Voltage-gated K⁺ channels: A) are closed during the falling phase of the action potential B) are slow to close C) are activated at threshold, but open a short time later D) both b and c E) all of the above

Question

Quizplus · Accepted Answer

Option A is incorrect because voltage-gated K+ channels open during the falling phase of the action potential, allowing K+ ions to flow out of the cell and repolarize the membrane. Option B is partially correct, as voltage-gated K+ channels do take some time to close after they open, contributing to the after-hyperpolarization phase of the action potential. Option C is also partially correct, as voltage-gated K+ channels are activated at the threshold potential but typically have a slight delay before fully opening. Therefore, the correct answer is D, as it combines the partially correct statements from options B and C.

Voltage-Gated K+ Channels

Voltage-Gated K⁺ Channels