What is essential for maintaining the concentration differences of sodium and potassium ions in a cell?

The maintenance of concentration differences of sodium and potassium ions across the cell membrane is primarily achieved through the mechanism of active transport, specifically by the sodium-potassium pump (Na+/K+ ATPase). This pump actively moves sodium ions out of the cell and potassium ions into the cell, utilizing ATP to function against their concentration gradients.

While resting membrane potential is important for understanding how these ions affect the electrical state of the cell, it does not itself maintain the concentration gradients. Rather, it is a result of those gradients. The resting membrane potential reflects the uneven distribution of ions—created by active transport—across the cell membrane, ultimately influencing how the cell responds to stimuli.

Thus, active transport is the essential process responsible for keeping sodium and potassium concentrations at their necessary levels, supporting processes like nerve impulse transmission and muscle contraction, while resting membrane potential is a consequence of those established gradients.