Question

3.3 passive membrane transport is diffusion of molecules down their concentration gradient
a. there are three types of passive transport: _, _, and _.
b. _ is the movement of molecules down a concentration gradient, from areas of high concentration to areas of low concentration.

1. what is the difference between simple diffusion and facilitated diffusion?
2. _ is the diffusion of water through a selectively permeable membrane.

a. compared to cells, solutions may be _ (same solute concentration), resulting in no net movement of water between the solutions, _ (higher solute concentration), resulting in movement of water out of the cell, or _ (lower concentration), resulting in movement of water into the cell.

Explanation:

A. The three types of passive transport are simple diffusion, facilitated diffusion, and osmosis. Simple diffusion is the movement of small, non - polar molecules directly through the lipid bilayer of the membrane. Facilitated diffusion uses transport proteins (either channel proteins or carrier proteins) to move polar or large molecules down their concentration gradient. Osmosis is the diffusion of water across a selectively permeable membrane.

1. Simple diffusion does not require a transport protein and is mainly for small non - polar molecules like oxygen and carbon dioxide. Facilitated diffusion requires a transport protein (channel or carrier) and is for larger or polar molecules like glucose or ions.
2. Osmosis is the diffusion of water through a selectively permeable membrane. Isotonic solutions have the same solute concentration as the cell, hypertonic solutions have a higher solute concentration, and hypotonic solutions have a lower solute concentration.

Answer:

A. Simple diffusion, Facilitated diffusion, Osmosis
B. Diffusion

1. Simple diffusion doesn't need transport proteins, facilitated diffusion does.
2. Osmosis

a. Isotonic, Hypertonic, Hypotonic