What is the terminal electron acceptor in aerobic organisms?

A) NAD+ B) FAD C) ubiquinone D) varies from one organism to another E) none of the above Answer: E Difficulty: Easy Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway 11) In the malate-aspartate shuttle, _____ is reduced to _____ in the cytosol.

A) aspartate; oxaloacetate B) oxaloacetate; malate C) aspartate; malate D) malate; aspartate E) malate; oxaloacetate Answer: B Difficulty: Medium Section Reference: 15-2

Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway 12) In the malate aspartate shuttle, _____ is transferred into the mitochondria while _____ is transferred to the cytosol.

A) NADH; NAD+ B) NAD+; NADH C) malate; oxaloacetate D) malate; aspartate E) oxaloacetate; aspartate Answer: D Difficulty: Easy Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway 13) Which of the following transport mechanisms is used in the inner mitochondrial membrane?

IMS = intermembrane space A) antiport of ATP from IMS to matrix, ADP from matrix to IMS B) symport of ATP and H+ from matrix to IMS C) symport of Pi and H+from IMS to matrix D) antiport of ADP from IMS to matrix, Pi from matrix to IMS E) symport of ADP and H+ from IMS to matrix Answer: C Difficulty: Hard Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway 14) The reduction potentials of all prosthetic groups of Complex I have reduction potentials between _____ and _____.

A) NAD+; ubiquinone B) NADH; ubiquinol C) FAD; ubiquinone D) ubiquinone; oxygen E) ubiquinone; cytochrome c

Answer: A Difficulty: Medium Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway 15) The process of _____ allows electrons to be transferred between redox centers that are up to 1.4 nm apart.

A) reduction B) swinging arm electron transfer C) electron shuttling D) electron teleporting E) tunneling Answer: E Difficulty: Easy Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway 16) Which of the following represents the correct order of electron flow in Complex I? A) NADH → ubiquinone → Fe-S clusters → FMN B) NADH → Fe-S clusters → FMN → ubiquinone C) NADH → FMN → ubiquinone → Fe-S clusters D) NADH → FMN → Fe-S clusters → ubiquinone E) NADH → ubiquinone → FMN → Fe-S clusters Answer: D Difficulty: Hard Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway 17) How many protons are transported from the matrix to the intermembrane space by Complex I? A) 0

B) 2 C) 4 D) 6 E) 8 Answer: C Difficulty: Easy Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway

18) What shuttle mechanism transfers cytosolic NADH into the mitochondria with a loss of reductive power, with the electrons entering the electron transport chain as ubiquinol instead of NADH? A) glycerol-3-phosphate shuttle B) alanine aminotransferase shuttle C) malate-aspartate shuttle D) adenine nucleotide shuttle E) none of the above Answer: A Difficulty: Medium Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway

19) Which of the following is a source of ubiquinol?

A) Complex I B) fatty acyl-CoA dehydrogenase C) succinate dehydrogenase D) mitochondrial dehydrogenase E) all of the above Answer: E Difficulty: Medium Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway

20) Complex III accepts electrons from _____ and transfers them to _____.

A) cytochrome c; cytochrome a B) ubiquinol; cytochrome c C) ubiquinone; cytochrome c D) ubiquinol; cytochrome b E) ubiquinone; cytochrome a Answer: B Difficulty: Easy Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway

21) The cytochromes undergo which of the following oxidation reactions?

A) Fe3+ → Fe2+ B) Fe0 → Fe2+ C) Fe2+ → Fe3+ D) Cu1+ → Cu2+ E) Cu2+ → Cu1+ Answer: C Difficulty: Easy Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway 22) How many protons are moved across the inner mitochondrial membrane at Complex III? A) 1 B) 2 C) 3 D) 4 E) none of the above Answer: D Difficulty: Easy Section Reference: 15-2

Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway 23) Which of the following results from the first round of the Q cycle?

A) two reduced cytochrome c and one ubiquinone B) one reduced cytochrome c and one ubiquinone C) one reduced cytochrome c, one reduced cytochrome B and one ubiquinone D) two reduced cytochrome c and one ubiquinol E) one reduced cytochrome c and one semiquinone Answer: E Difficulty: Medium Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway

24) Ubiquinone is a _____ molecule that serves as a _____ electron carrier; cytochrome c is a _____ molecule that serves as a _____ electron carrier. A) hydrophobic; 2; hydrophilic; 1 B) hydrophobic; 1; hydrophilic; 1 C) hydrophilic; 2; hydrophobic; 2 D) hydrophilic; 2; hydrophobic; 1 E) hydrophobic; 1; hydrophilic; 2 Answer: A Difficulty: Easy Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway

25) Complex IV uses _____ and _____ ions to reduce oxygen to water.

A) manganese; iron B) copper; iron C) manganese; copper D) zinc; copper E) iron; zinc Answer: B

Difficulty: Medium Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway 26) How many cytochrome c molecules are oxidized by Complex IV for each molecule of oxygen that is reduced? A) 1 B) 2 C) 3 D) 4 E) it depends upon the efficiency of the electron transfer in Complex IV Answer: D Difficulty: Easy Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway

27) What free radical is thought to be commonly produced by the electron transport chain?

A) hydroxyl B) peroxyl C) superoxide D) hydrogen peroxyl E) all of the above Answer: C Difficulty: Easy Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway

28) For every two electrons transferred from NADH to oxygen, _____ protons are pumped from the matrix to the intermembrane space. A) 4 B) 6 C) 8

D) 10 E) 12 Answer: D Difficulty: Easy Section Reference: 15-2 Learning Objective: Map the path of electrons through the redox groups of the electron transport pathway

29) The imbalance of protons across the inner mitochondrial membrane is referred to as _____.

A) the protonmotive force B) the chemiosmotic force C) the electron transport force D) the ATP synthase force E) the proton gradient force Answer: A Difficulty: Easy Section Reference: 15-3 Learning Objective: Explain how cells generate and use the proton gradient 30) If the pH of the matrix is 7.7, what is the pH of the intermembrane space if the G for transport of H+ is 20 kJ/mol at 37C with  = 170 mV? A) 2.6 B) 7.1 C) 8.3 D) 12.8 E) cannot be determine Answer: B Difficulty: Hard Section Reference: 15-3 Learning Objective: Explain how cells generate and use the proton gradient

31) If the G for the oxidation of NADH by oxygen is -220 kJ/mol and the G for transport of H+ across the inner membrane is 20 kJ/mol, what is the efficiency for energy captured in the proton gradient versus energy evolved from NADH oxidation?

A) 9.1% B) 36% C) 45% D) 73% E) 91% Answer: E Difficulty: Hard Section Reference: 15-3 Learning Objective: Explain how cells generate and use the proton gradient

32) How many ATP molecules are synthesized from the oxidation of one NADH molecule?

A) 3 B) 2.5 C) 2 D) 1.5 E) 1 Answer: B Difficulty: Easy Section Reference: 15-4 Learning Objective: Describe how ATP synthase converts the protonmotive force to the chemical energy of ATP

33) How many ATP can be produced from the complete oxidation of glucose if the malate- aspartate shuttle is used? A) 2 B) 19.5 C) 28 D) 30 E) 32 Answer: E Difficulty: Hard Section Reference: 15-4 Learning Objective: Describe how ATP synthase converts the protonmotive force to the chemical energy of ATP

34) If an ATP synthase has 12 c subunits, how many protons must move through the enzyme to produce one ATP? A) 2.5 B) 3 C) 4 D) 10 E) 12 Answer: C Difficulty: Medium Section Reference: 15-4 Learning Objective: Describe how ATP synthase converts the protonmotive force to the chemical energy of ATP

35) Which subunit of ATP synthase is responsible for the catalysis of ATP formation?

A) a B) c C)  D)  E)  Answer: D Difficulty: Easy Section Reference: 15-4 Learning Objective: Describe how ATP synthase converts the protonmotive force to the chemical energy of ATP 36) Which of the following occurs when the catalytic subunit of ATP synthase is in the loose state?

A) ADP and Pi bind B) ADP and Pi are converted to ATP C) ATP is hydrolyzed D) ATP is released E) none of the above Answer: A Difficulty: Medium Section Reference: 15-4

Learning Objective: Describe how ATP synthase converts the protonmotive force to the chemical energy of ATP 37) What is the P/O ratio for the oxidation of ubiquinone if three protons are required to synthesize one ATP? A) 1 B) 1.5 C) 2 D) 3 E) 3.3 Answer: B Difficulty: Medium Section Reference: 15-4 Learning Objective: Describe how ATP synthase converts the protonmotive force to the chemical energy of ATP 38) Which of the following terms describes the effect of 2,4 dinitrophenol upon electron transport and ATP synthesis?

A) thermogenerator B) electron acceptor C) uncoupler D) inhibitor E) none of the above Answer: C Difficulty: Easy Section Reference: 15-4 Learning Objective: Describe how ATP synthase converts the protonmotive force to the chemical energy of ATP

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 16 Question type: Multiple Choice 1) What were the first organisms that had the ability to oxidize water to oxygen?

A) purple bacteria B) green sulfur bacteria C) cyanobacteria D) ferns E) green plants Answer: C Difficulty: Easy Section Reference: 16-introduction

2) What organelle is responsible for photosynthesis?

A) Golgi apparatus B) chloroplast C) endoplasmic reticulum D) peroxisome E) glyoxysome Answer: B Difficulty: Easy Section Reference: 16-1 Learning Objective: Describe the structure and purpose of pigment molecules

3) What part of the chloroplast is the site of the energy-transducing reactions of photosynthesis? A) chloroplast outer membrane B) chloroplast inner membrane C) stroma D) thylakoid lumen E) thylakoid membrane Answer: E

Difficulty: Easy Section Reference: 16-1 Learning Objective: Describe the structure and purpose of pigment molecules 4) How much energy is contained in a mole of photons with a wavelength of 490 nm?

A) 4.1  10-19 J/mol B) 2.4  10-4 J/mol C) 127 kJ/mol D) 244 kJ/mol E) 2.4  105 kJ/mol Answer: D Difficulty: Medium Section Reference: 16-1 Learning Objective: Describe the structure and purpose of pigment molecules 5) Chlorophylls and carotenoids absorb most light between ______ nm and _____ nm while reflecting most light between _____ nm.

A) 400-500; 600-700; 500-600 B) 300-400; 600-700; 400-600 C) 400-600; 700-800; 600-700 D) 300-400; 700-800; 400-700 E) none of the above Answer: A Difficulty: Easy Section Reference: 16-1 Learning Objective: Describe the structure and purpose of pigment molecules 6) Which of the following can happen when a photosynthetic pigment absorbs light?

A) energy lost as heat B) energy given off by fluorescence C) exciton transfer D) photooxidation E) all of the above Answer: E

Difficulty: Easy Section Reference: 16-1 Learning Objective: Describe the structure and purpose of pigment molecules 7) What is an assembly of antenna pigments?

A) thylakoid B) granum C) light-harvesting complex D) reaction center E) lamella Answer: C Difficulty: Easy Section Reference: 16-1 Learning Objective: Describe the structure and purpose of pigment molecules

8) Which of the following explains how a reaction center is excited? A) a reaction center can only be excited by direct absorption of a photon of light B) excitation can occur by any of the antenna pigments in direct contact with the reaction center C) excitation occurs when an antenna fluoresces so that the photon of light can be captured by a reaction center D) any antenna of the light harvesting complex can transfer an electron to the reaction center by exciton transfer E) transfer of heat energy from antenna to reaction center allows for excitation Answer: D Difficulty: Medium Section Reference: 16-1 Learning Objective: Describe the structure and purpose of pigment molecules

9) The P680 of photosystem II is composed of _____.

A) two chlorophylls B) two carotenoids C) one chlorophyll and one phycocyanin D) one chlorophyll and one carotenoid E) one carotenoid and one phycocyanin

Answer: A Difficulty: Easy Section Reference: 16-2 Learning Objective: Trace the energy transformations of the photosynthesis light reactions 10) Complete the following reaction: P680 + light → _____ → _____ A) P680*; P680- + H+ B) P680*; P680+ + eC) P680-; P680* D) P680+; P680* E) none of the above Answer: B Difficulty: Medium Section Reference: 16-2 Learning Objective: Trace the energy transformations of the photosynthesis light reactions 11) Electrons are transferred from P680 to _____, then to cytochrome b6f.

A) ubiquinone B) plastoquinone C) plastocyanin D) P700 E) NADP+ Answer: B Difficulty: Medium Section Reference: 16-2 Learning Objective: Trace the energy transformations of the photosynthesis light reactions 12) How many photons of light must be absorbed by photosystem II to produce one molecule of oxygen?

A) 1 B) 2 C) 4 D) 8 E) 16

Answer: C Difficulty: Medium Section Reference: 16-2 Learning Objective: Trace the energy transformations of the photosynthesis light reactions 13) During the oxidation of water, where do the protons go?

