Question

Diagram a mechanism of action for the sodium potassium ATPase.

Answer 1

The process of transport of Na⁺ and K⁺ across the cell membrane is an example of active transport i.e. the transport of Na⁺ and K⁺ across the membrane require energy.

The requirement of energy is fulfil by the hydrolysis of ATP. In this process an enzyme is involved called Na⁺ /K-ATPase. Na⁺/K⁺ -ATPase is also known as Na⁺/K⁺ pump.

Basically Na⁺/K⁺ pump maintains the excess of Na⁺ ions outside of the cell and excess of K⁺ inside the cell.

The transport of Na⁺ and K⁺ with the help of Na⁺/K⁺ -ATPase is accomplished as follow:

1) Na⁺/K⁺ pump first bind with ATP followed by binding with three molecule of intracellular Na⁺

2) ATP gets hydrolysed and phosphorylate the pump. Phosphorylation of pump decreases the affinity of pump for Na⁺ ions that leads to release of Na⁺ ions outside of the cell.

3) Binding Na⁺/K⁺ pump with two extracellular K⁺ leads to dephosphorylation of the pump. Desphophorylation of the pump leads to achieving the original state of the pump that has less affinity of K⁺ leads to release of K⁺

The entire mechanism is shown in the below diagram