Sodium-Potassium Ion Exchange Pump (Na⁺/K⁺ ATPase)

The sodium-potassium ion exchange pump is an essential active transport mechanism found in the plasma membrane of nearly all animal cells. It uses energy derived from ATP hydrolysis to move sodium (Na⁺) and potassium (K⁺) ions against their respective concentration gradients, maintaining crucial electrochemical gradients across the cell membrane. For each cycle, 3 sodium ions are transported out of the cell, and 2 potassium ions are transported into the cell. This process is powered by ATP, which binds to and is hydrolyzed by the pump’s ATPase activity. The movement of more positive charges out than in makes this pump electrogenic, contributing directly to a negative resting membrane potential inside cells. Without this pump’s activity, cells would lose their ability to maintain osmotic balance, electrical excitability would be lost, and many secondary transport systems would fail.

Other names

Sodium-potassium pump

Inhibition of Na+/K+ ATPase activity