With regard to the action potential,
A)the efflux of K+ causes repolarization.
B)movement from the resting membrane potential to threshold potential is due to the outward leak of K+.
C)the Na+/K+ pump is responsible for repolarization.
D)both depolarization and repolarization are due to an influx of Na+.

Question

Quizplus · Accepted Answer

The efflux of K+ from the cell causes repolarization of the membrane potential, as K+ ions leave the cell and restore the negative charge inside. Movement from resting membrane potential to threshold potential is due to the inward movement of Na+ ions, not outward leak of K+. The Na+/K+ pump is not responsible for repolarization. Depolarization is due to an influx of Na+ ions, but repolarization is caused by the efflux of K+.

With Regard to the Action Potential