QS Study

Importance of Sodium-Potassium Pump or Na+ -K+ Pump in Controlling Cell Volume

Sodium-Potassium Pump is the process of moving sodium and potassium ions across the cell membrane is an active transport process involving the hydrolysis of ATP to provide the necessary energy. Inside the cell are a large number of proteins and other organic compounds that cannot escape from the cell. Most of these are negatively charged and therefore coiled around them are a large number of positive ions as well. It accomplishes the transport of three Na+ to the outside of the cells and the transport of two K+ ions to the inside. This unbalanced charge transfer contributes to the separation of charge across the membrane. The sodium-potassium pump is an important contributor to action potential produced by nerve cells.

All these substances then tend to cause osmosis of water to the interior of the cell. Unless this is checked, the cell will swell indefinitely until it bursts.

  • Na+ – K+ pump pumps 3 Na+ to the outside of the cell for every 2K+ pumped to the interior.
  • The cell membrane is far less permeable to Na+ than for K+. So, once Na+ are on the outside they have strong tendency to stay there.
  • The sodium-potassium pump also functions to maintain the electrical charge within the cell. This is particularly important for muscle and nerve cells.
  • It is vital to numerous bodily processes, such as nerve cell signaling, heart contractions, and kidney functions.

Thus, there is a continual net loss of ions out of the cell which also carries water out of cells.