Question

In detail, describe the mechanism of the sodium/potassium pump. To describe the mechanism means to explain all steps involved in the operation of the pump in order. Your answer should do more than just provide a definition of the pump.

Answer 1

Sodium potassium pump is a protein pump found in the cell membrane of nerve cells. It act to transport sodium and potassium actively using ATP across the membrane in aratio of 3 sodium ions out of membrane to 2 potassium ions taken into the membrane.

Steps of sodium potassium pump:-

1. Cytoplasmic sodium binds to sodium potassium pump
2. Sodium binding stimulate the phosphorylation of ATP
3. Phosphorylation lead to a change in the shape of the protein, reducing affinity for Na^​​​+ which is released outside
4. The new shape has high affinity to potassium, which binds on extracellular surface and triggers the release of phosphate group
5. Loss of phosphate group retores the original shape of protein, which has lower affinity for potassium
6. K+ is released and the affinity for sodium is high again and the cycle repeats