sodium potassium ATPasemedical dictionary

<enzyme>

<cell biology> A major transport protein of the plasma membrane. A multi unit enzyme, it moves 3 sodium ions out of the cell and 2 potassium ions in, for each ATP hydrolysed. The sodium gradient established is used for several purposes (see facilitated diffusion, action potential), while the potassium gradient is dissipated through the potassium leak channel. Must not be confused with a sodium channel.

This entry appears with permission from the Dictionary of Cell and Molecular Biology

(11 Mar 2008)