What is the main function of the Na+/K+ ATPase pump in cells?

What is the main function of the Na+/K+ ATPase pump in cells?

• A. It maintains Na+ and K+ gradients across the plasma membrane by pumping 3 Na+ out and 2 K+ in per ATP hydrolyzed.
• B. It generates glucose from lactate.
• C. It transports chloride ions to regulate pH.
• D. It synthesizes ATP from ADP.

Answer: (A)

The main concept is that this pump uses energy from ATP to move ions against their gradients, establishing the essential Na+ and K+ electrochemical gradients across the plasma membrane. It binds 3 Na+ inside the cell, uses one ATP molecule to drive a conformational change that dumps those Na+ outside, then binds 2 K+ outside and returns them inside, releasing them with another conformational change. The net result is 3 Na+ out and 2 K+ in per ATP hydrolyzed. This gradient underpins the resting membrane potential, helps regulate cell volume, and drives secondary active transport of other solutes. It’s not about glucose production, chloride transport for pH, or ATP synthesis by ATP synthase, so those functions aren’t what this pump does.

The main concept is that this pump uses energy from ATP to move ions against their gradients, establishing the essential Na+ and K+ electrochemical gradients across the plasma membrane. It binds 3 Na+ inside the cell, uses one ATP molecule to drive a conformational change that dumps those Na+ outside, then binds 2 K+ outside and returns them inside, releasing them with another conformational change. The net result is 3 Na+ out and 2 K+ in per ATP hydrolyzed. This gradient underpins the resting membrane potential, helps regulate cell volume, and drives secondary active transport of other solutes. It’s not about glucose production, chloride transport for pH, or ATP synthesis by ATP synthase, so those functions aren’t what this pump does.