Final answer:
The sodium-potassium pump uses ATP to transport three Na+ ions out and two K+ ions into the cell, maintaining low Na+ and high K+ concentrations inside the cell necessary for nerve impulse transmission and osmotic balance.
Step-by-step explanation:
The sodium-potassium pump, also known as Na+/K+ ATPase, is crucial in maintaining the electrochemical gradient across the cell membrane by keeping the internal concentration of Na+ low and K+ high. The pump operates by using energy derived from the hydrolysis of ATP to transport ions against their concentration gradients. For every one ATP molecule hydrolyzed, the pump moves three sodium ions (Na+) out of the cell and two potassium ions (K+) into the cell. This active transport process is essential for nerve cells, where it drives the electrical gradient necessary for nerve impulse transmission, and also helps maintain the osmotic balance required for cell stability.