Cell Structure and Function

BASIC CYTOLOGY: Cell Parts & Functions Robert Perry Malibu High

ANIMAL CELL

PLANT CELL

CELL ANATOMY & PHYSIOLOGY

PLASMA MEMBRANE

PLASMA MEMBRANE

Separates the internal environment from the outside environment and allows only certain molecules in and out.

CYTOPLASM Serves as a “jelly” including the organelles which are suspended and held together. (NOT THE NUCLEUS)

NUCLEUS CYTOSKELETON

NUCLEUS

Largest organelle in the cell and contains most of the cell’s genetic information.

Nuclear envelope Chromatin

Nucleolus

Mitochondria !!

Rough ER

www.denniskunkel.com

CHROMATIN

CHROMATIN

Between cell divisions, the DNA is more loosely coiled and forms long thin strands.

Before the cell divides, it coils up more tightly and forms chromosomes.

NUCLEOLUS

Mainly involved in the assembly of ribosomes.

NUCLEAR ENVELOPE

Double membrane that encloses the genetic material.

NUCLEAR PORES

Help to regulate the exchange of materials (such as RNA and proteins) between the nucleus and the cytoplasm.

CENTRIOLES

nucleus

CENTRIOLES

Very important in cellular division where they arrange the mitotic spindles.

Image: http://www.edu.ipa.go.jp/ chiyo/HuBEd/HTML1/en/3D/cell.html

Like Cilia and Flagella, Centrioles are also made of microtubules.

source: http://cellbio.utmb.edu/CELLBIO/cilia.htm

cilia

CILIA ONLY A FEW CELLS HAVE CILIA !

Numerous short extensions of the cell membrane that contain microtubules and are used to propel fluids.

cilia

Ciliated marine protist

Ciliated epithelium in human trachea

Cilia are used to move fluids.

Protists use them to swim or to create feeding currents.

Multicelled animals use them to move the mucous out of the nasal passages.

FLAGELLUM kinetosome

FLAGELLUM

A long, thin structure that sticks out from the cell membrane helps single-cells move or swim.

Illustration Š Lizzie Harper

Euglena

FLAGELLA

Noctiluca

What is a flagellum?

These are whip-like structures that act like a propeller.

Some groups have one, others have two. Shown here is a photosynthetic flagellate protozoan: Euglena, and a common marine dinoflagellate, Noctiluca.

CYTOSKELETON microfilaments

microtubules

CYTOSKELETON

Protein fibers that maintain cell shape, holds organelles in place, and for some cells, it enables cell movement.

CYTOSKELETON

microtubules

microfilaments

(nucleus)

INTERMEDIATE FILAMENTS

Organize the inside structure of the cell by holding organelles and providing strength.

MICROFILAMENTS (Actin Filaments)

Mostly concentrated just beneath the cell membrane where they support the cell and help keep the cell’s shape.

MICROTUBULES

Hollow cylinders that hold organelles in place and allow them to move around the cell, and they form the mitotic spindle during cell division... also make up parts of cilia and flagella.

VESICLE

VESICLE

Used for organizing metabolism, transport, and storage of molecules...also used as chemical reaction chambers.

PEROXISOME

Vesicles that use oxygen to break down toxic substances in the cell.

ER

L

G

ER

the GERL

N

L

ER

G Exosome

ROUGH ENDOPLASMIC RETICULUM

A network of membranes that form hollow tubes, flattened sheets, and round sacs studded with ribosomes.

It assembles and transports proteins.

two ribosomal subunits: large subunit small subunit

RIBOSOMES FREE RIBOSOMES: make proteins used inside the cell.

RIBOSOMES ON THE RER: make proteins sent outside the cell

Decode genetic messages within mRNA, turning them into amino acid chains (proteins).

(hormones, digestive enzymes, antibodies)

PROTEINS ARE SYNTHESIZED

BY THE RIBOSOMES The subject of a separate lesson

N ER

SER

SMOOTH ENDOPLASMIC RETICULUM

A network of membranes that form hollow tubes, flattened sheets, and round sacs without attached ribosomes; used for lipid synthesis, calcium ion storage, and drug detoxification.

RER

G

TRANSPORT VESICLES

Move proteins from the rough endoplasmic reticulum to the Golgi apparatus.

GOLGI “packaging and shipping�

Modifies proteins from the RER.... also involved in the transport of lipids around.

L

G

LYSOSOMES Vesicles with enzymes

Break down harmful cell products and waste materials.

Golgi apparatus

flow

such as ENZYMES

The GERL N L G

ER

MITOCHONDRION

The MIGHTY MITOCHONDRION

MITOCHONDRION

Use energy from organic carbohydrates (food) to make ATP -- ATP is the cell’s energy source.

Mitochondria: RESPIRATION

C6H12O6 + O2 SUGAR (GLUCOSE)

OXYGEN GAS

------> CO2 + H2O CARBON DIOXIDE GAS

WATER VAPOR

+ 38 ATP (cellular energy)

INNER MEMBRANE MEMBRANE PROTEINS (ENZYMES) ATP

INNER MATRIX OUTER MEMBRANE CRISTAE

Mitochondrion !

mitoribosomes

MITOCHONDRIA reproduce by fission, just like bacteria. You get them from your mother’s ovum.

VACUOLE

VACUOLE

Membrane-bound organelles that can have secretory, excretory and storage functions.

CENTRAL VACUOLE

CENTRAL VACUOLE

Maintains turgor pressure against the cell wall to form a hydrostatic skeleton for terrestrial plant cells.

CENTRAL VACUOLE

NO WATER = NO TURGOR PLANT IS LIMP AND WILTED

WATER = TURGOR PLANT IS EXPANDED AND STANDS UP

CHLOROPLAST

The MIGHTY CHLOROPLAST

CHLOROPLAST

Capture light energy from the sun and use it with water and carbon dioxide to make carbohydrates (food) for the plant.

Chloroplast: PHOTOSYNTHESIS

CO2 + H2O

CARBON DIOXIDE GAS

LIQUID WATER

---solar energy---> C6H12O6 + O2 high energy

SUGAR (GLUCOSE)

OXYGEN GAS

CELL WALL

CELL WALL

Rigid layer that is found outside the cell membrane of plants, certain protists and bacteria....contains cellulose and protein...provides structural support and protection.

the end