Question

What happens to the resting membrane potential of -70 mV when channels for a cation with an equilibrium potential of -30 mV open ______.

A) membrane stabilization
B) repolarization
C) depolarization
D) returns to -70 mV
E) hyperpolarization

Answer 1

When channels for a cation with an equilibrium potential of -30 mV open, the resting membrane potential of -70 mV will undergo depolarization. During depolarization, the membrane potential moves towards zero, causing it to become less negative.

Step-by-step explanation:

When channels for a cation with an equilibrium potential of -30 mV open, the resting membrane potential of -70 mV will undergo depolarization. Depolarization is the process where the membrane potential moves towards zero, and in this case, the cation with an equilibrium potential of -30 mV will cause the membrane potential to become less negative.

During depolarization, the membrane potential moves away from the resting potential of -70 mV, but it does not return to that value. Instead, it reaches approximately +30 mV, leading to a brief phase of hyperpolarization due to delayed closing of potassium channels.