The membrane is more permeable to K⁺ than to Na⁺ A) at resting potential B) during the rising phase of an action potential C) during the rising phase of a graded potential D) at resting potential and during the rising phase of an action potential E) at resting potential and during the rising phase of a graded potential

Question

Quizplus · Accepted Answer

At resting potential, the membrane potential is negative and it is more permeable to K+ ions due to the presence of leak channels. On the other hand, Na+ ions cannot cross the membrane easily as the membrane is less permeable to Na+ ions at resting potential. Therefore, the membrane is more permeable to K⁺ than to Na⁺ at resting potential. During the rising phase of an action potential and a graded potential, the membrane potential is depolarizing and the membrane becomes more permeable to Na+ ions, resulting in an influx of Na+ ions into the cell. However, this does not affect the fact that the membrane is less permeable to Na+ ions compared to K+ ions at resting potential.

The Membrane Is More Permeable to K+ Than to Na+

The Membrane Is More Permeable to K⁺ Than to Na⁺