A) thylakoid lumen B) stroma C) space between inner and outer chloroplast membrane D) cytosol E) protons are not released but transferred to proteins for metabolic use Answer: A Difficulty: Easy Section Reference: 16-2 Learning Objective: Trace the energy transformations of the photosynthesis light reactions 14) Since the reduction potential of oxygen is +0.815 V and the reaction catalyzed by P680 is highly exergonic, which of the following is most likely the reduction potential of P680*?

A) -1.15 V B) -0.815 V C) +0.77 V D) +0.83 V E) +1.15 V Answer: E Difficulty: Medium Section Reference: 16-2 Learning Objective: Trace the energy transformations of the photosynthesis light reactions 15) Cytochrome b6f is most similar to mitochondrial _____ with the exception that electrons are passed to _____, not to cytochrome c.

A) complex I; plastocyanin B) complex I; plastoquinone C) complex III; plastocyanin D) complex III; plastoquinone E) none of the mitochondrial complexes are similar to cytochrome b6f

Answer: C Difficulty: Medium Section Reference: 16-2 Learning Objective: Trace the energy transformations of the photosynthesis light reactions 16) The active group of photosystem I is known as _____.

A) P800 B) P700 C) P660 D) P650 E) P450 Answer: B Difficulty: Easy Section Reference: 16-2 Learning Objective: Trace the energy transformations of the photosynthesis light reactions 17) Why is photosystem I unable to oxidize water?

A) it cannot transfer protons to the stroma B) it contains proteins that prevent oxygen from binding to it C) its reduction potential is exactly equal to that of oxygen D) it is a very good reducing agent E) it is not a strong enough oxidizing agent Answer: E Difficulty: Medium Section Reference: 16-2 Learning Objective: Trace the energy transformations of the photosynthesis light reactions 18) Which of the following shows the correct movement of electrons in the Z-scheme of photosynthesis?

A) H2O → P700 → plastoquinone → cytochrome b6f → plastocyanin → P680 → ferredoxin → NADP+ → B) H2O → P680 → plastocyanin → cytochrome b6f → plastoquinone → P700 → ferredoxin NADP+ → C) H2O → P680 → plastoquinone → ferredoxin → plastocyanin → P700 → cytochrome b6f

NADP+ D) H2O → P680 → plastoquinone → cytochrome b6f → plastocyanin → P700 → ferredoxin → NADP+ E) H2O → P680 → ferredoxin → plastoquinone → P700 → cytochrome b6f → plastocyanin → NADP+ Answer: D Difficulty: Hard Section Reference: 16-2 Learning Objective: Trace the energy transformations of the photosynthesis light reactions

19) Which of the following occurs during cyclic electron flow?

A) photosystem I absorbs light but not photosystem II B) protons are pumped into the lumen by cytochrome b6f C) electrons are transferred from photosystem I → ferredoxin→ cytochrome b6f → plastocyanin, then back to photosystem I D) there is no production of NADPH or oxygen E) all of the above Answer: E Difficulty: Hard Section Reference: 16-2 Learning Objective: Trace the energy transformations of the photosynthesis light reactions

20) For each molecule of oxygen generated, _____ photons are absorbed by photosystems I and II, _____ protons are transferred from stroma to lumen allowing for the production of _____ molecules of ATP. A) 4; 8; 2 B) 4; 12; 4 C) 8; 8; 4 D) 8; 12; 3 E) 8; 16; 4 Answer: D Difficulty: Hard Section Reference: 16-2 Learning Objective: Trace the energy transformations of the photosynthesis light reactions

21) Light dependent ATP production is called _____ and occurs in the _____ of chloroplasts.

A) photophosphorylation; thylakoid membrane B) photophosphorylation; inner membrane C) non-oxidative phosphorylation; thylakoid membrane D) non-oxidative phosphorylation; inner membrane E) chloroplast-associated phosphorylation; thylakoid membrane Answer: A Difficulty: Medium Section Reference: 16-2 Learning Objective: Trace the energy transformations of the photosynthesis light reactions 22) The carbon fixing reactions occur in the _____ .

A) thylakoid lumen B) thylakoid membrane C) stroma D) space between inner and outer chloroplast membrane E) cytosol Answer: C Difficulty: Easy Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle 23) In the rubisco mechanism, what performs the nucleophilic attack on carbon dioxide?

A) water B) enediolate intermediate C) enol intermediate D) a carboxylate E) none of the above Answer: B Difficulty: Medium Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle 24) Why does rubisco make up about half of the protein content in a typical chloroplast?

A) most of the enzyme is in an oxidized state, waiting for the production of NADPH to reactivate it B) it has an extremely high Km for CO2, thus a large number of enzymes increased the chance of substrate binding C) since oxygen is also a substrate, those enzymes that bind oxygen are sequestered D) it is a very inefficient enzyme, catalyzing only three reactions per second E) none of the above Answer: D Difficulty: Easy Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle

25) If carbon dioxide is used as a substrate, the major products of rubisco are _____; if oxygen is used as a substrate, the major products of rubisco are _____.

A) 2 molecules of 3-phosphoglycerate; 2-phosphoglycolate and 3-phosphoglycerate B) 2 molecules of 3-phosphoglycerate; glyoxylate and 3-phosphoglycerate C) 3-phosphoglycerate and glyceraldehyde-3-phosphate; 2-phosphoglycolate and 3phosphoglycerate D) 3-phosphoglycerate and glyceraldehyde-3-phosphate; glyoxylate and 3-phosphoglycerate E) none of the above Answer: A Difficulty: Medium Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle

26) Which of the following describes photorespiration?

A) consumes ATP B) consumes NADPH C) produces CO2 D) consumes oxygen E) all of the above Answer: E Difficulty: Easy Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle

27) In C4 plants, CO2 (as bicarbonate) is condensed with _____ to yield _____ in the mesophyll cells.

A) pyruvate; oxaloacetate B) 3-phosphoglycerate; malate C) lactate; fumarate D) phosphoenolpyruvate; oxaloacetate E) oxaloacetate; -ketoglutarate Answer: D Difficulty: Medium Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle 28) In C4 plants, _____ is found in the mesophyll cells to capture CO2 while _____ is found in the bundle sheath cells to release CO2.

A) phosphoenolpyruvate carboxylase; malic enzyme B) pyruvate carboxylase; malic enzyme C) pyruvate carboxylase; -ketoglutarate dehydrogenase D) pyruvate kinase; pyruvate dehydrogenase E) none of the above Answer: A Difficulty: Hard Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle 29) The products of the light reactions, ATP and NADPH, are used by ______ and ______, respectively.

A) rubisco; glyceraldehyde-3-phosphate dehydrogenase B) phosphoglycerate kinase; glyceraldehyde-3-phosphate dehydrogenase C) phosphoribulokinase; 3-phosphoglycerate dehydrogenase D) phosphofructokinase; pyruvate dehydrogenase E) phosphoglycerate kinase; 3-phosphoglycerate dehydrogenase Answer: B Difficulty: Medium

Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle 30) The Z-scheme of photosynthesis produces a 3:2 ratio of ATP:NADPH. How does a C4 plant compensate for the greater ATP requirement created by the C4 pathway?

A) no changes need to be made since there is more ATP available from the light reactions than actually needed for carbon fixation B) no cyclic photophosphorylation can occur C) more cyclic photophosphorylation must occur D) oxygen production must be increased at photosystem II E) oxygen production must be decreased at photosystem II Answer: C Difficulty: Hard Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle

31) Regeneration of the rubisco substrate, ribulose-1,5-bisphosphate involves which of the following sugars?

A) a tetrose-phosphate B) a pentose-phosphate C) a hexose-phosphate D) a heptose-phosphate E) all of the above Answer: E Difficulty: Easy Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle 32) The production of one molecule of glucose requires _____.

A) 6 CO2, 9 ATP, 6 NADPH B) 6 CO2, 18 ATP, 12 NADPH C) 6 CO2, 6 ATP, 9 NADPH D) 6 CO2, 12 ATP, 18 NADPH E) 3 CO2, 9 ATP, 6 NADPH Answer: B

Difficulty: Medium Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle 33) What causes carboxylation of a critical lysine residue that coordinates Mg2+ in the rubisco active site to occur?

A) when ATP levels are high due to high activity of the light reactions B) when NADPH level are high due to high activity of the light reactions C) when pH is low due to low activity of the light reactions D) when pH is high due to high activity of the light reactions E) when reduced ferredoxin is high due to high activity of the light reactions Answer: D Difficulty: Medium Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle

34) The Z-scheme of photosynthesis produces a 3:2 ratio of ATP:NADPH. How does a plant compensate when starch or sucrose is being synthesized?

A) no changes need to be made since there is more ATP available from the light reactions than actually needed for carbon fixation B) no cyclic photophosphorylation can occur C) more cyclic photophosphorylation must occur D) more NADPH must be made E) none of the above Answer: C Difficulty: Hard Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle

35) What two substrates are needed to produce sucrose in plants? A) UDP-glucose and fructose-6-phosphate B) UDPfructose and glucose-6-phosphate C) glucose and fructose1,6-bisphosphate D) UDP-glucose-6-phosphate and fructose E) UDP-glucose and fructose-1,6-bisphosphate

Answer: A Difficulty: Medium Section Reference: 16-3 Learning Objective: Describe the steps of carbon fixation by the Calvin cycle

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 17 Question type: Multiple Choice 1) Of the major lipoproteins, _____ are highest in cholesterol and cholesterol esters while _____ are highest in triacylglycerols. A) chylomicrons; HDL B) VLDL; LDL C) LDL; VLDL D) LDL; chylomicrons E) HDL; VLDL Answer: D Difficulty: Medium Section Reference: 17-intro Learning Objective:

2) To oxidize the fatty acids in a triacylglycerol, what must occur first?

A) fatty acid activation B) lipolysis C) transport into the mitochondria D) oxidation of a carbon-carbon single bond to an alkene E) none of the above Answer: B Difficulty: Medium Section Reference: 17-1 Learning Objective: Summarize the enzymes and chemical reactions involved in oxidizing different types of fatty acids

3) The hydrolysis of triacylglycerols stored in adipose tissue is catalyzed by the enzyme _____.

A) hormone-sensitive lipase B) lipoprotein lipase C) albumin-associated lipase D) chylomicron lipase

E) adipocyte lipase Answer: A Difficulty: Easy Section Reference: 17-1 Learning Objective: Summarize the enzymes and chemical reactions involved in oxidizing different types of fatty acids 4) What is the product of fatty acid activation?

A) acyladenylate B) pyrophosphate C) acyl-CoA D) acyl ester E) acyl-carnitine Answer: C Difficulty: Easy Section Reference: 17-1 Learning Objective: Summarize the enzymes and chemical reactions involved in oxidizing different types of fatty acids 5) What transport system moves activated fatty acids from the cytosol to the mitochondrial matrix?

A) triacylglycerol shuttle B) glycerol phosphate shuttle C) acyl adenylate shuttle D) lipoprotein shuttle E) carnitine shuttle Answer: E Difficulty: Easy Section Reference: 17-1 Learning Objective: Summarize the enzymes and chemical reactions involved in oxidizing different types of fatty acids 6) Each round of -oxidation of a saturated fatty acyl-CoA produces _____.

A) 1 NADH, 1 QH2, 1 CO2, 1 acetyl-CoA

B) 1 NADH, 1 QH2, 1 acetyl-CoA C) 1 NADH, 1 QH2, 2 acetyl-CoA D) 1 NADH, 1 QH2, 1 H2O, 1 acetyl-CoA E) 2 NADH, 1 QH2, 1 acetyl-CoA Answer: B Difficulty: Medium Section Reference: 17-1 Learning Objective: Summarize the enzymes and chemical reactions involved in oxidizing different types of fatty acids

7) What are the -oxidation products of stearic acid, a saturated fatty acid with 18 carbons?

A) 9 NADH, 9 QH2, 9 acetyl-CoA B) 9 NADH, 8 QH2, 9 acetyl-CoA C) 8 NADH, 9 QH2, 9 acetyl-CoA D) 8 NADH, 8 QH2, 9 acetyl-CoA E) 8 NADH, 7 QH2, 9 acetyl-CoA Answer: D Difficulty: Medium Section Reference: 17-1 Learning Objective: Summarize the enzymes and chemical reactions involved in oxidizing different types of fatty acids 8) In the -oxidation pathway, the oxidation occurs at carbon _____ with the acetyl group that becomes acetyl-CoA derived from the _____ end of the fatty acid.

A) 1; carbonyl B) 1; methyl C) 2; carbonyl D) 2; methyl E) 3; carbonyl Answer: E Difficulty: Medium Section Reference: 17-1 Learning Objective: Summarize the enzymes and chemical reactions involved in oxidizing different types of fatty acids

9) How many ATP can be produced by the complete oxidation of palmitoleic acid, a 16-carbon monounsaturated fatty acid, considering that the fatty acid must first be activated?

A) 26.5 B) 96.5 C) 104.5 D) 106.5 E) none of the above Answer: C Difficulty: Hard Section Reference: 17-1 Learning Objective: Summarize the enzymes and chemical reactions involved in oxidizing different types of fatty acids 10) What coenzyme is required for the complete -oxidation of a polyunsaturated fatty acid?

