Question

In most animal cells, which ion can move through "leak" channels in the plasma membrane and, in so doing, establishes the resting membrane potential?

A. Cl-
B. K+
C. Na+
D. Ca2+

Answer 1

The potassium ion (K+) moves through leak channels in the plasma membrane to establish the resting membrane potential, commonly measured at -70 mV, with the Na+/K+ pump maintaining the ion gradients.

Step-by-step explanation:

In most animal cells, the ion that can move through "leak" channels in the plasma membrane and establishes the resting membrane potential is the potassium ion, represented as K+. These leak channels allow K+ to slowly move out of the cell, which contributes significantly to the negative charge inside the cell relative to the outside. The resting membrane potential is usually measured around -70 mV. While sodium ions (Na+) also have channels through which they can move, the plasma membrane in its resting state is more permeable to K+ than Na+. The Na+/K+ pump works actively to restore the concentration gradients of these ions after any movement, therefore playing a crucial role in maintaining the resting membrane potential and the overall function of the cell.