Which transport protein actively moves sodium out and potassium into the cell?

The sodium-potassium pump is a crucial transport protein that plays a vital role in maintaining the electrochemical gradient across the cell membrane. This pump uses ATP to actively transport sodium ions out of the cell while bringing potassium ions into the cell. Specifically, for every three sodium ions that are expelled, two potassium ions are imported, which contributes to a net negative charge inside the cell. This process is essential for numerous cellular functions, including maintaining osmotic balance, generating action potentials in neurons, and facilitating nutrient uptake.

The sodium-chloride pump primarily deals with the transport of sodium and chloride ions and does not specifically denote the movement of potassium. The calcium pump focuses on moving calcium ions out of the cell, while the potassium pump is often an informal term that might refer to the sodium-potassium pump but does not specify the active transport process involving both sodium and potassium effectively. Thus, the significance of the sodium-potassium pump in actively regulating ionic concentrations in the cell makes it the correct choice for this question.