gen-briefly-explain-the-sodium-potassium-pump-and-one-common-mis-2157

Briefly explain the sodium-potassium pump and one common misconception about it.

## The Sodium-Potassium Pump The sodium-potassium pump (Na⁺/K⁺-ATPase) is a protein in cell membranes that actively transports ions against their concentration gradients. It moves **3 sodium ions out** of the cell and **2 potassium ions into** the cell, using energy from ATP hydrolysis. This maintains crucial concentration differences: high K⁺ inside cells and high Na⁺ outside. This pump is essential for: - Maintaining cell volume - Enabling nerve impulses - Supporting other transport processes - Contributing to the resting membrane potential ## Common Misconception **Misconception**: The pump directly creates the entire resting membrane potential through its 3:2 transport ratio. **Reality**: While the pump is *electrogenic* (creates a small negative charge of ~-5 to -10 mV due to unequal ion exchange), the bulk of the resting potential (~-70 mV) comes from **passive potassium leak channels**. The pump's main role is maintaining the concentration gradients that allow these leak channels to generate the potential. Think of it this way: the pump sets up the conditions, but passive ion flow does most of the electrical work.