Final answer:
The Na+/K+ ATPase utilizes active transport to maintain the asymmetry of the plasma membrane by moving Na+ out of the cell and K+ into the cell. Phosphorylation is essential for the pump's mechanism of action, enabling conformational changes and the binding and release of ions.
Step-by-step explanation:
The Na+/K+ ATPase, also known as the sodium-potassium pump, illustrates the asymmetry of the plasma membrane by actively transporting sodium ions (Na+) out of the cell and potassium ions (K+) into the cell. This creates a concentration gradient of Na+ and K+ across the membrane, with higher Na+ concentrations outside the cell and higher K+ concentrations inside the cell.
Phosphorylation plays a crucial role in the mechanism of action of this pump. When ATP is hydrolyzed by the ATPase domain of the pump, a phosphate group is transferred to the pump protein. This leads to a conformational change that allows the pump to bind three Na+ ions from the cytosol. The phosphorylation also induces further allosteric changes, resulting in the release of Na+ ions outside the cell. Subsequently, two K+ ions from the extracellular fluid are able to bind to the pump protein, causing the hydrolysis of the phosphate group and the restoration of the original conformation of the pump.