In the primary active Na-K pump, how many sodium ions are exchanged for potassium ions?

In the primary active sodium-potassium pump, the mechanism functions to maintain the electrochemical gradient across the cell membrane. For every cycle of this pump, three sodium ions are transported out of the cell while two potassium ions are brought into the cell. This exchange is crucial for maintaining cellular functions, such as regulating membrane potential and controlling cell volume.

The energy utilized for this pump comes from ATP, which is hydrolyzed to provide the necessary energy for these ions to move against their concentration gradients. By moving three sodium ions out and two potassium ions in, the pump contributes to a net negative charge inside the cell, which is vital for various cellular processes including nerve impulse transmission and muscle contraction. Understanding this mechanism is fundamental in physiology, as it underpins many physiological responses and homeostatic processes in the body.