AP BIOLOGY

Detailed explanation-1: -The simplest mechanism by which molecules can cross the plasma membrane is passive diffusion. During passive diffusion, a molecule simply dissolves in the phospholipid bilayer, diffuses across it, and then dissolves in the aqueous solution at the other side of the membrane.

Detailed explanation-2: -In simple diffusion, small noncharged molecules or lipid soluble molecules pass between the phospholipids to enter or leave the cell, moving from areas of high concentration to areas of low concentration (they move down their concentration gradient).

Detailed explanation-3: -Simple diffusion A process in which the substance moves through a semipermeable membrane or in a solution without any help from transport proteins. For example, bacteria deliver small nutrients, water and oxygen into the cytoplasm through simple diffusion.

Detailed explanation-4: -Hint: Simple diffusion can be described as a process in which the movement of substances occurs via a semipermeable membrane or in a solution without any help from transport proteins. The examples of simple diffusion can be bacteria delivering small nutrients, movement of water and oxygen into the cytoplasm.