A) NADPH B) NADP+ C) NADH D) FADH2 E) all of the above Answer: A Difficulty: Hard Section Reference: 17-1 Learning Objective: Summarize the enzymes and chemical reactions involved in oxidizing different types of fatty acids 11) During -oxidation of an odd-chain fatty acid, the last three carbon atoms from the oxidized fatty acid enter the citric acid cycle as _____.

A) propionyl-CoA B) methylmalonyl-CoA C) succinyl-CoA D) succinate E) fumarate Answer: C Difficulty: Medium Section Reference: 17-1

Learning Objective: Summarize the enzymes and chemical reactions involved in oxidizing different types of fatty acids 12) During -oxidation in the peroxisome, what reoxidizes the enzyme-bound FADH2 during the first oxidation of the pathway?

A) H2O2 B) O2 C) NAD+ D) FMN E) none of the above Answer: B Difficulty: Medium Section Reference: 17-1 Learning Objective: Summarize the enzymes and chemical reactions involved in oxidizing different types of fatty acids

13) Which of the following types of fatty acids would be oxidized exclusively in the peroxisome instead of the mitochondria?

A) short-chain saturated fatty acids B) very long-chain saturated fatty acids C) monounsaturated fatty acids D) polyunsaturated fatty acids E) branched-chain fatty acids Answer: E Difficulty: Medium Section Reference: 17-1 Learning Objective: Summarize the enzymes and chemical reactions involved in oxidizing different types of fatty acids 14) Fatty acid oxidation occurs in the _____; fatty acid synthesis occurs in the _____.

A) mitochondria; cytosol B) mitochondria; lysosome C) lysosome; Golgi apparatus D) cytosol; Golgi apparatus E) mitochondria; endoplasmic reticulum

Answer: A Difficulty: Easy Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis 15) The portion of the acyl carrier protein that activates the growing fatty acid is similar to the structure of _____.

A) biotin B) thiamine pyrophosphate C) tetrahydrobiopterin D) coenzyme A E) folic acid Answer: D Difficulty: Easy Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis 16) The activation of acetyl-CoA for fatty acid synthesis is achieved by converting the acetylCoA into _____.

A) propionyl-CoA B) malonyl-CoA C) acetoacetyl-CoA D) HMG-CoA E) -hydroxybutyryl-CoA Answer: B Difficulty: Medium Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis 17) Acetyl-CoA carboxylase requires the coenzyme _____ and _____ as an energy source.

A) FADH2; acyl-CoA hydrolysis B) NADPH; GTP

C) biotin; ATP D) coenzyme A; GTP E) thiamine pyrophosphate; acyl-CoA hydrolysis Answer: C Difficulty: Medium Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis

18) What molecule is able to move across the mitochondrial membrane and is thus used to “transfer” acetyl-CoA from the mitochondria to the cytosol?

A) acetate B) oxaloacetate C) -ketoglutarate D) citrate E) succinate Answer: D Difficulty: Easy Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis 19) If a reaction that included all of the enzymes involved in fatty acid synthesis was supplied with excess ATP, NADPH, acetyl-CoA and 14CO2 (where the carbon was a 14C-label), where would the labeled carbon appear in the finished fatty acid?

A) odd-numbered carbons B) even-numbered carbons C) every third carbon D) every fifth carbon E) no carbons would be labeled Answer: E Difficulty: Hard Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis

20) In fatty acid synthesis, _____ catalyzes the reverse reaction of _____ in -oxidation.

A) 3-ketoacyl-ACP synthase; acyl-CoA dehydrogenase B) 3-ketoacyl-ACP reductase; 3-hydroxyacyl-CoA dehydrogenase C) 3-hydroxyacyl-ACP dehydrase; enoyl-CoA hydratase D) enoyl-ACP reductase; thiolase E) transacylase; enoyl-CoA hydratase Answer: C Difficulty: Hard Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis

21) When a growing fatty acid is not attached to the ACP, it is attached to a _____ residue of the fatty acid synthase complex.

A) Cys B) Ser C) Tyr D) Glu E) His Answer: A Difficulty: Easy Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis 22) What are the energy requirements for the synthesis of one molecule of palmitate from eight molecules of acetyl-CoA in the mitochondria?

A) 16 NADPH, 15 ATP B) 16 NADPH, 8 ATP C) 16 NADPH, 7 ATP D) 14 NADPH, 15 ATP E) 14 NADPH, 7 ATP Answer: D Difficulty: Hard

Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis 23) What pathway supplies the bulk of the NADPH needed for fatty acid synthesis in mammals?

A) citric acid cycle B) pentose phosphate pathway C) glycolysis D) light reactions of photosynthesis E) all of the above Answer: B Difficulty: Medium Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis

24) What enzymes are required to make fatty acids containing 22 or 24 carbons?

A) elongases B) reductase C) desaturase D) hydratase E) malonyl-CoA ligase Answer: A Difficulty: Easy Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis

25) Which enzyme is the most important control point for fatty acid synthesis?

A) ATP-citrate lyase B) transacylase C) 3-ketoacyl-ACP reductase D) 3-hydroxyacyl-ACP dehydrase E) acetyl-CoA carboxylase Answer: E

Difficulty: Easy Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis 26) Ketone bodies are produced in the _____ and used by the _____ only under conditions such as a prolonged fast. A) liver; heart B) liver; brain C) liver; skeletal muscle D) kidneys; heart E) kidneys; brain Answer: B Difficulty: Medium Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis

27) The conversion of 3-hydroxybutyrate to two molecules of acetyl-CoA produces 1 NADH and consumes 1 equivalent of ATP. What is the net ATP yield from the complete oxidation of 3- hydroxybutyrate? A) 1.5 B) 11.5 C) 13.5 D) 21.5 E) 23.5 Answer: D Difficulty: Hard Section Reference: 17-2 Learning Objective: Summarize the enzymes and chemical reactions of fatty acid and ketone body synthesis

28) The synthesis of triacylglycerols involves the addition of acyl groups to glycerol-3phosphate. What is the source of the acyl groups?

A) free fatty acid

B) fatty acid attached to the acyl carrier protein C) fatty acyladenylate D) acyl-carnitine E) fatty acyl-CoA Answer: E Difficulty: Medium Section Reference: 17-3 Learning Objective: Describe the synthesis of triacylglycerols, phospholipids, and cholesterol

29) Which of the following best describes the order for the conversion of glycerol-3-phosphate into a triacylglycerol?

A) 1 phosphatase reaction then 3 acyltransferase reactions B) 1 acyltransferase reaction, 1 phosphatase reaction, then 2 more acyltransferase reactions C) 2 acyltransferase reactions, 1 phosphatase reaction, then 1 acyltransferase reaction D) 3 acyltransferase reactions then 1 phosphatase reaction E) 1 acyltransferase reaction, 1 phosphatase reaction, 1 acyltransferase reaction, 1 phosphatase reaction, then 1 acyltransferase reaction Answer: C Difficulty: Hard Section Reference: 17-3 Learning Objective: Describe the synthesis of triacylglycerols, phospholipids, and cholesterol

30) What is used to activate phosphoethanolamine prior to reaction with a diacylglycerol?

A) ATP B) CTP C) GTP D) TTP E) UTP Answer: B Difficulty: Medium Section Reference: 17-3 Learning Objective: Describe the synthesis of triacylglycerols, phospholipids, and cholesterol 31) Which of the following best describes the sequence of events for the synthesis of phosphatidylcholine?

A) phosphocholine condenses with glycerol-3-phosphate, then two fatty acids are added B) CDP-choline reacts with a monoacylglycerol followed by fatty acid addition C) a diacylglycerol pyrophosphate reacts with choline D) CDP-choline reacts with a diacylglycerol E) none of the above Answer: D Difficulty: Hard Section Reference: 17-3 Learning Objective: Describe the synthesis of triacylglycerols, phospholipids, and cholesterol

32) Which of the following explains how phosphatidylserine is synthesized?

A) serine displaces the ethanolamine from a phosphatidylethanolamine B) serine reacts with a diacylglycerol pyrophosphate C) CDP-serine reacts with diacylglycerol D) serine reacts with a CDP-diacylglycerol E) the ethanolamine group of phosphatidylethanolamine is carboxylated to form serine Answer: A Difficulty: Medium Section Reference: 17-3 Learning Objective: Describe the synthesis of triacylglycerols, phospholipids, and cholesterol 33) What enzyme is the major control point of cholesterol synthesis in humans?

A) HMG-CoA synthase B) HMG-CoA lyase C) HMG-CoA reductase D) thiolase E) isopentenyl pyrophosphate synthase Answer: C Difficulty: 1 Section Reference: 17-3 Learning Objective: Describe the synthesis of triacylglycerols, phospholipids, and cholesterol 34) What mechanism is used to control whether HMG-CoA is used for ketone body synthesis or for cholesterol synthesis?

A) control of HMG-CoA lyase versus HMG-CoA reductase B) control of NADPH versus acetyl-CoA levels C) control of NADPH:NAD+ levels D) depletion of products influences where HMG-CoA will be shunted E) ketone bodies are synthesized in the mitochondria; cholesterol is synthesized in the liver Answer: E Difficulty: Medium Section Reference: 17-3 Learning Objective: Describe the synthesis of triacylglycerols, phospholipids, and cholesterol

35) What class of lipid is squalene, the precursor to cholesterol?

A) isoprenoid B) fatty acid C) steroid D) wax E) triacylglycerol Answer: A Difficulty: Easy Section Reference: 17-3 Learning Objective: Describe the synthesis of triacylglycerols, phospholipids, and cholesterol 36) Which of the following commonly occurs before cholesterol is packaged into a VLDL? A) oxidation to increase water solubility B) esterification with a fatty acid C) phosphorylation by ATP D) hydration of the alkene E) all of the above may occur Answer: B Difficulty: Medium Section Reference: 17-3 Learning Objective: Describe the synthesis of triacylglycerols, phospholipids, and cholesterol 37) Cholesterol is converted into _____, a molecule that aids in the absorption of dietary lipids.

A) aldosterone B) cortisol C) -estradiol D) progesterone E) cholate Answer: E Difficulty: Medium Section Reference: 17-3 Learning Objective: Describe the synthesis of triacylglycerols, phospholipids, and cholesterol

38) Which of the lipoproteins is responsible for removing cholesterol from cells?

A) chylomicron B) VLDL C) LDL D) HDL E) VHDL Answer: D Difficulty: Easy Section Reference: 17-3 Learning Objective: Describe the synthesis of triacylglycerols, phospholipids, and cholesterol

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 18 Question type: Multiple Choice 1) How many ATP and electrons are required for the reduction of one molecule of nitrogen to two molecules of ammonia in the reaction catalyzed by nitrogenase? A) 8 ATP and 8 electrons B) 16 ATP and 8 electrons C) 16 ATP and 16 electrons D) 8 ATP and 16 electrons E) 16 ATP and 6 electrons Answer: B Difficulty: Medium Section Reference: 18-1 Learning Objective: Describe the chemical reactions of nitrogen fixation and assimilation

2) Which of the following are required by nitrogenase to carry out the reduction of nitrogen?

A) an iron-molybdenum cofactor B) iron-sulfur centers C) a strong reducing agent such as ferredoxin D) the absence of oxygen E) all of the above Answer: E Difficulty: Medium Section Reference: 18-1 Learning Objective: Describe the chemical reactions of nitrogen fixation and assimilation

3) In the process of nitrification, nitrate reductase converts _____ into _____.

A) nitrate; nitrogen B) nitrate; ammonia C) nitrate; nitrite D) nitrate; nitric oxide E) nitrogen; nitrate

Answer: C Difficulty: Medium Section Reference: 18-1 Learning Objective: Describe the chemical reactions of nitrogen fixation and assimilation 4) What enzyme is responsible for the incorporation of ammonia from nitrogen fixation into organic molecules?

A) glutamine synthetase B) glutamine synthase C) glutamate synthetase D) glutamate synthase E) transaminase Answer: A Difficulty: Easy Section Reference: 18-1 Learning Objective: Describe the chemical reactions of nitrogen fixation and assimilation 5) Given the following reaction, what is the missing product of the net reaction of glutamine synthetase and glutamate synthase? -ketoglutarate + NH+ 4 + NADPH + ATP → NADP+ + ADP + Pi + _____ A) aspartate B) asparagine C) glutamate D) glutamine E) none of the above Answer: C Difficulty: Easy Section Reference: 18-1 Learning Objective: Describe the chemical reactions of nitrogen fixation and assimilation 6) What are the products of the following transamination reaction? -ketoglutarate + alanine

_____ + _____

A) aspartate; oxaloacetate B) glutamate; oxaloacetate C) aspartate; pyruvate D) glutamate; pyruvate E) none of the above Answer: D Difficulty: Medium Section Reference: 18-1 Learning Objective: Describe the chemical reactions of nitrogen fixation and assimilation

7) What amino acid is attached to the pyridoxal-5-phosphate in a typical transaminase?

