Editing Cellular respiration (section)

==Anaerobic respiration==
{{Main|Anaerobic respiration}}
Cellular respiration is the process by which biological fuels are oxidised in the presence of an inorganic electron acceptor, such as oxygen, to produce large amounts of energy and drive the bulk production of ATP.{{cn|date=May 2025}}

'''Anaerobic respiration''' is used by microorganisms, either [[bacteria]] or [[archaea]], in which neither oxygen (aerobic respiration) nor pyruvate derivatives (fermentation) is the final electron acceptor.  Rather, an inorganic acceptor such as [[sulfate]] ({{chem2|SO4(2-)}}), [[nitrate]] ({{chem2|NO3-}}), or [[sulfur]] (S) is used.<ref>{{cite web|url= https://courses.lumenlearning.com/boundless-microbiology/chapter/anaerobic-respiration/|title=Anaerobic Respiration-Electron Donors and Acceptors in Anaerobic Respiration |author=Lumen Boundless Microbiology|website=courses.lumenlearning.org |publisher=Boundless.com |access-date=November 19, 2020 |quote="Anaerobic respiration is the formation of ATP without oxygen. This method still incorporates the respiratory electron transport chain, but without using oxygen as the terminal electron acceptor. Instead, molecules such as sulfate ({{chem2|SO4(2-)}}), nitrate ({{chem2|NO3-}}), or sulfur (S) are used as electron acceptors"}}</ref> Such organisms could be found in unusual places such as underwater caves or near [[hydrothermal vents]] at the bottom of the ocean.,<ref name=Mannion/>{{rp|66–68}} as well as in anoxic soils or sediment in wetland ecosystems.

In July 2019, a scientific study of [[Kidd Mine]] in Canada discovered [[sulfur-breathing organisms]] which live {{convert|7900|ft|m|comma=5|abbr=off|sp=us}} below the surface. These organisms are also remarkable because they consume minerals such as [[pyrite]] as their food source.<ref>{{cite journal|doi=10.1080/01490451.2019.1641770 | volume=36 | title='Follow the Water': Hydrogeochemical Constraints on Microbial Investigations 2.4 km Below Surface at the Kidd Creek Deep Fluid and Deep Life Observatory | year=2019 | journal=Geomicrobiology Journal | pages=859–872 | last1 = Lollar | first1 = Garnet S. | last2 = Warr | first2 = Oliver | last3 = Telling | first3 = Jon | last4 = Osburn | first4 = Magdalena R. | last5 = Sherwood Lollar | first5 = Barbara| issue=10 | bibcode=2019GmbJ...36..859L | s2cid=199636268 }}</ref><ref>[https://deepcarbon.net/worlds-oldest-groundwater-supports-life-through-water-rock-chemistry World's Oldest Groundwater Supports Life Through Water-Rock Chemistry] {{Webarchive|url=https://web.archive.org/web/20190910013319/https://deepcarbon.net/worlds-oldest-groundwater-supports-life-through-water-rock-chemistry |date=2019-09-10 }}, July 29, 2019, deepcarbon.net.</ref><ref>[https://www.nbcnews.com/mach/science/strange-life-forms-found-deep-mine-point-vast-underground-galapagos-ncna1050906 Strange life-forms found deep in a mine point to vast 'underground Galapagos'] {{Webarchive|url=https://web.archive.org/web/20190909104558/https://www.nbcnews.com/mach/science/strange-life-forms-found-deep-mine-point-vast-underground-galapagos-ncna1050906 |date=2019-09-09 }}, By Corey S. Powell, Sept. 7, 2019, nbcnews.com.</ref>