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There are 4 glossary search results for:   atpase




Definition:
Electrogenic pumps are primary active transporters that hydrolyze ATP and use the energy released from ATP hydrolysis to transport ions across biological membranes leading to the translocation of net charge across the membrane.

For example, the Na+/K+ ATPase (sodium pump) is an electrogenic pump because during every transport cycle, it transports 3 Na+ ions out of the cell and 2 K+ ions into the cell. This leads to the movement of one net positive charge out of the cell making this process electrogenic.

Related glossary terms/phrases:
Electrogenic



Definition:
An electrogenic transport process is one that leads to the translocation of net charge across the membrane. For example, ion channels such as Na+, K+, Ca2+, and Cl channels are electrogenic.

The Na+/K+ ATPase is electrogenic because for every ATP molecule hydrolyzed, 3 Na+ ions are transported out of the cell and 2 K+ ions are transported into the cell (leading to the translocation of one net positive charge out of the cell).

Many secondary active transporters are also electrogenic. For example, the Na+/glucose cotransporter (found in the small intestine and kidney proximal tubules), transports 2 Na+ ions and 1 glucose molecule into the cell across the plasma membrane (leading to the translocation of two net positive charges into the cell per transport cycle).



Definition:
Ouabain binds to and inhibits the transport activity of the Na+/K+/ATPase (i.e., sodium pump).

Ouabain is plant derived and belongs to the class of drugs referred to as cardiac glycosides. Similar to other cardiac glycosides, ouabain increase heart muscle contractility. However, ouabain is used only experimentally and not in humans (as for example digoxin is for the treatment of congestive heart failure).

There is some evidence that ouabain may be produced endogenously in humans.

Related glossary terms/phrases:
Vanadate

Other resources:
Ouabain (Wikipedia)



Definition:
An inhibitor of the Na+/K+/ATPase (i.e., sodium pump). The form commonly used for this purpose is sodium orthovanadate.

Related glossary terms/phrases:
Ouabain









Posted: Sunday, March 31, 2013
Last updated: Friday, August 28, 2015