A) Ser B) His C) Arg D) Gln E) Lys Answer: E Difficulty: Easy Section Reference: 18-1 Learning Objective: Describe the chemical reactions of nitrogen fixation and assimilation 8) When the transaminase enzyme is in the _____ form, it will only react with _____.

A) pyridoxal; -keto acid B) pyridoxal; -amino acid C) pyridoxamine; -amino acid D) pyridoxal; -keto acid E) pyridoxamine; -amino acid Answer: B Difficulty: Easy Section Reference: 18-1 Learning Objective: Describe the chemical reactions of nitrogen fixation and assimilation 9) Which of the following nonessential amino acids is correctly paired with the essential amino acid that is required for its synthesis?

A) Phe: Trp B) Cys: Met C) Ser: Gly D) Asp: Glu E) His: Gln Answer: B Difficulty: Hard Section Reference: 18-2 Learning Objective: Summarize the pathways for synthesizing the essential and nonessential amino acids

10) Which of the following citric acid cycle intermediates can be converted to aspartate via transamination?

A) succinate B) fumarate C) -ketoglutarate D) citrate E) oxaloacetate Answer: E Difficulty: Easy Section Reference: 18-2 Learning Objective: Summarize the pathways for synthesizing the essential and nonessential amino acids 11) Which of the following glycolytic intermediates is the common precursor to serine, cysteine and glycine?

A) 3-phosphoglycerate B) pyruvate C) fructose-6-phosphate D) dihydroxyacetone phosphate E) glyceraldehyde-3-phosphate Answer: A Difficulty: Easy Section Reference: 18-2 Learning Objective: Summarize the pathways for synthesizing the essential and nonessential amino acids

12) Which of the following amino acids is properly paired with the amino acid from which it is derived?

A) Gln: Asp B) Pro: Ala C) Arg: Lys D) Tyr: Phe E) Ser: Cys Answer: D Difficulty: Medium Section Reference: 18-2 Learning Objective: Summarize the pathways for synthesizing the essential and nonessential amino acids

13) What coenzyme is required for the conversion of serine to glycine?

A) pyridoxal phosphate B) lipoic acid C) tetrahydrofolate D) biotin E) cobalamin Answer: C Difficulty: Easy Section Reference: 18-2 Learning Objective: Summarize the pathways for synthesizing the essential and nonessential amino acids 14) What form of the folate coenzyme is required for the conversion of homocysteine to methionine?

A) methyl-tetrahydrofolate B) methylene-tetrahydrofolate C) methenyl-tetrahydrofolate D) formyl-tetrahydrofolate E) dihydrofolate Answer: A Difficulty: Medium

Section Reference: 18-2 Learning Objective: Summarize the pathways for synthesizing the essential and nonessential amino acids 15) Which of the following amino acids requires chorismate for its synthesis?

A) Met B) Lys C) Ile D) Trp E) none of the above Answer: D Difficulty: Medium Section Reference: 18-2 Learning Objective: Summarize the pathways for synthesizing the essential and nonessential amino acids 16) Which of the following amino acids cannot be produced in a plant that has been treated with glyphosate?

A) Cys B) Phe C) Leu D) Arg E) Pro Answer: B Difficulty: Medium Section Reference: 18-2 Learning Objective: Summarize the pathways for synthesizing the essential and nonessential amino acids 17) What enzyme catalyzes the conversion of phenylalanine to tyrosine?

A) phenylalanine hydrolase B) phenylalanine desaturase C) phenylalanine oxidase D) phenylalanine decarboxylase E) phenylalanine hydroxylase

Answer: E Difficulty: Easy Section Reference: 18-2 Learning Objective: Summarize the pathways for synthesizing the essential and nonessential amino acids 18) What amino acid is the precursor for the neurotransmitters epinephrine and norepinephrine?

A) tryptophan B) serine C) tyrosine D) aspartate E) glutamate Answer: C Difficulty: Easy Section Reference: 18-2 Learning Objective: Summarize the pathways for synthesizing the essential and nonessential amino acids

19) Which of the following neurotransmitters is correctly paired with the amino acid from which it is synthesized?

A) dopamine: tyrosine B) -aminobutyric acid: glutamate C) serotonin: tryptophan D) epinephrine: tyrosine E) all of the above Answer: E Difficulty: Medium Section Reference: 18-2 Learning Objective: Summarize the pathways for synthesizing the essential and nonessential amino acids

20) The molecule _____ which is synthesized from _____, stimulate vasodilation.

A) nitric oxide; arginine B) nitrous oxide; arginine C) nitric oxide; citrulline

D) nitrous oxide; citrulline E) none of the above Answer: A Difficulty: Medium Section Reference: 18-2 Learning Objective: Summarize the pathways for synthesizing the essential and nonessential amino acids

21) What coenzyme is used when inosine monophosphate is oxidized to xanthosine monophosphate?

A) NADPH B) NADP+ C) NADH D) NAD+ E) FAD Answer: D Difficulty: Easy Section Reference: 18-3 Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides

22) Which of the following amino acids is a source of both carbon and nitrogen for IMP? A) Glu B) Gln C) Gly D) Asp E) Asn Answer: C Difficulty: Medium Section Reference: 18-3 Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides

23) The conversion of IMP to AMP requires _____; the conversion of IMP to GMP requires _____.

A) Gln; Glu B) Asp; Gln C) Asn; Asp D) Glu; Asn E) Asp; Glu Answer: B Difficulty: Medium Section Reference: 18-3 Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides

24) Which of the following correctly describes the general synthesis of purine nucleotides?

A) The basic ring structure, orotate, is synthesized and then linked to PRPP B) The basic ring structure, orotate, is synthesized stepwise on PRPP C) The basic ring structure, inosine, is synthesized and then linked to PRPP D) The basic ring structure, inosine, is synthesized stepwise on PRPP E) none of the above Answer: D Difficulty: Medium Section Reference: 18-3 Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides

25) The energy for the conversion of IMP to GMP is supplied by _____. A) ATP B) CTP C) GTP D) TTP E) UTP Answer: A Difficulty: Easy Section Reference: 18-3 Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides

26) What step controls the activity of both purine and pyrimidine synthesis?

A) conversion of IMP to adenylosuccinate for AMP production B) conversion of IMP to xanthosine monophosphate for GMP production C) conversion of ribose-5-phosphate to 5-phosphoribosyl pyrophosphate D) conversion of UTP to CTP E) ribonucleotide reductase Answer: C Difficulty: Easy Section Reference: 18-3 Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides

27) Which of the following amino acids is a source of both carbon and nitrogen for UMP? A) Glu B) Gln C) Gly D) Asp E) Asn Answer: D Difficulty: Easy Section Reference: 18-3 Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides

28) What enzyme is responsible for the conversion of nucleotides to deoxynucleotides?

A) ribonucleotide deoxidase B) ribonucleotide dehydratase C) ribonucleotide dehydrogenase D) ribonucleotide oxidase E) ribonucleotide reductase Answer: E Difficulty: Easy Section Reference: 18-3

Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides 29) In the mechanism of ribonucleotide reductase, a _____ is generated at C3 to stabilize the _____ that is formed at C2.

A) radical; carbocation B) radical; carbanion C) carbocation; radical D) carbanion; radical E) carbanion; carbocation Answer: A Difficulty: Hard Section Reference: 18-3 Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides

30) What molecule is used to reduce ribonucleotide reductase back to its catalytically active state?

A) NADH B) NADPH C) thioredoxin D) ferredoxin E) FADH2 Answer: C Difficulty: Easy Section Reference: 18-3 Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides 31) What nucleotide is methylated to produce dTMP? A) dAMP B) dCMP C) dGMP D) dUMP E) both dCMP and dUMP can be converted to dTMP

Answer: D Difficulty: Easy Section Reference: 18-3 Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides

32) Which of the following organisms excrete uric acid?

A) birds B) insects C) reptiles D) primates E) all of the above Answer: E Difficulty: Easy Section Reference: 18-3 Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides

33) The disease gout is characterized by high levels of _____, which forms crystal deposits of _____, resulting in painful joints A) urea; uric acid B) uric acid; sodium urate C) sodium urate; urea D) uric acid; urea E) none of the above Answer: B Difficulty: Easy Section Reference: 18-3 Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides

34) Which of the following is formed as a result of pyrimidine metabolism?

A) alanine B) aspartate C) asparagine

D) glycine E) -alanine Answer: E Difficulty: Easy Section Reference: 18-3 Learning Objective: Describe the key reactions in the synthesis and degradation of nucleotides and deoxynucleotides

35) Which of the following amino acids is exclusively ketogenic?

A) Leu B) Val C) Phe D) Arg E) Thr Answer: A Difficulty: Easy Section Reference: 18-4 Learning Objective: Summarize the pathways for degrading amino acids 36) What are the products of the glycine cleavage system?

A) formyl-tetrahydrofolate, ammonia and carbon dioxide B) methylene-tetrahydrofolate, ammonia and carbon dioxide C) methyl-tetrahydrofolate, ammonia and carbon dioxide D) methylene-tetrahydrofolate and carbamoyl phosphate E) methyl-tetrahydrofolate and carbamoyl phosphate Answer: B Difficulty: Medium Section Reference: 18-4 Learning Objective: Summarize the pathways for degrading amino acids 37) Threonine is considered both ketogenic and glucogenic because it is converted to _____ and _____.

A) pyruvate; acetyl-CoA B) ammonia; acetoacetate

C) carbamoyl phosphate; acetoacetate D) glycine; acetyl-CoA E) glycine; glutaryl-CoA Answer: D Difficulty: Hard Section Reference: 18-4 Learning Objective: Summarize the pathways for degrading amino acids

38) What type of reaction is used to deaminate most amino acids?

A) ATP-dependent ligation B) transamination C) oxidation D) condensation E) reduction Answer: B Difficulty: Easy Section Reference: 18-4 Learning Objective: Summarize the pathways for degrading amino acids 39) Degradation to pyruvate makes an amino acid _____; degradation to acetoacetate makes an amino acid _____.

A) glucogenic; glucogenic B) glucogenic; glucogenic and ketogenic C) glucogenic; ketogenic D) ketogenic; glucogenic E) ketogenic; ketogenic Answer: C Difficulty: Easy Section Reference: 18-4 Learning Objective: Summarize the pathways for degrading amino acids 40) What coenzyme is required by phenylalanine hydroxylase?

A) NADPH B) dihydrofolate

C) ferredoxin D) FADH2 E) tetrahydrobiopterin Answer: E Difficulty: Easy Section Reference: 18-4 Learning Objective: Summarize the pathways for degrading amino acids 41) The enzyme _____ is missing in phenylketonuria while _____ is missing in alkaptonuria.

A) tyrosine transaminase; phenylalanine hydroxylase B) phenylalanine hydroxylase; p-hydroxy-phenylpyruvate dioxygenase C) phenylalanine hydroxylase; homogentisate oxidase D) p-hydroxy-phenylpyruvate dioxygenase; homogentisate oxidase E) homogentisate oxidase; tyrosine transaminase Answer: C Difficulty: Hard Section Reference: 18-4 Learning Objective: Summarize the pathways for degrading amino acids

42) The amino acids metabolized by the branched chain keto acid dehydrogenase complex are _____.

A) Val, Leu and Ile B) Thr, Val and Pro C) Pro, Leu and Met D) Ile, Thr and Pro E) none of the above Answer: A Difficulty: Easy Section Reference: 18-4 Learning Objective: Summarize the pathways for degrading amino acids 43) In high levels, ammonia is toxic to _____ cells.

A) kidney B) cardiac C) liver

D) nerve E) intestinal Answer: D Difficulty: Easy Section Reference: 18-5 Learning Objective: Describe the chemical reactions of the urea cycle

44) Glutamate undergoes a(n) _____, catalyzed by glutamate dehydrogenase, to yield ketoglutarate, NADH and _____.

A) reductive deamination; water B) oxidative deamination; ammonia C) reductive amination; water D) oxidative amination; ammonia E) none of the above Answer: B Difficulty: Medium Section Reference: 18-5 Learning Objective: Describe the chemical reactions of the urea cycle

45) In the mechanism of carbamoyl phosphate synthetase, what undergoes nucleophilic attack by ammonia?

A) the carbonyl group of carboxyphosphate B) the terminal phosphate of ATP C) the middle phosphate of ATP D) the carbonyl group of carbamate E) the phosphate of carboxyphosphate Answer: A Difficulty: Hard Section Reference: 18-5 Learning Objective: Describe the chemical reactions of the urea cycle 46) Which of the following contains the correct sequence of reactants for carbamoyl phosphate synthetase?

A) ATP and ammonia, then bicarbonate, then ATP

B) ATP and ammonia, then ATP, then bicarbonate C) ATP and bicarbonate, then ammonia, then ATP D) ATP and bicarbonate, then ATP, then ammonia E) ammonia and bicarbonate, then two ATP molecules Answer: C Difficulty: Hard Section Reference: 18-5 Learning Objective: Describe the chemical reactions of the urea cycle

47) Which urea cycle intermediate reacts with carbamoyl phosphate?

