Question

If the ECF K+ concentration increases from 3 mM to 5 mM, what happens to the resting membrane potential of cells? Assume that the intracellular K+ concentration remains constant.

It hyperpolarizes.

It depolarizes.

It does not change.

Answer 1

The resting membrane potential of cells will hyperpolarize if the extracellular fluid (ECF) K+ concentration increases from 3 mM to 5 mM.

Step-by-step explanation:

The resting membrane potential of cells will hyperpolarize if the extracellular fluid (ECF) K+ concentration increases from 3 mM to 5 mM, assuming that the intracellular K+ concentration remains constant.

The resting membrane potential is maintained by the difference in the concentrations of ions inside and outside the cell. In the case of K+, the concentration gradient acts on it. As the extracellular K+ concentration increases, there will be an increased influx of K+ into the cell, which will cause the membrane potential to become more negative, resulting in hyperpolarization.

Therefore, the correct answer is that the resting membrane potential of cells hyperpolarizes when the ECF K+ concentration increases from 3 mM to 5 mM.