The repolarizing phase of the action potential
A)means that the inside of the cell is becoming more positive.
B)is caused by the movement of sodium (Na+) into the cell.
C)is caused by the movement of potassium (K+) out of the cell.
D)is caused by the Na+/K+ pump located in the membrane.

Question

Quizplus · Accepted Answer

During the repolarizing phase of the action potential, potassium ions (K+) move out of the cell, making the inside of the cell more negative again. This allows the cell to return to its resting state and be ready to fire another action potential if needed. Sodium (Na+) moves into the cell during the depolarizing phase, which causes the cell to become more positive. The Na+/K+ pump is involved in maintaining the concentration gradients of these ions but is not directly responsible for the repolarization of the cell during an action potential.

The Repolarizing Phase of the Action Potential