A) citrulline B) aspartate C) argininosuccinate D) arginine E) ornithine Answer: E Difficulty: Easy Section Reference: 18-5 Learning Objective: Describe the chemical reactions of the urea cycle

48) Based upon the following, what is the net ATP production for the synthesis of one molecule of urea in the urea cycle? Consider that one nitrogen atom comes from glutamate dehydrogenase and the other comes from aspartate.

The conversion of fumarate to oxaloacetate gives 1 NADH (oxaloacetate is transaminated to aspartate) Carbamoyl phosphate synthesis requires 2 ATP equivalents Argininosuccinate synthesis requires 2 ATP equivalents Glutamate dehydrogenase produces 1 NADH A) -4 ATP B) -1.5 ATP C) -1 ATP D) +1 ATP E) +3 ATP Answer: D Difficulty: Hard

Section Reference: 18-5 Learning Objective: Describe the chemical reactions of the urea cycle 49) What enzyme associated with the urea cycle enzyme is activated by N-acetylglutamate?

A) carbamoyl phosphate synthetase B) glutamate dehydrogenase C) argininosuccinate synthetase D) arginase E) ornithine transcarbamoylase Answer: A Difficulty: Easy Section Reference: 18-5 Learning Objective: Describe the chemical reactions of the urea cycle

50) What do birds excrete as nitrogen waste instead of urea?

A) asparagine B) uric acid C) carbamoyl phosphate D) citrulline E) arginine Answer: B Difficulty: Easy Section Reference: 18-5 Learning Objective: Describe the chemical reactions of the urea cycle

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 19 Question type: Multiple Choice 1) Which of the following metabolic pathways is carried out only in the liver?

A) glycogen storage B) ketogenesis C) fatty acid synthesis D) triacylglycerol synthesis E) pentose phosphate pathway Answer: B Difficulty: Easy Section Reference: 19-1 Learning Objective: Summarize the metabolic functions of liver, kidney, muscle, and adipose tissue

2) Which of the following metabolic pathways occurs exclusively in the cytosol?

A) citric acid cycle B) ketogenesis C) urea cycle D) amino acid degradation E) fatty acid synthesis Answer: E Difficulty: Medium Section Reference: 19-1 Learning Objective: Summarize the metabolic functions of liver, kidney, muscle, and adipose tissue

3) Which of the following pathways is active in the muscle only during the well-fed state?

A) glycolysis B) fatty acid oxidation C) glycogen storage D) ketone body synthesis E) fatty acid synthesis

Answer: C Difficulty: Easy Section Reference: 19-1 Learning Objective: Summarize the metabolic functions of liver, kidney, muscle, and adipose tissue 4) Adipocytes convert glucose into fatty acids and _____.

A) glycerol B) cholesterol C) ketone bodies D) lactate E) ribose-5-phosphate Answer: A Difficulty: Medium Section Reference: 19-1 Learning Objective: Summarize the metabolic functions of liver, kidney, muscle, and adipose tissue 5) The kidney has a small amount of gluconeogenic activity. Which of the following explains the source of carbon for gluconeogenesis?

A) conversion of aspartate into oxaloacetate B) conversion of citrate into acetyl-CoA and oxaloacetate C) conversion of odd-chain fatty acids into succinyl-CoA D) conversion of alanine into pyruvate E) conversion of glutamine into glutamic acid, then to -ketoglutarate Answer: E Difficulty: Hard Section Reference: 19-1 Learning Objective: Summarize the metabolic functions of liver, kidney, muscle, and adipose tissue 6) What metabolite is used in unusually high amounts by cancerous tumors and is thus often used as a means to visualize cancerous tissue?

A) lactate B) glutamine C) glucose D) ketone bodies E) very long chain fatty acids

Answer: C Difficulty: Medium Section Reference: 19-1 Learning Objective: Summarize the metabolic functions of liver, kidney, muscle, and adipose tissue

7) In a variation of the Cori cycle, what amino acid is transported from the muscle to the liver?

A) glycine B) glutamate C) aspartate D) alanine E) glutamine Answer: D Difficulty: Easy Section Reference: 19-1 Learning Objective: Summarize the metabolic functions of liver, kidney, muscle, and adipose tissue

8) Under anaerobic conditions, _____ is produced in the muscle and is then used by the liver for _____.

A) glycerol; triacylglycerol synthesis B) lactate; gluconeogenesis C) citrate; fatty acid synthesis D) oxaloacetate; gluconeogenesis E) glycogen; glycogenolysis Answer: B Difficulty: Easy Section Reference: 19-1 Learning Objective: Summarize the metabolic functions of liver, kidney, muscle, and adipose tissue

9) What type of receptor is the insulin receptor?

A) tyrosine kinase receptor B) G-protein coupled receptor C) serine/threonine phosphatase receptor D) nuclear receptor E) MAP kinase coupled receptor

Answer: A Difficulty: Easy Section Reference: 19-2 Learning Objective: Describe the effects of insulin, glucagon, and epinephrine on fuel metabolism 10) The  cells of the pancreatic islets secrete _____ in response to _____ glucose levels.

A) insulin; high B) insulin; low C) glucagon; high D) glucagon; low E) epinephrine; low Answer: D Difficulty: Medium Section Reference: 19-2 Learning Objective: Describe the effects of insulin, glucagon, and epinephrine on fuel metabolism 11) How does insulin cause an increase in the rate of glucose transport into cells?

A) binds to the glucose transporter causing a conformational change resulting in greater transport velocity B) activates Na/K ATPase to increase glucose active transport C) recruits glucose transporters from intracellular vesicles to the cell membrane D) activates an insulin-dependent porin that allows for rapid glucose transport E) all of the above Answer: C Difficulty: Medium Section Reference: 19-2 Learning Objective: Describe the effects of insulin, glucagon, and epinephrine on fuel metabolism

12) Which of the following enzymes is inhibited as a result of glucose binding to its receptor?

A) glycogen synthase B) pyruvate kinase C) acetyl-CoA carboxylase D) pyruvate dehydrogenase E) fructose-1,6-bisphosphatase

Answer: E Difficulty: Medium Section Reference: 19-2 Learning Objective: Describe the effects of insulin, glucagon, and epinephrine on fuel metabolism

13) Which of the following is an activator of glycogen synthase?

A) AMP B) UDP-glucose C) cAMP-dependent protein kinase D) glucose-6-phosphate E) all of the above Answer: D Difficulty: Medium Section Reference: 19-2 Learning Objective: Describe the effects of insulin, glucagon, and epinephrine on fuel metabolism

14) Glycogen phosphorylase has its greatest activity when _____; glycogen synthase has its greatest activity when _____.

A) phosphorylated; not phosphorylated B) phosphorylated; phosphorylated C) not phosphorylated; phosphorylated D) not phosphorylated; not phosphorylated E) neither enzyme is controlled by phosphorylation Answer: A Difficulty: Medium Section Reference: 19-2 Learning Objective: Describe the effects of insulin, glucagon, and epinephrine on fuel metabolism

15) The effect of epinephrine upon the liver is most similar to which of the following hormones?

A) insulin B) glucagon C) leptin D) resistin E) ghrelin

Answer: B Difficulty: Easy Section Reference: 19-2 Learning Objective: Describe the effects of insulin, glucagon, and epinephrine on fuel metabolism 16) Which of the following best explains the chain of events that occurs when glucagon binds to its receptor?

A) activation of protein kinase A, activation of G protein, activation of adenylate cyclase, production of cAMP B) activation of adenylate cyclase, production of cAMP, activation of protein kinase A, activation of G protein C) production of cAMP, activation of adenylate cyclase, activation of protein kinase A, activation of G protein D) activation of G protein, activation of protein kinase A, activation of adenylate cyclase, production of cAMP E) activation of G protein, activation of adenylate cyclase, production of cAMP, activation of protein kinase A Answer: E Difficulty: Hard Section Reference: 19-2 Learning Objective: Describe the effects of insulin, glucagon, and epinephrine on fuel metabolism

17) Which of the following is a second messenger?

A) cortisol B) epinephrine C) ghrelin D) cyclic AMP E) none of the above Answer: D Difficulty: Easy Section Reference: 19-2 Learning Objective: Describe the effects of insulin, glucagon, and epinephrine on fuel metabolism 18) What hormone that is produced in adipose tissue signals satiety?

A) adiponectin B) cholecystokinin C) leptin D) ghrelin E) amylin Answer: C Difficulty: Easy Section Reference: 19-2 Learning Objective: Describe the effects of insulin, glucagon, and epinephrine on fuel metabolism

19) Where are the receptors for leptin and PYY3-36 located?

A) hypothalamus B) pancreas C) liver D) adipose tissue E) intestine Answer: A Difficulty: Medium Section Reference: 19-2 Learning Objective: Describe the effects of insulin, glucagon, and epinephrine on fuel metabolism 20) In the liver, activation of AMP-dependent protein kinase occurs when levels of _____ are elevated, resulting in the activation of _____.

A) AMP; acetyl-CoA carboxylase B) ADP; phosphofructokinase-2 C) ATP; glycogen phosphorylase D) AMP; fructose-1,6-bisphosphatase E) ADP; lactate dehydrogenase Answer: B Difficulty: Hard Section Reference: 19-2 Learning Objective: Describe the effects of insulin, glucagon, and epinephrine on fuel metabolism 21) After several days of fasting, the liver begins producing relatively large amounts of ketone bodies. Which type of tissue is highly dependent upon this as its sole source of energy in the

absence of glucose?

A) heart B) kidney C) skeletal muscle D) brain E) all of the above Answer: D Difficulty: Medium Section Reference: 19-3 Learning Objective: Compare the metabolic changes that occur in starvation, obesity, and diabetes

22) During a long-term fast, which of the following is a major source of carbon for gluconeogenesis?

A) lactate B) acetoacetate C) 3-hydroxybutyrate D) acetone E) glycerol Answer: E Difficulty: Easy Section Reference: 19-3 Learning Objective: Compare the metabolic changes that occur in starvation, obesity, and diabetes

23) What hormone is most likely responsible for the body weight set-point?

A) adiponectin B) cholecystokinin C) leptin D) ghrelin E) all of the above Answer: C Difficulty: Easy Section Reference: 19-3 Learning Objective: Compare the metabolic changes that occur in starvation, obesity, and diabetes

24) What organelle is found in much higher amounts in brown adipose tissue than white adipose tissue?

A) mitochondria B) lysosome C) endoplasmic reticulum D) chloroplast E) none of the above Answer: A Difficulty: Easy Section Reference: 19-3 Learning Objective: Compare the metabolic changes that occur in starvation, obesity, and diabetes

25) Which of the following aspects of brown adipose tissue is responsible for its ability to generate heat?

A) brown adipose tissue contains many small fat droplets instead of one large globule B) blood flow to brown adipose tissue is larger than to white adipose tissue C) brown adipose tissue has receptors for norepinephrine D) the uncoupling protein allows fatty acid oxidation without ATP production E) none of the above Answer: D Difficulty: Medium Section Reference: 19-3 Learning Objective: Compare the metabolic changes that occur in starvation, obesity, and diabetes

26) Which of the following is the most common type of diabetes in the US? A) type 1 B) type 2 resulting from a genetic defect in the insulin receptor C) type 2 without a genetic defect in the insulin receptor D) type 3 E) all of the above are about equal in prevalence Answer: C Difficulty: Medium Section Reference: 19-3 Learning Objective: Compare the metabolic changes that occur in starvation, obesity, and diabetes

27) In a diabetic liver, which of the following pathways would be constantly active?

A) glycogen synthesis B) gluconeogenesis C) fatty acid synthesis D) ketone body oxidation E) glycolysis Answer: B Difficulty: Medium Section Reference: 19-3 Learning Objective: Compare the metabolic changes that occur in starvation, obesity, and diabetes

28) What happens to excess glucose in the eye that causes diabetics to develop cataracts?

A) oxidized to glucuronic acid causing aggregation of lens proteins B) reduced to sorbitol causing aggregation of lens proteins C) non-enzymatic glycosylation of lens proteins D) oxidized and cyclized to a lactone causing modification of lens proteins E) none of the above Answer: B Difficulty: Hard Section Reference: 19-3 Learning Objective: Compare the metabolic changes that occur in starvation, obesity, and diabetes

29) The synthesis of what liver enzyme is inhibited by the drug metformin, an activator of AMPK? A) phosphofructokinase B) glycogen phosphorylase C) acetyl-CoA carboxylase D) pyruvate carboxylase E) glucose-6-phosphatase Answer: E Difficulty: Medium Section Reference: 19-3 Learning Objective: Compare the metabolic changes that occur in starvation, obesity, and diabetes

30) What hormone that is commonly produced in typical body fat has very little production in visceral fat (also known as abdominal fat)?

