Transmembrane ATPase

Transmembrane ATPases are integral membrane proteins and active transporters, which transport one or more ions or other solutes between the two sides of a biological membrane in concert with the hydrolysis of ATP. The category includes cotransporters and pumps, some of which cause a net flow of charge (electrogenic pumps) and others of which do not (non-electrogenic pumps or transporters). An important example is the sodium-potassium exchanger ("Na+/K+ATPase"), which maintains the ionic concentration balance that maintains the cell potential. All of these enzymes require ATP to accomplish transport, because they transport solutes in the direction opposite to their thermodynamically preferred direction of movement--from a side of the membrane where they are in low concentration to a side where they are in high concentration. The coupling between ATP hydrolysis and transport is a more or less strict chemical reaction in which a prescribed number of each solute molecule is transported for every one ATP molecule that is hydrolyzed.

ATP Synthetase or just ATP Synthase, is an anabolic enzyme which harnesses the energy of small particles such as protons as they diffuse across a membrane to bind a molecule of ADP (Adenosine Diphosphate) to a molecule of inorganic phosphate to create a molecule of ATP (Adenosine Triphosphate).

This system is found in many different metabolical reactions in a plethora of organisms. One example is in the light reactions of photosynthesis, where the energy of protons acquired from the splitting of water molecules is harnessed to create ATP.