ion channel
Membranes, or phospholipid bilayers, which are electrical insulators,
build a hydrophobic, low dielectric barrier to hydrophilic and charged
molecules. Ion channels are a sort of membrane protein complexes.
Their function is to facilitate the diffusion of ions across biological
membranes. Ion channels provide a high conducting, hydrophilic
pathway across the hydrophobic interior of the membrane. Ion channels
act as gateways which allow ions to travel through them to respond to
multiple signal events. And they are approved to regulate a wide variety
of processes important to ionic homeostasis.