A) leptin B) resistin C) neuropeptide Y D) ghrelin E) cholecystokinin Answer: A Difficulty: Easy Section Reference: 19-3 Learning Objective: Compare the metabolic changes that occur in starvation, obesity, and diabetes 31) TNF prevents the proper activity of IRS-1 triggering resistance to what hormone?

A) norepinephrine B) glucagon C) leptin D) insulin E) all of the above Answer: D Difficulty: Medium Section Reference: 19-3 Learning Objective: Compare the metabolic changes that occur in starvation, obesity, and diabetes

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 20 Question type: Multiple Choice 1) Which of the following explains why circular DNA, such as the chromosomes of some viruses and bacteria, appears to be twisted?

A) hybridization B) supercoiling C) circular DNA is Z-form D) viral and bacterial DNA is always single stranded E) none of the above Answer: B Difficulty: Easy Section Reference: 20-1 Learning Objective: Describe how topoisomerases alter DNA supercoiling

2) What are the two components of supercoiling?

A) twist and writhe B) twist and anti-twist C) writhe and relaxation D) negative supercoiling and positive supercoiling E) single stranded and double stranded Answer: A Difficulty: Easy Section Reference: 20-1 Learning Objective: Describe how topoisomerases alter DNA supercoiling

3) Which of the following explains supercoiling in naturally occurring DNA? A) positively supercoiled, making the helix tighter B) positively supercoiled, making the helix looser C) negatively supercoiled, making the helix tighter D) negatively supercoiled, making the helix looser E) negatively supercoiled without changing the nature of the helix

Answer: D Difficulty: Medium Section Reference: 20-1 Learning Objective: Describe how topoisomerases alter DNA supercoiling

4) What effect does a topoisomerase have upon DNA? A) denatures DNA B) converts double stranded DNA to single stranded DNA C) changes the supercoiling of DNA D) changes B-form DNA to A-form E) none of the above Answer: C Difficulty: Easy Section Reference: 20-1 Learning Objective: Describe how topoisomerases alter DNA supercoiling

5) An antibiotic that interferes with bacterial topoisomerase activity is _____, which specifically inhibits _____.

A) ciprofloxacin; DNA gyrase B) doxorubicin; type IA topoisomerase C) novobiocin; ATPase D) camptothecin; type II topoisomerase E) none of the above Answer: A Difficulty: Medium Section Reference: 20-1 Learning Objective: Describe how topoisomerases alter DNA supercoiling

6) An E. coli has _____ replication fork(s) on its single chromosome; humans have _____ replication fork(s) on each chromosome. A) 1; 1 B) 1; 2 C) 2; 2 D) 2; many

E) many; many Answer: D Difficulty: Easy Section Reference: 20-2 Learning Objective: Summarize the actions of the enzymes and other proteins involved in synthesizing the leading and lagging strands 7) What is the purpose of DNA helicase?

A) removal of negative supercoiling to allow for replication B) removal of positive supercoiling to allow for replication C) separation of double stranded DNA into single stranded DNA in front of DNA polymerase D) conversion of single stranded DNA to double stranded DNA behind DNA polymerase E) none of the above Answer: C Difficulty: Medium Section Reference: 20-2 Learning Objective: Summarize the actions of the enzymes and other proteins involved in synthesizing the leading and lagging strands 8) Besides the obvious role of keeping DNA in a single strand state, what do single-strand binding proteins do?

A) prevent supercoiling B) protect single stand DNA from nucleases C) aid in the formation of hairpin structures D) aid DNA polymerase with DNA binding E) all of the above Answer: B Difficulty: Medium Section Reference: 20-2 Learning Objective: Summarize the actions of the enzymes and other proteins involved in synthesizing the leading and lagging strands 9) Which of the following is correctly paired with its function?

A) helicase: creates single strand DNA

B) primase: production of an RNA primer for DNA polymerase C) RNase H: removal of RNA primer D) DNA ligase: joins the discontinuous segments on the lagging strand E) all of the above Answer: E Difficulty: Medium Section Reference: 20-2 Learning Objective: Summarize the actions of the enzymes and other proteins involved in synthesizing the leading and lagging strands

10) Which strand of DNA is replicated exclusively in a discontinuous fashion?

A) forward strand B) reverse strand C) leading strand D) lagging strand E) the strand that is read in a 5 to 3 direction Answer: D Difficulty: Easy Section Reference: 20-2 Learning Objective: Summarize the actions of the enzymes and other proteins involved in synthesizing the leading and lagging strands 11) What is the nucleophile in the DNA polymerase mechanism?

A) an oxygen anion on the -phosphate of the dNTP B) the oxygen on the -phosphate of the dNTP C) the oxygen on the -phosphate of the dNTP D) the 5 hydroxyl on the deoxyribose E) the 3 hydroxyl on the deoxyribose Answer: E Difficulty: Medium Section Reference: 20-2 Learning Objective: Summarize the actions of the enzymes and other proteins involved in synthesizing the leading and lagging strands 12) If the smallest human chromosome is 4.6107 base pairs in size, which of the following is

the best estimate of the number of Okazaki fragments resulting from its replication?

A) 300,000 B) 30,000 C) 3,000 D) 300 E) 30 Answer: A Difficulty: Hard Section Reference: 20-2 Learning Objective: Summarize the actions of the enzymes and other proteins involved in synthesizing the leading and lagging strands

13) What metal cations are found in the active site of DNA polymerase?

A) two Zn2+ B) one Zn2+ and one Mg2+ C) two Mg2+ D) one Mg2+ and one Ca2+ E) two Ca2+ Answer: C Difficulty: Easy Section Reference: 20-2 Learning Objective: Summarize the actions of the enzymes and other proteins involved in synthesizing the leading and lagging strands

14) Which of the following best describes a new strand of DNA relative to the template strand used to synthesize it?

A) an exact duplicate of the template B) a negative copy of the template C) a palindromic copy of the template D) an exact copy of the template but with the 3' and 5' ends reversed E) none of the above Answer: B Difficulty: Medium Section Reference: 20-2

Learning Objective: Summarize the actions of the enzymes and other proteins involved in synthesizing the leading and lagging strands 15) In most organisms, replication proceeds in a _____ manner from the _____.

A) bidirectional; replication origin B) bidirectional; theta site C) bidirectional; lagging strand D) unidirectional; chromosome ends E) none of the above Answer: A Difficulty: Easy Section Reference: 20-2 Learning Objective: Summarize the actions of the enzymes and other proteins involved in synthesizing the leading and lagging strands 16) Without telomeres, what would happen to the ends of eukaryotic chromosomes during replication?

A) they would be replicated just like the rest of the chromosome B) they would be mutated C) they would be lengthened D) they would be shortened E) none of the above Answer: D Difficulty: Easy Section Reference: 20-3 Learning Objective: Explain the synthesis and purpose of telomeres

17) Synthesis of telomeres requires the enzyme _____, which is a type of _____.

A) telomerase; helicase B) telomerase; reverse transcriptase C) ribonuclease; RNA-specific nuclease D) ribotelomerase; ligase E) none of the above Answer: B

Difficulty: Medium Section Reference: 20-3 Learning Objective: Explain the synthesis and purpose of telomeres 18) Which of the following is found in high concentration in all telomeres?

A) A B) C C) G D) T E) pyrimidines Answer: C Difficulty: Easy Section Reference: 20-3 Learning Objective: Explain the synthesis and purpose of telomeres 19) What does a reverse transcriptase do?

A) replicates DNA in a 3 to 5 fashion B) replicates RNA in a 5 to 3 fashion C) replicates RNA in a 3 to 5 fashion D) converts a DNA genome into an RNA genome E) converts an RNA genome into a DNA genome Answer: E Difficulty: Medium Section Reference: 20-3 Learning Objective: Explain the synthesis and purpose of telomeres 20) Which tumor suppressor gene is found to be mutated in at least half of all human tumors?

A) BRCA1 B) BRCA2 C) retinoblastoma D) p53 E) none of the above Answer: D Difficulty: Easy

Section Reference: 20-4 Learning Objective: Describe the enzymes and other proteins that repair damaged DNA 21) Which of the following is a potential modification to DNA that can result in a mutation or interfere with replication or trascription?

A) deamination of cytosine to uracil B) oxidation of guanine to 8-oxoguanine C) formation of thymine dimers by reaction with UV light D) reaction with hydroxyl radicals causing DNA strand breaks E) all of the above Answer: E Difficulty: Easy Section Reference: 20-4 Learning Objective: Describe the enzymes and other proteins that repair damaged DNA

22) Which of the following mutations would cause a bulge in the DNA backbone?

A) point mutation B) transversion mutation C) transition mutation D) frame shift mutation E) all of the above Answer: B Difficulty: Medium Section Reference: 20-4 Learning Objective: Describe the enzymes and other proteins that repair damaged DNA

23) Which type of DNA repair is used to remove and replace a single modified base that cannot be converted back to the normal base by a direct repair process?

A) base excision repair B) nucleotide excision repair C) mismatch repair D) DNA photolyase E) none of the above Answer: A

Difficulty: Medium Section Reference: 20-4 Learning Objective: Describe the enzymes and other proteins that repair damaged DNA 24) What is the process used for genes shuffling in meiosis that is also used to repair doublestrand breaks?

A) homologous end-joining B) nonhomologous end-joining C) recombination D) non-mutagenic strand coupling E) telomerase-assisted ligation Answer: C Difficulty: Medium Section Reference: 20-4 Learning Objective: Describe the enzymes and other proteins that repair damaged DNA

25) In the nucleus, DNA is wrapped around _____ to form _____.

A) ribosomes; heterochromatin B) histones; nucleosomes C) polyribose; euchromatin D) polyarginine; 30-nm fibers E) none of the above Answer: B Difficulty: Medium Section Reference: 20-5 Learning Objective: Describe how DNA is packaged in cells

26) Which of the nucleosome proteins is found in the linker DNA between nucleosomes and not actually part of the nucleosome core?

A) H1 B) H2A C) H2B D) H3 E) H4 Answer: A

Difficulty: Easy Section Reference: 20-5 Learning Objective: Describe how DNA is packaged in cells 27) Histone proteins that bind to areas of DNA that are highly transcribed are often _____ on _____ residues.

A) methylated; lysine B) phosphorylated; serine C) phosphorylated; tyrosine D) acetylated; histidine E) acetylated; lysine Answer: E Difficulty: Medium Section Reference: 20-5 Learning Objective: Describe how DNA is packaged in cells 28) Which of the following details the progression of structural levels from DNA to chromosome in eukaryotic DNA? A) A-DNA → 30-nm fiber → nucleosome → loop → chromosome B) A-DNA → nucleosome → loop → 30-nm fiber → chromosome C) B-DNA → nucleosome → 30-nm fiber → loop → chromosome D) B-DNA → nucleosome → loop → 30-nm fiber → chromosome E) Z-DNA → 30-nm fiber → nucleosome → loop → chromosome Answer: C Difficulty: Medium Section Reference: 20-5 Learning Objective: Describe how DNA is packaged in cells 29) What type of modification is used to make CpG islands?

A) acetylation of guanine B) methylation of guanine C) phosphorylation of guanine D) acetylation of cytosine E) methylation of cytosine

Answer: E Difficulty: Medium Section Reference: 20-5 Learning Objective: Describe how DNA is packaged in cells

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 21 Question type: Multiple Choice 1) Which of the following is responsible for RNA splicing?

A) rRNA B) miRNA C) tRNA D) siRNA E) snRNA Answer: E Difficulty: Easy Section Reference: 21-intro

2) Genomic DNA that encodes proteins undergoes the process of _____ to produce _____.

A) transcription; mRNA B) transcription; tRNA C) translation; rRNA D) translation; proteins E) transcription; proteins Answer: A Difficulty: Medium Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription

3) Which of the following best describes the nucleic acid complex formed during RNA polymerization?

A) two DNA-RNA hybrids since both DNA strands are transcribed simultaneously B) one DNA-RNA hybrid and one single stranded DNA C) one DNA-RNA hybrid with the other DNA strand bound to an RNA molecule on RNA polymerase D) there is no interaction between the growing RNA and the DNA

E) none of the above Answer: B Difficulty: Medium Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription

4) Addition of a(n) _____ group to certain lysine residues of a histone protein makes the region of chromatin transcriptionally _____; addition of a(n) _____ group to certain lysine residues makes the region of chromatin transcriptionally _____.

A) methyl; highly active; acetyl; active B) acetyl; silent; methyl; active C) phosphate; silent; methyl; silent D) methyl; silent; acetyl; active E) methyl; silent; phosphate; active Answer: D Difficulty: Hard Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription

5) What is the region immediately adjacent to the starting site for RNA polymerization called?

A) promoter B) enhancer C) initiator D) consensus sequence E) TF binding site Answer: A Difficulty: Easy Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription

6) Which subunit of the E. coli RNA polymerase recognizes the promoter region?

A)  B)  C)  D)  E)  Answer: E Difficulty: Easy Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription

7) Which of the eukaryotic transcription factors is responsible for binding the TATA box?

