thermodynamics-student-notes1

AP BIOLOGY CELLULAR ENERGETICS

ENERGY EXCHANGES L AWS OF T HERMODYNAMICS First Law

PROBLEM

ANSWER

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Second Law

ENERGY E XCHANGES

EXERGONIC REACTIONS

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ENDERGONIC REACTIONS

COUPLED REACTIONS

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ATP

STRUCTURE

PRODUCTION

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HOW ATP DOES WORK TYPE OF WORK

COUPLED REACTION

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DESCRIPTION

QUESTIONS : 1.

Define each of the following terms: Term

Definition

Metabolism

Catabolism

Anabolism

2.

3.

Identify each of the following as true of Catabolism or Anabolism. ______ Release energy

______ “Downhill” reaction

______ Store/consume energy

______ “Uphill” reaction

______ Build complex molecules

______ Photosynthesis

______ Break down complex molecules

______ Cellular respiration

Define the following terms: Term Energy

Kinetic Energy

Potential Energy

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Definition

4.

5.

Identify each of the follo wing as having kinetic energy (KE) or potential energy (PE). ______ Child at top of slide

______ Water turning turbines

______ Child sliding down slide

______ Glucose

______ Water behind dam

______ Food molecules

According to the First Law of Thermodynamics, if the total energy before a reaction is 500 kcal, then the total energy after the reaction must be: ________________________________________________________________

6.

According to the Second Law of Thermodynamics, if the total energy before an energy exchange is 500 kcal, then the amount of useful energy after the exchange is: a. b. c.

7.

Less than 500 kcal 500 kcal More than 500 kcal

Does the Second Law of Thermodynamics contradict the First Law? Explain. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________

8.

Do highly ordered living organisms violate the Second Law of Thermodynamics?

Explain. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________

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In the equation ∆H = ∆G + T∆S, which part of the equation represents:

9.

10.

a.

Change in enthalpy?

_____________________________________

b.

Change in total energy?

_____________________________________

c.

Change in free energy?

_____________________________________

d.

Change in usable energy? _____________________________________

e.

Amount of energy available to do work? __________________________

f.

Change in entropy?

g.

Energy lost to the system? _____________________________________

_____________________________________

Complete the following chart: Graph A

Is ∆G positive or negative Exergonic or Endergonic Spontaneous Yes or No Uphill or Downhill Reaction Products have more or less energy than reactants

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Graph B

11.

Of the light energy reaching the earth from the sun, the earth’s plants are believed to convert less than 1% into the form of potential energy stored in the chemical bonds of food molecules. What happens to the rest of the energy? ________________________________________________________________ ________________________________________________________________

12.

Organisms cannot use heat energy to drive their energy-requiring processes.

Does this mean that the heat released by metabolism is of no use to them? Why or why not? ________________________________________________________________ ________________________________________________________________ ________________________________________________________________

13.

Shown below is an energy pyramid for an ecosystem. Use this pyramid to answer the questions that follow.

Top Carnivore

Carnivores

Herbivores

Producers

a.

What happens to the amount of available energy at each trophic level? ___________________________________________________________

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b.

Use the laws of thermodynamics to explain why this happens. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________

14.

What do the letters ATP represent? ________________________________________________________________

15.

What are the three main kinds of work performed by or in cells? ________________________________________________________________

16.

Identify the parts in the ATP molecule below.

17.

Diagram the chemical reactions that occur during the production and regeneration of ATP. Include the ∆G for the reactions.

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18.

Explain how ATP performs work. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________

19.

When ATP is produced, energy is required. What is the source of this energy? ________________________________________________________________

20.

When ATP is broken, energy is released. How is this energy used? ________________________________________________________________

21.

What is the ∆G of a system (reaction) that is in equilibrium? ________________________________________________________________ Can a system at equilibrium do work? ________________________________________________________________ Explain why or why not. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________

22.

How is equilibrium avoided in living systems? ________________________________________________________________ ________________________________________________________________ ________________________________________________________________

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