Question

during which specific phase of the action potential do voltage - gated potassium channels begin to close?
a.) continuous propagation
b.) repolarization
c.) hyperpolarization
d.) depolarization

Explanation:

During hyperpolarization, voltage - gated potassium channels begin to close. In the action potential process:

• Depolarization is when sodium channels open and sodium enters the cell.
• Repolarization is mainly due to potassium channels being open and potassium leaving the cell.
• Hyperpolarization occurs when the membrane potential becomes more negative than the resting potential. At this stage, the voltage - gated potassium channels (which were open during repolarization) start to close as the cell begins to return to the resting state.
• Continuous propagation is a mode of action potential spread, not a phase related to the closing of potassium channels in the context of the action potential phases (depolarization, repolarization, hyperpolarization).

Answer:

c. Hyperpolarization