A) TFIIB B) TFIID C) TFIIE D) TFIIF E) TFIIH Answer: B Difficulty: Medium Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription 8) TFIIH is a transcription factor that is responsible for forming the transcription bubble. For this reason, TFIIH is best described as a _____.

A) gyrase B) ligase C) helicase D) endonuclease E) single-strand binding protein Answer: C Difficulty: Medium Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription

9) Eukaryotic enhancers are located up to _____ base pairs upstream from the promoter.

A) 50 B) 120 C) 500 D) 1,500 E) 120,000 Answer: E Difficulty: Easy Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription

10) The most prevalent mode of DNA-protein interaction is achieved with a(n) _____ that binds to the _____ groove of DNA. A) -helix; major B) -helix; minor C) -sheet; major D) -sheet; minor E) -turn; major Answer: A Difficulty: Medium Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription 11) Genes that are not often transcribed generally have _____ sequences that bind to _____ proteins.

A) inhibitor; mediator B) interrupter; regulatory C) obstruction; restraint D) silencer; repressor E) negative control; arrestor Answer: D Difficulty: Medium

Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription 12) The protein that is responsible for bringing together proteins bound to enhancers with proteins bound to promoters is called _____.

A) TAF1 B) chromatin remodeling enhancer C) mediator complex D)  subunit of RNA polymerase E) none of the above Answer: C Difficulty: Easy Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription

13) What sugar is metabolized by the enzymes under the control of the lac operon?

A) sucrose B) mannose C) galactose D) lactose E) maltose Answer: D Difficulty: Easy Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription 14) What does allolactose bind?

A) lac operon B) lac repressor C) operator D) promoter E) all of the above

Answer: B Difficulty: Medium Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription

15) Which of the following best describes the functioning of the lac repressor protein? A) in the presence of allolactose, the protein binds the operator inhibiting transcription B) in the presence of allolactose, the protein binds the operator enhancing transcription C) in the absence of allolactose, the protein binds the operator inhibiting transcription D) in the absence of allolactose, the protein binds the operator enhancing transcription E) none of the above Answer: C Difficulty: Medium Section Reference: 21-1 Learning Objective: Describe the roles of DNA sequences and transcription factors in initiating transcription

16) Which of the following eukaryotic RNA polymerase is correctly paired with the type of RNA that it produces?

A) RNA polymerase III: tRNA B) RNA polymerase I: rRNA C) RNA polymerase II: mRNA from protein-coding genes D) RNA polymerase III: small RNAs such as miRNA and snRNA E) all of the above Answer: E Difficulty: Medium Section Reference: 21-2 Learning Objective: Summarize the activity of RNA polymerase in elongation and termination

17) Separation of DNA into a single stranded region around RNA polymerase creates _____.

A) hybridized DNA B) a transcription bubble C) Z-DNA D) DNA bound to single stranded binding proteins

E) none of the above Answer: B Difficulty: Easy Section Reference: 21-2 Learning Objective: Summarize the activity of RNA polymerase in elongation and termination

18) How do the NTPs enter RNA polymerase? A) base-paired with the incoming (downstream) DNA B) with the incoming DNA but not base-paired with it C) from the exit site, as the DNA leaves the enzymes, the NTPs move in the opposite direction D) through a special channel sized just for NTPs E) there is no specific way, any of the above routes are used Answer: D Difficulty: Medium Section Reference: 21-2 Learning Objective: Summarize the activity of RNA polymerase in elongation and termination

19) What are the two metal ions found in the active site of RNA polymerase?

A) two Ca2+ B) a Ca2+ and a Zn2+ C) two Zn2+ D) a Zn2+ and a Mg2+ E) two Mg2+ Answer: E Difficulty: Easy Section Reference: 21-2 Learning Objective: Summarize the activity of RNA polymerase in elongation and termination

20) What is the approximate size of the DNA-RNA hybrid present inside the RNA polymerase?

A) 3 base pairs B) 6 base pairs C) 9 base pairs D) 12 base pairs E) 15 base pairs

Answer: C Difficulty: Easy Section Reference: 21-2 Learning Objective: Summarize the activity of RNA polymerase in elongation and termination

21) RNA polymerase is said to have high _____, meaning that it can catalyze thousands to millions of reactions without releasing the DNA template A) processivity B) continuity C) fidelity D) stability E) connectivity Answer: A Difficulty: Easy Section Reference: 21-2 Learning Objective: Summarize the activity of RNA polymerase in elongation and termination

22) Which transcription factor is required to aid RNA polymerase in the removal of an incorrect nucleotide incorporated into the growing RNA? A) TFIIP B) TFIIS C) TFIIT D) TFIIX E) TFIIZ Answer: B Difficulty: Medium Section Reference: 21-2 Learning Objective: Summarize the activity of RNA polymerase in elongation and termination

23) In prokaryotic transcription, what must be released for the switch from initiation to elongation to occur?

A) TFIIB B) ADP following phosphorylation of the RNA polymerase C-terminal domain C) regulatory subunit bound to the C-terminal domain

D)  subunit E) the TATA-binding protein Answer: D Difficulty: Medium Section Reference: 21-2 Learning Objective: Summarize the activity of RNA polymerase in elongation and termination

24) Phosphorylation of the C-terminal domain of eukaryotic RNA polymerase inhibits interaction with what protein, thus allowing the polymerase to leave the promoter?

A) mediator complex B) all transcription factors C) TFIIF and TFIIH D) TFIIS E) none of the above Answer: A Difficulty: Medium Section Reference: 21-2 Learning Objective: Summarize the activity of RNA polymerase in elongation and termination 25) What DNA sequence is found on the template strand at the termination of prokaryotic transcription?

A) series of CG repeats followed by string of 10-12 U B) section of Z-DNA followed by repetitive CAT sequence C) palindromic sequence followed by poly(A) region D) series of TATA boxes E) series of CpG islands Answer: C Difficulty: Medium Section Reference: 21-2 Learning Objective: Summarize the activity of RNA polymerase in elongation and termination 26) During termination, Rho acts as a _____.

A) polymerase B) ligase

C) NTP hydrolase D) single-strand binding protein E) helicase Answer: E Difficulty: Medium Section Reference: 21-2 Learning Objective: Summarize the activity of RNA polymerase in elongation and termination

27) Eukaryotic transcription termination generally occurs at _____ sites in the DNA sequence.

A) stop B) pause C) disconnect D) exonuclease binding E) CpG island Answer: B Difficulty: Easy Section Reference: 21-2 Learning Objective: Summarize the activity of RNA polymerase in elongation and termination 28) Which of the following modifications occurs to all eukaryotic mRNA? A) addition of a poly(A) tail to the 3 end of the molecule B) hydrolysis of the terminal phosphate from the 5 triphosphate end of the molecule C) addition of GMP to the 5 end via a 5 to 5 linkage D) methylation of the 2 hydroxyl on the first nucleotide of the molecule E) all of the above Answer: E Difficulty: Medium Section Reference: 21-3 Learning Objective: Describe the ways that RNA is processed 29) What is the purpose of the poly(A) tail on eukaryotic mRNA? A) binds to short poly(U) molecules forming duplex RNA that resists degradation B) forms a stem loop to aid in transport to the cytosol C) aids in transport to the lysosome for degradation once the ribosome is finished with it

D) binds to the poly(A) binding protein to prevent exonuclease activity E) none of the above Answer: D Difficulty: Medium Section Reference: 21-3 Learning Objective: Describe the ways that RNA is processed

30) During mRNA synthesis, _____ are removed and the _____ are spliced together to create the mature mRNA A) introns; exons B) exons; introns C) snRNAs; miRNAs D) miRNAs; snRNAs E) none of the above Answer: A Difficulty: Easy Section Reference: 21-3 Learning Objective: Describe the ways that RNA is processed 31) What protein/RNA complex is responsible for the removal of introns?

A) intronase B) RNA processing complex C) spliceosome D) ribozyme E) none of the above Answer: C Difficulty: Easy Section Reference: 21-3 Learning Objective: Describe the ways that RNA is processed 32) In a typical gene, what percentage of the bases represents introns?

A) 5% B) 10% C) 25%

D) 50% E) 90% Answer: E Difficulty: Easy Section Reference: 21-3 Learning Objective: Describe the ways that RNA is processed

33) Which of the following allows a gene to give more than one viable protein product?

A) exon suppression B) alternative splicing C) use of RNA interference D) frame shift mutations E) action of the decapping enzyme Answer: B Difficulty: Easy Section Reference: 21-3 Learning Objective: Describe the ways that RNA is processed 34) Which of the following is the major factor in determining how quickly an mRNA is degraded?

A) overall length of the mRNA B) degree of intron removal C) how quickly the cap is removed D) length of poly(A) tail E) all of the above play a role Answer: D Difficulty: Medium Section Reference: 21-3 Learning Objective: Describe the ways that RNA is processed 35) Which of the following details the correct sequence of events for RNA interference mediated by siRNA? A) degradation of passenger RNA strand, binding of mRNA, formation of double-stranded RNA, cleavage by dicer, binding to RISC, cleavage of mRNA

B) binding to RISC, binding of mRNA, formation of double-stranded RNA, degradation of passenger RNA strand, cleavage by dicer, cleavage of mRNA C) formation of double-stranded RNA, cleavage by dicer, binding to RISC, degradation of passenger RNA strand, binding of mRNA, cleavage of mRNA D) binding of mRNA, formation of double-stranded RNA, degradation of passenger RNA strand, cleavage by dicer, binding to RISC, cleavage of mRNA E) binding of mRNA, formation of double-stranded RNA, cleavage by dicer, degradation of passenger RNA strand, binding to RISC, cleavage of mRNA, Answer: C Difficulty: Hard Section Reference: 21-3 Learning Objective: Describe the ways that RNA is processed

36) Which of the following is a common modification seen in rRNA and tRNA? A) dihydrouridine B) N2,N2-dimethylguanosine C) 3-methylcytidine D) pseudouridine E) all of the above Answer: E Difficulty: Medium Section Reference: 21-3 Learning Objective: Describe the ways that RNA is processed

37) Which of the following is seen in the following figure?

A) a standard G-C base pair with a nonstandard A-G base pair B) a standard A-U base pair with a nonstandard A-G base pair C) a standard G-U base pair with a nonstandard A-C base pair D) a standard A-C base pair with a nonstandard U-G base pair E) a standard G-U base pair with a nonstandard G-G base pair Answer: A Difficulty: Hard Section Reference: 21-3 Learning Objective: Describe the ways that RNA is processed

38) What modified base is seen in the following figure?

A) 3-methyluridine B) 3-methylcytidine C) 3-methyladenosine D) 3-methylguanosine E) none of the above Answer: B Difficulty: Hard Section Reference: 21-3 Learning Objective: Describe the ways that RNA is processed 39) Which of the following best describe the following base pair?

A) a typical G-C base pair B) a typical A-U base pair C) a nonstandard C-A base pair D) a nonstandard G-U base pair E) a nonstandard G-C base pair Answer: D Difficulty: Hard Section Reference: 21-3 Learning Objective: Describe the ways that RNA is processed 40) Which of the following is thought to be the origin of RNA interference?

A) removal of mistranscribed mRNA B) removal of excessive mRNA C) antiviral defense D) antibiotic for RNA based bacteria E) none of the above Answer: C Difficulty: Easy Section Reference: 21-3 Learning Objective: Describe the ways that RNA is processed

Package Title: Pratt & Cornely Test Bank Course Title: Pratt & Cornely Chapter Number: 22 Question type: Multiple Choice 1) The genetic code is said to be _____ because several codons may correspond to the same amino acid.

A) deteriorate B) despicable C) degenerate D) decadent E) depraved Answer: C Difficulty: Easy Section Reference: 22-intro

2) What is the similarity between the amino acids that have only one codon each?

A) they are aromatic amino acids B) they are the sulfur containing amino acids C) they are neutral polar amino acids D) they occur very infrequently in proteins E) none of the above Answer: D Difficulty: Easy Section Reference: 22-intro

3) The codon is found _____ while the anticodon is found _____.

A) on the proteins of the ribosome; in the mRNA B) in the mRNA; on the RNA of the ribosome C) on the tRNA; on the RNA of the ribosome D) on the tRNA; in the mRNA E) in the mRNA; on the tRNA Answer: E

Difficulty: Easy Section Reference: 22-intro 4) Which of the following describes the general three-dimensional structure of a tRNA? A) a cloverleaf shape with the anticodon and acceptor stem on “leaves” that are opposite each other B) an L shape with the anticodon at one end of the L and the acceptor stem at the other C) a large loop with the anticodon and 3 end in very close proximity to each other D) an elongated cylinder shape with the anticodon and acceptor stem at opposite ends E) since all tRNAs have very different three-dimensional structure, it is difficult describe a general shape Answer: B Difficulty: Medium Section Reference: 22-1 Learning Objective: Describe tRNA structure and aminoacylation 5) Which of the following is the only tRNA loop that is exclusively single stranded RNA? A) acceptor step B) D loop C) TC loop D) anticodon loop E) none of the above Answer: E Difficulty: Medium Section Reference: 22-1 Learning Objective: Describe tRNA structure and aminoacylation 6) During the charging of a tRNA, what intermediate is formed?

