Final answer:
The sodium-potassium pump releases potassium ions within the cell, and through its function, it plays a critical role in creating a net negative charge inside the cell by expelling more sodium ions than it takes in potassium ions.
Step-by-step explanation:
The sodium-potassium pump releases potassium ions within the cell. This pump is essential for maintaining the correct concentration gradients of sodium and potassium across the cell membrane, which in turn contributes to the cell's resting membrane potential. The pump actively transports three sodium ions out of the cell for every two potassium ions imported, which leads to a net loss of positive charge inside the cell and thus contributes to the negative charge inside the cell.
The activity of the sodium-potassium pump is also vital for many cellular processes, including nerve impulse transmission and muscle contraction. ATP is necessary for the sodium-potassium pump to function; it provides the energy needed for the pump to change shape and move the ions across the membrane. Without ATP, the pump would not work correctly, and essential cellular functions could be disrupted.