Sodium pump

The sodium pump, or Na-K ATPase, is found in all cells. It is an integral membrane protein, formed by a tetrameric complex of two polypeptides: two transmembrane catalytic alpha subunits and two glycoprotein regulatory beta subunits.

The catalytic subunits form the gated channel and possess binding sites for Na+ and adenosine S'-triphosphate (ATP) on the intracellular surface, and for K+ and ouabain on the extracellular surface. They have phosphorylation sites and span the plasma membrane ten times. The beta subunit comprises a single membrane-spanning domain and has three extracellular glycosylation sites.

It requires oxygen for the provision of the substrate, ATP. It is electrogenic, extruding 3 Na+ ions for every 2 K+ ions (coupling ratio of 3:2). The pump is an antiport, transporting two different ions in opposite directions across the membrane. Sodium Na+ ion pumped out of the cell is used to drive active co-transport systems.

Was this article helpful?

0 0
Tips and Tricks For Boosting Your Metabolism

Tips and Tricks For Boosting Your Metabolism

So maybe instead of being a pencil-neck dweeb, youre a bit of a fatty. Well, thats no problem either. Because this bonus will show you exactly how to burn that fat off AS you put on muscle. By boosting your metabolism and working out the way you normally do, you will get rid of all that chub and gain the hard, rippled muscles youve been dreaming of.

Get My Free Ebook

Post a comment