Editing Proton pump (section)

==ATP-driven proton pumps==
{{Main|Proton ATPase}}

[[Proton ATPase|Proton pumps driven by adenosine triphosphate (ATP)]] (also referred to as proton ATPases or {{chem|H|+}}-ATPases) are proton pumps driven by the hydrolysis of [[adenosine triphosphate]] (ATP). Three classes of proton ATPases are found in nature. In a single cell (for example those of fungi and plants), representatives from all three groups of proton ATPases may be present.{{Citation needed|date=August 2023}}

===P-type proton ATPase===
{{Main|Plasma membrane H+-ATPase}}

The [[Plasma membrane H+-ATPase|plasma membrane {{chem|H|+}}-ATPase]] is a single subunit P-type ATPase found in the plasma membrane of [[plants]], [[fungi]], [[protists]] and many [[prokaryotes]].{{Citation needed|date=August 2023}}

The [[Plasma membrane H+-ATPase|plasma membrane {{chem|H|+}}-ATPase]] creates the [[electrochemical gradients]] in the [[plasma membrane]] of [[plants]], [[fungi]], [[protists]], and many [[prokaryotes]]. Here, proton gradients are used to drive [[Secondary active transport|secondary transport]] processes. As such, it is essential for the uptake of most [[metabolites]], and also for responses to the environment (e.g., movement of leaves in plants).{{Citation needed|date=August 2023}}

Humans (and probably other mammals) have a gastric [[hydrogen potassium ATPase]] or H<sup>+</sup>/K<sup>+</sup> ATPase that also belongs to the [[P-type ATPase|P-type ATPase family]]. This enzyme functions as the proton pump of the [[stomach]], primarily responsible for the acidification of the stomach contents (see [[gastric acid]]).{{Citation needed|date=August 2023}}

===V-type proton ATPase===
{{Main|V-ATPase}}

The [[V-ATPase|V-type proton ATPase]] is a multi-subunit enzyme of the [[V-ATPase|V-type]]. It is found in various different membranes where it serves to acidify [[Organelle|intracellular organelles]] or the [[Cell membrane|cell exterior]].{{Citation needed|date=August 2023}}

===F-type proton ATPase===
{{Main|F-ATPase}}

The [[ATP synthase|F-type proton ATPase]] is a multi-subunit enzyme of the [[F-ATPase|F-type]]  (also referred to as [[ATP synthase]] or F<sub>O</sub>F<sub>1</sub> ATPase). It is found in the mitochondrial inner membrane where it functions as a proton transport-driven [[ATP synthase]].

In [[mitochondria]], [[electrochemistry|reducing equivalents]] provided by [[electron transfer chain|electron transfer]] or [[photosynthesis]] power this translocation of protons. For example, the translocation of protons by [[cytochrome c oxidase]] is powered by reducing equivalents provided by reduced [[cytochrome c]]. ATP itself powers this transport in the [[plasma membrane]] proton ATPase and in the [[transmembrane ATPase|ATPase]] proton pumps of other cellular membranes.{{Citation needed|date=August 2023}}

The F<sub>o</sub>F<sub>1</sub> [[ATP synthase]] of mitochondria, in contrast, usually conduct protons from high to low concentration across the membrane while drawing energy from this flow to synthesize ATP. Protons translocate across the inner mitochondrial membrane via proton wire. This series of conformational changes, channeled through the a and b subunits of the F<sub>O</sub> particle, drives a series of conformational changes in the stalk connecting the F<sub>O</sub> to the F<sub>1</sub> subunit. This process effectively couples the translocation of protons to the mechanical motion between the Loose, Tight, and Open states of F<sub>1</sub> necessary to phosphorylate ADP.{{Citation needed|date=August 2023}}

In [[bacteria]] and ATP-producing organelles other than mitochondria, [[electrochemistry|reducing equivalents]] provided by [[electron transfer chain|electron transfer]] or [[photosynthesis]] power the translocation of protons.{{Citation needed|date=August 2023}}

CF<sub>1</sub> ATP [[ligase]] of [[chloroplast]]s correspond to the human F<sub>O</sub>F<sub>1</sub> ATP synthase in plants.{{Citation needed|date=August 2023}}