The sodium-potassium ATPase is an essential enzyme found in the membranes of cells. It helps maintain the balance of sodium and potassium ions inside and outside the cell, which is crucial for various cellular functions, including nerve impulse transmission and muscle contraction. The enzyme uses energy from adenosine triphosphate (ATP) to pump three sodium ions out of the cell and two potassium ions into the cell. This process creates an electrochemical gradient, which is vital for maintaining the cell's resting potential. By regulating ion concentrations, the sodium-potassium ATPase plays a key role in cellular homeostasis and overall cell health.