Question

The electrochemical equilibrium for potassium is achieved under which condition(s)?

A. The resting membrane potential
B. Depolarization leading to an action potential
C. Activity of the Na+/K+ ATPase
D. None of the above

Answer 1

Electrochemical equilibrium for potassium is reached at the resting membrane potential due to the net movement of K+ ions with the concentration gradient, regulated by the Na+/K+ ATPase and the cell's selective permeability to ions.

Step-by-step explanation:

The electrochemical equilibrium for potassium is achieved under the condition of the resting membrane potential. Potassium ions (K+) accumulate inside the neuron due to a net movement with the concentration gradient, facilitated by both the selective permeability of the cell membrane and action of Na+/K+ ATPase.

The Na+/K+ ATPase actively pumps K+ ions into the cell while expelling Na+ ions, consuming ATP in the process, and thus maintains the difference in ion concentration across the cell membrane. The cell possesses more potassium leakage channels than sodium leakage channels, allowing K+ to diffuse out of the cell more readily, which contributes to the negative charge inside the cell and sustains the resting membrane potential typically measured at around -70 mV.