Cell Structure and Types (4.9, 4.10, 4.11, and 4.12)

Question 1

Golgi apparatus

Answer 1

An organelle in eukaryotic cells consisting of stacks of membranous sacs that modify, store, and ship products of the endoplasmic reticulum.

Question 2

Note 1 —-»

Answer 2

The Golgi apparatus serves as a molecular warehouse and processing station for products manufactured by the ER. You can follow these activities. Note that, unlike the ER sacs, the flattened Golgi sacs are not connected.

1. One side of a Golgi stack serves as a receiving dock for transport vesicles produced by the ER.
2. A vesicle fuses with a Golgi sac, adding its membrane and contents to the “receiving” side. Products of the ER are modified as they progress through the stack.
3. The “shipping” side of the Golgi functions as a depot, dispatching its products in vesicles that bud off and travel to other sites.

Question 3

What is the relationship of the Golgi apparatus to the ER in a protein-secreting cell?

Answer 3

The Golgi receives transport vesicles budded from the ER that contain proteins synthesized by bound ribosomes. The Golgi finishes processing the proteins and dispatches transport vesicles to the plasma membrane, where the proteins are secreted.

Question 4

Lysosome

Answer 4

A digestive organelle in eukaryotic cells, that contains the hydrolytic enzymes, that digests engulfed food or damaged organelles.

Question 5

How is a lysosome like a recycling center?

Answer 5

It breaks down damaged organelles and recycles their molecules.

Question 6

Central Vacuole

Answer 6

A large membranous sac with diverse roles in growth and the storage of chemicals and wastes.

Question 7

Is a food vacuole part of the endomembrane system? Explain.

Answer 7

Yes, it forms by pinching in from the plasma membrane, which is part of the endomembrane system.

Question 8

Peroxisome

Answer 8

An organelle containing enzymes that transfer hydrogen atoms from various substrates to oxygen, producing and then degrading hydrogen peroxide.

Question 9

Note 2 —-»

Answer 9

In your liver, peroxisomes detoxify harmful compounds. In these processes, enzymes transfer hydrogen from the compounds to oxygen, producing hydrogen peroxide (H2O2). Other enzymes in the peroxisome convert this toxic by-product to water—another example of the importance of a cell’s compartmental structure.

Question 10

Note 3 —-»

Answer 10

A cell requires a continuous supply of energy to perform the work of life.

Question 11

How do transport vesicles help tie together the endomembrane system?

Answer 11

Transport vesicles move membranes and the substances they enclose between components of the endomembrane system.