Which one of the following is an example of simple diffusionSelect one:a. Sodium influx via voltage gated sodium channelb. Amino acid transport from intestinal lumen into the cellsc. Glucose transport from intestinal lumen into the cellsd. Glucose transport from intestinal cells to the blood

The correct answer is a. Sodium influx via voltage gated sodium channel.

Here's why:

Simple diffusion is a process by which small and nonpolar molecules, such as oxygen, carbon dioxide, and lipids, move across the cell membrane from an area of high concentration to an area of low concentration. This process does not require energy (ATP).

a. Sodium influx via voltage gated sodium channel: This is an example of facilitated diffusion, not simple diffusion. Facilitated diffusion involves the use of a protein to facilitate the movement of molecules across the membrane. In this case, the voltage gated sodium channel is the protein that facilitates the movement of sodium ions.

b. Amino acid transport from intestinal lumen into the cells: This is an example of active transport. Amino acids are large polar molecules that cannot cross the lipid bilayer of the cell membrane by simple diffusion. They require a carrier protein and energy to be transported into the cell.

c. Glucose transport from intestinal lumen into the cells: This is also an example of active transport. Glucose is a large polar molecule that cannot cross the lipid bilayer of the cell membrane by simple diffusion. It requires a carrier protein and energy to be transported into the cell.

d. Glucose transport from intestinal cells to the blood: This is also an example of active transport. Glucose is transported out of the cells and into the blood against its concentration gradient, which requires energy.