Biology Chapter 5: Section 5-2 Review: Active Transport

Explain how a phagocyte destroys bacteria.

If forms a pouch in its cell membrane and engulfs bacteria in the pouch. It forms a vesicle. It then fuses with lysosomes and the enzymes digest the bacteria.

The diagrams below represent the six steps in one cycle of the sodium-potassium pump.

*A.* 5 *B.* 4 *C.* 2 *D.* 1 *E.* 6 *F.* 3

The sodium-potassium pump transports...

*A.*...Na+ out of the cell and K+ into the cell.

Facilitated-diffusion carrier proteins and cell-membrane pumps both...

*B.*...are specific for the kinds of substances they transport.

Pinocytosis involves the transport of...

*B.*...fluids into the cell.

The energy needed to power the sodium-potassium pump is provided by the...

*C.*...splitting of ATP.

Exocytosis is a...

*D.*...way for cells to release large molecules, such as proteins.

*Endocytosis*

Endocytosis is the process by which cells ingest external fluid, macromolecules, and large particles.

On which side of the membrane are Na+ ions released from the pump?

External

Describe how a cell produces and releases proteins.

Proteins are made on ribosomes and packaged in vesicles by the Golgi apparatus. The vesicles move to the cell membrane and fuse with it, releasing the proteins from the cell through exocytosis.

*Vesicle*

A vesicle is a membrane-bound organelle that pinches off from the cell membrane during endocytosis or fuses with the cell membrane during exocytosis.

*Active Transport*

Active transport is the movement of materials across a membrane from an area of lower concentration to an area of higher concentration.

On which side of the membrane are K+ ions released from the pump?

Ctyosolic

*Phagocytosis*

Phagocytosis is a type of endocytosis in which cells ingest large particles or whole cells.

Why is it important that ions being transported across a cell membrane be shielded from the interior of the lipid bilayer?

The interior of the cell the lipid bilayer is nonpolar and repels ions which an attracted to polar environments.

Why is the sodium-potassium transport mechanism called a "pump"?

The mechanism uses energy to move, or pump, Na+ and K+ up their concentration gradient.