Potassium leak channel

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The potassium leak channel is one of the major components that maintains the membrane potential in animal cells. A membrane potential is created by the difference in electrical charge on either side of a membrane. This difference in electrical potential is caused by the sodium-potassium pump and the diffusion of K+ ions through the potassium leak channel. The Na+-K+ channel pumps three Na+ out of the cell for every two K+ ions it pumps in. This creates a chemical gradient for the K+, which can move freely back across the membrane via the potassium leak channel. On top of this there is an electrical gradient acting on the K+ whereby the inside of the cell is more negative than the ouside. K+ are therefore attracted back in to the cell down this electrical gradient. Eventually an equilibrium is acheived between the electrical and chemical gradient of the K+. When the membrane is in this state it is known as the resting membrane potential and the relative negative charge of the inside cell created by the potassium leak channel and Na+-K+ pump allows an action potential to be created[1]

Functions - In excitable cells such as neurons, they set the resting membrane potential.

References

  1. Bruce Alberts, Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts, Peter Walter, (2008) Molecular biology of the cell, fifth edition, New York, Garland Science, Page 669
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