Question

The inactivation gate

A) quickly opens and closes after depolarization.
B) is coupled to the movement of the activation gate, but is much slower.
C) depends on a change of +100 mV from rest to be signaled to close.
D) depends on a loss of Na+ permeability to be triggered.
E) depends on a loss of K+ permeability to be triggered.

Answer 1

The inactivation gate in the voltage-gated Na+ channel closes after a specific period of time, which is on the order of a fraction of a millisecond.

Step-by-step explanation:

The inactivation gate in the voltage-gated Na+ channel closes after a specific period of time, which is on the order of a fraction of a millisecond. It is coupled to the movement of the activation gate but is much slower. When a cell is at rest, the activation gate is closed, and the inactivation gate is open. However, when the threshold is reached and the activation gate opens, the inactivation gate closes, halting the influx of Na+ ions into the cell.