What triggers the change in shape of the intrinsic protein associated with the sodium-potassium pump?

The change in shape of the intrinsic protein associated with the sodium-potassium pump is primarily triggered by the presence or absence of phosphate. The sodium-potassium pump operates through a mechanism known as phosphorylation. When sodium ions are bound to the pump, ATP is hydrolyzed, resulting in the transfer of a phosphate group to the protein. This phosphorylation causes a conformational change in the protein structure, allowing the pump to change its shape and subsequently release sodium ions outside the cell while taking in potassium ions from the outside environment.

This process is essential for maintaining the electrochemical gradients across the cell membrane, which are vital for various cellular functions, including nerve impulse transmission and muscle contraction. The role of phosphate in inducing this conformational shift is a crucial aspect of how the pump functions effectively in transporting ions against their concentration gradients.