Plasma membrane
Ex.
The plasma membrane (also called “cell membrane”) exhibits selective permeability between a cell and its watery environment.
The cell membrane is selective in allowing some substances to pass through while excluding or restricting others, a bit like a bouncer at a club who lets in only the pretty girls.
Mitochondria, chloroplasts, and lysosomes are organelles that have membranes, but these membranes do not form the surface of the cell, and each of these organelles has a specific function.
The endoplasmic reticulum is part of the endomembrane system of the cell and is located inside, not on the surface of, the cell.
All cells have voltages across their membranes. This voltage is called a(n) __________ and is often maintained by __________.
- iotonic solution; diffusion
- electrochemical gradient; diffusion
- None of the listed responses is correct.
- membrane potential; electrogenic pumps
- concentration gradient; osmosis
If a red blood cell and a plant cell were placed in seawater, what would happen to the two types of cells?
- The red blood cell would shrink, and the plant cell would gain water.
- Both cells would lose water; the red blood cell would shrivel, and the plant plasma membrane would pull away from the cell wall.
- Both cells would gain water by osmosis; the red blood cell would burst, and the plant cell would increase in turgor pressure.
- Seawater is isotonic to both cells, therefore, neither cell will change as there will be no movement of water into or out of the cells.
- The red blood cell would burst, and the plant cell would shrink.
