1. The Na+−K+ pump can bind ATP only after the pump The N a + − K + pump can bind ATP only after the pump . 2. The Na+−K+ pump binds The N a + − K + pump binds when the pump is in its dephosphorylated state. 3. The Na+−K+ pump transports The N a + − K + pump transports from the extracellular fluid to the cytoplasm. from the extracellular fluid to the cytoplasm. 4. The Na+−K+ pump binds ATP when the pump is in its The N a + − K + pump binds ATP when the pump is in its state.

The process of the displacement of sodium and potassium ions through the cell membrane is an active transport process that involves the hydrolysis of ATP to provide the necessary energy. An enzyme known as Na + / K + -ATPase is involved. This process is responsible for keeping the large excess of Na + ions out of the cell and the large excess of K + ions inside the cell. A cycle of the transport process is outlined below. The transport of three Na + to the outside of the cell and the transport of two K + ions to the interior is carried out. This unbalanced load transfer contributes to the separation of charge across the membrane. The sodium-potassium pump is an important contributor to the action potential produced by nerve cells. This pump is called a P-type ion pump, because the interactions of ATP phosphorylates the transport protein, and causes a change in its conformation.