Sodium-potassium-ATPase pump

Definition

The sodium-potassium-ATPase pump is an enzyme found in the cell membrane that helps maintain cellular electrochemical gradients by actively transporting sodium out of the cell and potassium into the cell. This process uses energy derived from ATP hydrolysis.

5 Must Know Facts For Your Next Test

1. The pump moves three sodium ions out of the cell and two potassium ions into the cell per ATP molecule hydrolyzed.
2. It plays a crucial role in maintaining resting membrane potential and cellular homeostasis.
3. Inhibition of this pump can lead to increased intracellular sodium levels, affecting cellular functions and potentially leading to conditions like hyperkalemia.
4. Cardiac glycosides, such as digoxin, inhibit the sodium-potassium-ATPase pump, which can be used therapeutically to treat heart failure.
5. Proper function of this pump is essential for nerve impulse transmission, muscle contraction, and overall fluid balance.

Review Questions

• How many sodium ions are transported out of the cell by the sodium-potassium-ATPase pump for each ATP molecule hydrolyzed?
• What effect does inhibition of the sodium-potassium-ATPase pump have on intracellular potassium levels?
• Why is the sodium-potassium-ATPase pump important for maintaining resting membrane potential?

Related terms

Resting Membrane Potential: The voltage difference across a cell's plasma membrane in its resting state.

Cardiac Glycosides: A class of organic compounds that increase cardiac contractility by inhibiting the sodium-potassium-ATPase pump.

Hyperkalemia: A condition characterized by elevated levels of potassium in the blood, which can be influenced by impaired function of the sodium-potassium-ATPase pump.