The right answer is: voltage-gated channels
Ionic channels are membrane proteins that allow the selective passage of the cell membrane by ions (Na +, Ca2 +, K +, Cl-, ...) following the electrochemical gradients. They play a vital role in cellular excitability, triggering and propagation of action potential. They intervene in the coupling excitation-contraction and excitation-secretion. Ion channel selectivity is based on the adequacy of ion size and charges with the structure and amino acid sequence of the channels.
Among these channels, there are voltage-gated channels.
These are ion channels whose opening is activated by the membrane potential.
These dependent volumetric channels are characterized:
- by the selectivity of the ions (Ca2 +, Na +, K +, Cl-, ...)
- by their conductance
- by their activation domain (significant depolarization to low)
- by their kinetics of inactivation (slow, fast or transient)
