The sodium potassium pump is the process of moving sodium, Na+, and potassium, K+, ions across the cell membrane, which is a form of active transport. Since it is an active transport process it requires ATP (energy). For each ATP the pump breaks down, two K+ ions are transported into the cell and three Na+ ions are transported out. The pump is very important for many reasons, one being maintaining a balance between ions. It also functions to maintain the electrical charge of a cell, especially in muscle and nerve cells. During muscle contraction potassium exits the cell and sodium enters which causes a change in electrical charge, and muscle contraction. As you could assume a lack of potassium would first affect the muscles and the nerves.
