Question

The type of movement of molecules that is specific and passive and which becomes saturated if all of the protein carriers are in use is:

a) Simple diffusion
b) Facilitated diffusion
c) Active transport
d) Osmosis

Answer 1

The type of movement of molecules that is specific and passive and becomes saturated if all of the protein carriers are in use is B. Facilitated diffusion.

Step-by-step explanation:

Facilitated diffusion is a process that allows the movement of substances across a membrane from an area of higher concentration to an area of lower concentration with the help of specific transmembrane proteins. These proteins act as channels or carriers to facilitate the passage of molecules or ions that cannot freely cross the membrane.

Unlike simple diffusion, facilitated diffusion is specific and passive. It is specific because each transport protein recognizes and binds to a particular solute, and it is passive because it does not require energy input from the cell or an energy source like ATP.

Facilitated diffusion can become saturated when all of the available protein carriers are occupied by solute molecules. At saturation, the rate of molecule movement reaches a maximum, and no more molecules can be transported until some of the carriers become available again. Therefore the correct answer is B. Facilitated diffusion.