AP BIOLOGY

Detailed explanation-1: -The cell membrane, also called the plasma membrane, is found in all cells and separates the interior of the cell from the outside environment. The cell membrane consists of a lipid bilayer that is semipermeable. The cell membrane regulates the transport of materials entering and exiting the cell.

Detailed explanation-2: -The plasma membrane or cell membrane is the flexible boundary of a cell that separates the cell from the rest of the world. It regulates what enters and leaves a cell and provides protection. This regulatory ability is called selective permeability.

Detailed explanation-3: -Plasma membrane controls the flow of substances in and out of cell.

Detailed explanation-4: -Channel proteins and carrier proteins help substances diffuse across a cell membrane. In this diagram, the channel and carrier proteins are helping substances move into the cell (from the extracellular space to the intracellular space). The channel protein has an opening that allows the substances to cross.