AP BIOLOGY

Detailed explanation-1: -Ion channel proteins allow ions to diffuse across the membrane. A gated channel protein is a transport protein that opens a “gate, ” allowing a molecule to pass through the membrane.

Detailed explanation-2: -Ion channels mediate the flow of ions across the plasma membrane of cells. They are integral membrane proteins, typically a multimer of proteins, which, when arranged in the membrane, create a pore for the flow of ions.

Detailed explanation-3: -Based on the stimulus to which they respond, ion channels are divided into three superfamilies: voltage-gated, ligand-gated and mechano-sensitive ion channels.

Detailed explanation-4: -Active transport is a kind of cellular transport in which substances like amino acids, glucose and ions are transported across cell membranes to a region that already has a high concentration of such substances.

Detailed explanation-5: -Ion channels are protein molecules that span across the cell membrane allowing the passage of ions from one side of the membrane to the other. They have an aqueous pore, which becomes accessible to ions after a conformational change in the protein structure that causes the ion channel to open.