Question

For a giant squid axon, when the membrane potential reach +40 mV, ______ will be triggered.

(1) voltage-gated K+ channels
(2) voltage-gated Na+ channels
(3) Na+/K+-ATPases
(4) K+ leak channels
(5) Na+ leak channels

Answer 1

When the membrane potential of a giant squid axon reaches +40mV, Na+/K+-ATPases will be triggered to restore the resting potential.

Step-by-step explanation:

The correct answer is (3) Na+/K+-ATPases.

When the membrane potential of a giant squid axon reaches +40mV, it triggers the activity of Na+/K+-ATPases. These enzymes actively transport sodium ions out of the cell and potassium ions into the cell, helping to restore the resting potential of the membrane after an action potential.

Both voltage-gated sodium ion channels and voltage-gated potassium ion channels play roles in the depolarization and repolarization of the membrane during an action potential, but the Na+/K+-ATPases are responsible for restoring the resting potential.