The primary function of the K-ATPase pump is to move three sodium ions out of the cell and two potassium ions into the cell against their concentration gradients. This process is powered by the hydrolysis of ATP. The pump undergoes conformational changes during this cycle, which allows it to bind and release ions effectively. The cycle can be summarized in the following steps:
1. Binding of three sodium ions from the intracellular space. 2. Phosphorylation of the pump by ATP, leading to a conformational change. 3. Release of sodium ions into the extracellular space. 4. Binding of two potassium ions from the extracellular space. 5. Dephosphorylation of the pump, reverting it to its original conformation. 6. Release of potassium ions into the intracellular space.
