Final answer:
The cellular process when a transport protein uses ATP to pump sodium ions across a membrane is called active transport, specifically through the sodium-potassium pump. This pump moves sodium out and potassium into the cell using energy from ATP.
Step-by-step explanation:
The type of cellular process that occurs when a transport protein utilizes ATP to actively pump sodium ions across a membrane is known as active transport. Specifically, this is carried out by a mechanism called the sodium-potassium pump. This pump functions to move sodium ions out of the cell and potassium ions into the cell against their concentration gradients, an action that requires energy supplied by ATP.
During this process, three sodium ions inside the cell bind to the pump and are released outside when ATP transfers a phosphate group to the pump, causing a change in its shape. Then, two potassium ions from outside the cell bind to the pump and are transported inside when the pump returns to its original shape.
This cycle is essential for maintaining proper concentrations of sodium and potassium ions within and outside of cells, which is crucial for various physiological processes such as nerve impulse transmission and muscle contraction.