Question

What is the role of K+-gated ion channels in an action potential?

A. They help reverse the action potential by repolarizing the cell.
B. They provide the energy for the sodium-potassium pump to reestablish resting potential.
C. They do not have a role in action potentials.
D. They lead to the action potential reaching its highest state of cell depolarization.

Answer 1

K+-gated ion channels play a crucial role in repolarizing the neuron during an action potential, which is the process that returns the cell to its resting state after depolarization.

Step-by-step explanation:

Role of K+-Gated Ion Channels in an Action Potential

The role of K+-gated ion channels in an action potential is to help reverse the action potential by repolarizing the cell. As sodium ions (Na+) flow into the neuron during the depolarization phase, the internal charge of the cell becomes more positive. Once the action potential peaks, K+-gated ion channels open, allowing potassium ions (K+) to exit the neuron. This flow of K+ out of the neuron brings the membrane potential back down, repolarizing the cell towards its resting state. During hyperpolarization, K+ channels may remain open a bit too long, resulting in an overshoot of the resting membrane potential. Eventually, the channels will close, and along with the Na+/K+ pump, the neuron will reach its resting potential again, ready for another action potential if needed.

Therefore, the correct answer to the question, 'What is the role of K+-gated ion channels in an action potential?' is A. They help reverse the action potential by repolarizing the cell.