Question

During the repolarization phase of an Action Potential:

A. the K+ channels close

B. the inside of the cell becomes less negative

C. voltage-sensitive Na+ channels open

D. the membrane potential goes from -70 mV to +30 mV

E. K+ rush out of the cell

Answer 1

Question:

During the repolarization phase of an Action Potential:

A. the K+ channels close

B. the inside of the cell becomes less negative

C. voltage-sensitive Na+ channels open

D. the membrane potential goes from -70 mV to +30 mV

E. K+ rush out of the cell

Answer: E. K+ rush out of the cell

Explanation:

• The repolarization phase of the action potential involves closing of voltage-sensitive sodium channels and opening potassium channels.
• As the sodium ion entry declines, the slow voltage-gated potassium channels open and potassium(K+) ions rush out of the cell.
• The exit of potassium ion from the cell causes the cell to become more negative.
• Repolarization returns the membrane potential from +30mV to the -70 mV resting potential.

Thanks and please upvote.