3 Describe the function of the voltagegate sodium ion channe

3. Describe the function of the voltage-gate sodium ion channel. In your description, explain what is meant by channel gating and channel inactivation.

Solution

In some cells like neurons, muscle cells (myocytes), and neuroendocrine system, Voltage-gated sodium channels plays an important role for the initiation of an action potential. Ligand-gated sodium channels are responsible for creating changes in the membrane potential. If enough Na+ channels are opened when there is a change in the cell\'s membrane potential, a small number of Na⁺ ions moves into the cell down their electrochemical gradient, thus depolarizing the cell. The more the Na+ channels, the greater will be the action potential inside the cell. The closing and opening of Na+ channels called as Channel Gating will be very fast when compared with K+ channels thus, creating the influx of more positive charges (Na+) which results the beginning of an action potential.

When action potential are at peaks, i.e when enough Na⁺ has entered the cell, the membrane\'s potential will be high and therefore the Na⁺ channels inactivate themselves by closing their inactivation gates. This closing of the inactivation gate causes Na⁺ ions flow through the channel to stop, which causes the membrane potential to stop increasing. Thus the channel is said to be inactivated and this process is called as Channel Inactivation.