A Tour of the Cell

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14

Fig. 6-UN1

Cell Component

Structure

Function

Houses chromosomes, made of

chromatin (DNA, the genetic

material, and proteins); contains

nucleoli, where ribosomal

subunits are made. Pores

regulate entry and exit of

materials.

Nucleus

(ER)

Concept 6.3

The eukaryotic cell’s genetic

instructions are housed in

the nucleus and carried out

by the ribosomes

Ribosome

Concept 6.4

Endoplasmic reticulum

The endomembrane system

regulates protein traffic and

performs metabolic functions

in the cell

(Nuclear

envelope)

Concept 6.5

Mitochondria and chloro-

plasts change energy from

one form to another

Golgi apparatus

Lysosome

Vacuole

Mitochondrion

Chloroplast

Peroxisome

Two subunits made of ribo-

somal RNA and proteins; can be

free in cytosol or bound to ER

Extensive network of

membrane-bound tubules and

sacs; membrane separates

lumen from cytosol;

continuous with

the nuclear envelope.

Membranous sac of hydrolytic

enzymes (in animal cells)

Large membrane-bounded

vesicle in plants

Bounded by double

membrane;

inner membrane has

infoldings (cristae)

Typically two membranes

around fluid stroma, which

contains membranous thylakoids

stacked into grana (in plants)

Specialized metabolic

compartment bounded by a

single membrane

Protein synthesis

Smooth ER: synthesis of

lipids, metabolism of carbohy-

drates, Ca2+ storage, detoxifica-tion of drugs and poisons

Rough ER: Aids in synthesis of

secretory and other proteins from

bound ribosomes; adds

carbohydrates to glycoproteins;

produces new membrane

Modification of proteins, carbo-

hydrates on proteins, and phos-

pholipids; synthesis of many

polysaccharides; sorting of Golgi

products, which are then

released in vesicles.

Breakdown of ingested substances,

cell macromolecules, and damaged

organelles for recycling

Digestion, storage, waste

disposal, water balance, cell

growth, and protection

Cellular respiration

Photosynthesis

Contains enzymes that transfer

hydrogen to water, producing

hydrogen peroxide (H2O2) as a

by-product, which is converted

to water by other enzymes

in the peroxisome

Stacks of flattened

membranous

sacs; has polarity

(cis and trans

faces)

Surrounded by nuclear

envelope (double membrane)

perforated by nuclear pores.

The nuclear envelope is

continuous with the

endoplasmic reticulum (ER).

Slide 117

Fig. 6-UN1a

Cell Component

Structure

Function

Concept 6.3

The eukaryotic cell’s genetic

instructions are housed in

the nucleus and carried out

by the ribosomes

Nucleus

Surrounded by nuclear