A) aminoacyl-adenylate B) aminoacyl-tRNA C) aminoacyl-ADP D) tRNA-adenylate E) none of the above Answer: A

Difficulty: Medium Section Reference: 22-1 Learning Objective: Describe tRNA structure and aminoacylation 7) Which of the following explains why the aminoacyl-tRNA synthetase for isoleucine rarely incorporates valine despite the similar structure of these two amino acids?

A) valine does not fit into the binding site for isoleucine B) only leucine and isoleucine can fit in the active site of the enzyme C) the enzyme contains a proofreading site that only allows isoleucine D) the enzyme contains a proofreading site that only excludes isoleucine E) none of the above Answer: D Difficulty: Hard Section Reference: 22-1 Learning Objective: Describe tRNA structure and aminoacylation 8) Which of the following is required for the correct charging of a tRNA? A) tRNA, mRNA, amino acid, GTP and aminoacyl-tRNA synthetase B) tRNA, amino acid, ATP and aminoacyl-tRNA synthetase C) tRNA, amino acid, ATP and transpeptidase D) tRNA, amino acid, GTP and transpeptidase E) tRNA, mRNA, amino acid, ATP and transpeptidase Answer: B Difficulty: Easy Section Reference: 22-1 Learning Objective: Describe tRNA structure and aminoacylation 9) What type of bond connects the tRNA with its amino acid (AA)?

A) ester between AA carboxylate and tRNA 3 hydroxyl B) mixed anhydride of AA carboxylate and tRNA 3 phosphate C) phosphoramide of AA amine and tRNA 3 phosphate D) mixed anhydride of AA carboxylate and tRNA 5 phosphate E) phosphoramide of AA amine and tRNA 5 phosphate Answer: A

Difficulty: Hard Section Reference: 22-1 Learning Objective: Describe tRNA structure and aminoacylation 10) Where is the anticodon in the following structure?

A) 1 B) 2 C) 3 D) 4 E) 5 Answer: C Difficulty: Easy Section Reference: 22-1 Learning Objective: Describe tRNA structure and aminoacylation 11) Given the following anticodon, which mRNA codon would pair with it?

5-IGC-3 A) 5-UCA-3 B) 5-UCG-3 C) 5-ACU-3 D) 5-GUA-3 E) 5-GCU-3 Answer: E

Difficulty: Hard Section Reference: 22-1 Learning Objective: Describe tRNA structure and aminoacylation 12) Approximately what fraction of the mass of a ribosome is due to protein? A) 1/2 B) 1/3 C) 1/4 D) 1/5 E) 1/6 Answer: B Difficulty: Easy Section Reference: 22-2 Learning Objective: Recognize the major features of the ribosome

13) What are the predominant interactions between the 30S and 50S subunits that allow the formation of the 70S ribosome? A) 30S protein with 50S rRNA B) 30S rRNA with 50S protein C) protein-protein interactions from both subunits D) rRNA-rRNA interactions from both subunits E) interactions of 50S rRNA with tRNA D loop and interactions of 30S rRNA with anticodon loop are the only interactions holding the 70S ribosome together Answer: D Difficulty: Medium Section Reference: 22-2 Learning Objective: Recognize the major features of the ribosome

14) Why does the mRNA adopt a sharp bend as it moves through the ribosome?

A) so that the mRNA can enter the 30S subunit and exit the 50S subunit B) in order to maximize base pairing with the 23S rRNA C) so the tRNAs in both the A and P site can interact with their appropriate codons D) to prevent dissociation of the 30S and 50S subunits E) all of the above

Answer: C Difficulty: Hard Section Reference: 22-2 Learning Objective: Recognize the major features of the ribosome

15) Which of the following tRNA binding sites is correctly defined?

A) A site: accepts incoming aminoacyl-tRNA B) E site: entrance site for initial tRNA binding C) P site: site occupied by the tRNA that accepts the growing peptide chain D) T site: site that is briefly occupied while the tRNA is passed from the A site to P site E) all of the above Answer: A Difficulty: Easy Section Reference: 22-2 Learning Objective: Recognize the major features of the ribosome

16) Which amino acid is the first incorporated into a prokaryotic protein?

A) N-formylthreonine B) N-formylmethionine C) N-formylaspartate D) N-formylglutamine E) N-formylcysteine Answer: B Difficulty: Easy Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination

17) What sequence is located about 10 bases upstream of the initiation codon?

A) Watson-Crick sequence B) Meselson-Stahl sequence C) Hershey-Chase sequence D) Avery-MacLeod sequence E) Shine-Dalgarno sequence Answer: E

Difficulty: Easy Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination 18) What two elements of translation are paired by a Shine-Dalgarno sequence? A) initial tRNA with the initiation codon B) initial tRNA with the ribosomal A site C) mRNA with 23S rRNA of the ribosome D) mRNA with 16S rRNA of the ribosome E) mRNA with initial tRNA Answer: D Difficulty: Medium Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination

19) In E. coli translation, _____ aids with binding of the fMet-tRNA to the 30S subunit while _____ blocks the A site. A) IF-1; IF-2 B) IF-1; IF-3 C) IF-2; IF-1 D) IF-2; IF-3 E) IF3; IF-1 Answer: C Difficulty: Medium Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination

20) Which of the following initiation steps results in GTP hydrolysis?

A) binding of mRNA to the 30S subunit B) binding of the 50S subunit to the 30S subunit C) binding of the fMet-tRNA to the ribosome D) binding of IF-2 to the 30S subunit E) binding of IF-1 to the A site Answer: B

Difficulty: Hard Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination 21) How is the initiation codon found in eukaryotic translation?

A) a sequence similar to the Shine-Dalgarno sequence is located B) the 5 cap binds just beyond the P site of the ribosome C) the fMet-tRNA is able to locate the initiation codon before binding to the ribosome D) when the mRNA circularizes, the poly(A) tail enables location of the initiation codon E) the first AUG codon is found when the 40S subunit scans the mRNA from the 5 end Answer: E Difficulty: Medium Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination 22) Which of the following best describes the preparation of fMet-tRNA for translation in prokaryotes?

A) Met is first added to a tRNA specific for the start codon that differs from that designed to carry Met, then formylated B) Met is first formylated, then added to a tRNA specific for the start codon and differs from the tRNA designed to carry Met C) Met is first added to a "regular" tRNAMet, then formylated; the fact that it has the formyl group allows use in the initiation codon D) Met is first formylated, then added to a "regular" tRNAMet; the fact that it has the formyl group allows use in the initiation codon E) fMet isn't used in prokaryotes, only in eukaryotes Answer: A Difficulty: Hard Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination

23) Which of the following is true regarding the interaction of EF-Tu with aminoacyl-tRNAs? A) the higher the occurrence of an amino acid in a protein, the stronger the interaction B) EF-Tu binds charged and uncharged tRNAs with the same affinity C) free aminoacyl-tRNAs can only bind to the ribosome in vitro

D) binding occurs with about equal affinity for all aminoacyl-tRNAs E) the interaction always involves the anticodon loop Answer: D Difficulty: Hard Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination

24) The interaction used to insure correct codon-anticodon recognition involves RNA interactions from _____ that specifically check interactions at _____.

A) mRNA and tRNA; first and second codon positions B) mRNA and tRNA; second and third codon positions C) mRNA, tRNA and rRNA; first and second codon positions D) mRNA, tRNA and rRNA; second and third codon positions E) mRNA, tRNA and rRNA; all three codon positions Answer: C Difficulty: Hard Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination 25) Hydrolysis of GTP by EF-Tu is thermodynamically required for _____.

A) proofreading B) transpeptidation C) translocation D) aminoacyl-tRNA binding to the ribosomal A site E) none of the above Answer: A Difficulty: Medium Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination 26) Besides the proofreading function of EF-Tu, what other mechanism is used to insure the proper tRNA is in the A site?

A) interaction between the D loop and the 50S subunit B) interaction between the TC loop and the 30S subunit

C) interaction of the aminoacyl group with certain proteins in the A site D) interaction of the codon with the 50S subunit E) none of the above Answer: E Difficulty: Medium Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination

27) Polypeptide synthesis proceeds from the _____ to the _____.

A) entrance site; exit site B) 50S subunit; 30S subunit C) C-terminus; N-terminus D) N-terminus; C-terminus E) peptidyl site; aminoacyl site Answer: D Difficulty: Easy Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination 28) Which of the following provides the energy for the peptidyl transferase reaction?

A) GTP → GDP + Pi B) GTP → GMP + PPi C) ATP → ADP + Pi D) ATP → AMP + PPi E) since an ester is being converted to an amide, no external energy input is required Answer: E Difficulty: Medium Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination 29) Which of the following is responsible for the catalytic activity of peptidyl transferase?

A) protein component of 50S subunit B) rRNA component of 50S subunit C) protein component of 30S subunit

D) rRNA component of 30S subunit E) both protein and rRNA of the 50S subunit Answer: B Difficulty: Easy Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination

30) What type of catalysis is seen by the nucleotides in the active site of peptidyl transferase?

A) acid-base catalysis B) nucleophilic catalysis C) electrophilic catalysis D) proximity and orientation effects E) covalent catalysis Answer: D Difficulty: Hard Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination 31) EF-G is required for _____ as it binds to the ribosome in a manner similar to _____.

A) translocation; the EF-Tu-tRNA complex B) transpeptidation; the EF-Tu-GDP complex C) transferase; an uncharged tRNA D) transduction; an aminoacyl-tRNA E) none of the above Answer: A Difficulty: Hard Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination 32) Which of the following antibiotics mimics an aminoacyl-tRNA? A) chloramphenicol B) erythromycin C) penicillin D) puromycin

E) streptomycin Answer: D Difficulty: Medium Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination

33) What recognizes stop codons?

A) a termination tRNA that does not carry an amino acid on its acceptor stem B) release factors C) ribosome recycling factors D) fMet-tRNA E) nothing recognizes stop codons, that is why translation ceases Answer: B Difficulty: Easy Section Reference: 22-3 Learning Objective: Summarize the events of translation initiation, elongation, and termination

34) Which of the following aids in protein folding by completely sequestering a polypeptide from its environment?

A) ubiquitin B) trigger factor C) chaperonin D) heat shock protein E) signal recognition particle Answer: C Difficulty: Medium Section Reference: 22-4 Learning Objective: List the events that occur during post-translational processing

35) Chaperones such as trigger factor generally bind to what regions of a polypeptide?

A) hydrophobic regions B) acidic regions C) basic regions D) both acidic and basic regions

E) neutral polar regions Answer: A Difficulty: Easy Section Reference: 22-4 Learning Objective: List the events that occur during post-translational processing

36) Signal recognition particle is a _____ whose function is to _____.

A) DNA-protein complex; transport proteins into the eukaryotic nucleus B) ribonucleoprotein; direct proteins to the membrane or endoplasmic reticulum C) chaperone; aid in protein folding D) glycosylase; catalyze posttranslational modification E) none of the above Answer: B Difficulty: Medium Section Reference: 22-4 Learning Objective: List the events that occur during post-translational processing

37) In eukaryotic cells, when a protein is to be translocated to the endoplasmic reticulum, what must occur for complete translation to occur?

A) the N-terminus binds SRP which then docks with a receptor on the ER B) the N-terminus binds SRP which is then partially cleaved by a signal peptidase C) the ribosome must be translocated into the ER D) the ribosome must be bound to the ER before translation begins E) a chaperone protein embedded in the ER membrane binds the N-terminus Answer: A Difficulty: Medium Section Reference: 22-4 Learning Objective: List the events that occur during post-translational processing

38) Chaperonins such as the GroEL/ES system function _____.

A) only when heat shock proteins are activated B) in a non-aqueous environment C) only at low pH D) only when bound to the ER membrane

E) in an ATP-dependent manner Answer: E Difficulty: Medium Section Reference: 22-4 Learning Objective: List the events that occur during post-translational processing

39) Which of the following commonly occurs at asparagine residues of extracellular proteins?

A) hydrolysis of the amide to form Asp B) phosphorylation C) glycosylation D) peptide cleavage E) none of the above Answer: C Difficulty: Easy Section Reference: 22-4 Learning Objective: List the events that occur during post-translational processing

40) Which of the following occurs during the post-translational processing of insulin?

A) glycosylation B) phosphorylation C) acetylation of lysine residues D) formation of disulfide bonds E) amidation of the C-terminal amino acid Answer: D Difficulty: Medium Section Reference: 22-4 Learning Objective: List the events that occur during post-translational processing

41) Attachment of _____ to a Lys residue of a protein targets it for transport into the nucleus.

A) ubiquitin B) SUMO C) SRP D) DnaK E) trigger factor

Answer: B Difficulty: Medium Section Reference: 22-4 Learning Objective: List the events that occur during post-translational processing