noun, plural: ion channels
A single protein or protein complex that traverses the lipid bilayer of cell membrane and form a channel to facilitate the movement of ions through the membrane according to their electrochemical gradient
Ion channels may be open or gated. The potassium leak channel is an example of open ion channel. Gated ion channels may be voltage-gated, ligand-gated, or mechanically-gated channels.
Ion channels are the common targets of pharmaceutical drugs, directly or indirectly, since they are capable of regulating the flow of ions to and from the cell. Many ions play in important physiological role in the normal metabolism of cells.