Oxygen cycle refers to the movement of oxygen through the atmosphere (air), biosphere (plants and animals) and the lithosphere (the Earth’s crust). The oxygen cycle demonstrates how free oxygen is made available in each of these regions, as well as how it is used. The oxygen cycle is the biogeochemical cycle of oxygen atoms between different oxidation states in ions, oxides, and molecules through redox reactions within and between the spheres/reservoirs of the planet Earth.[1] The word oxygen in the literature typically refers to the most common oxygen allotrope, elemental/diatomic oxygen (O2), as it is a common product or reactant of many biogeochemical redox reactions within the cycle.[2] Processes within the oxygen cycle are considered to be biological or geological and are evaluated as either a source (O2 production) or sink (O2 consumption).[1][2]
Oxygen is one of the most common elements on Earth and represents a large portion of each main reservoir. By far the largest reservoir of Earth's oxygen is within the silicate and oxide minerals of the crust and mantle (99.5% by weight).[6] The Earth's atmosphere, hydrosphere, and biosphere together hold less than 0.05% of the Earth's total mass of oxygen. Besides O2, additional oxygen atoms are present in various forms spread throughout the surface reservoirs in the molecules of biomass, H2O, CO2, HNO3, NO, NO2, CO, H2O2, O3, SO2, H2SO4, MgO, CaO, Al2O3, SiO2, and PO4.[7]
^ abcKnoll AH, Canfield DE, Konhauser K (2012). "7". Fundamentals of geobiology. Chichester, West Sussex: John Wiley & Sons . pp. 93–104. ISBN 978-1-118-28087-4. OCLC 793103985.
^ abcPetsch ST (2014). "The Global Oxygen Cycle". Treatise on Geochemistry. Elsevier. pp. 437–473. doi:10.1016/b978-0-08-095975-7.00811-1. ISBN 978-0-08-098300-4.
^Keeling RF, Shertz SR (August 1992). "Seasonal and interannual variations in atmospheric oxygen and implications for the global carbon cycle". Nature. 358 (6389): 723–727. Bibcode:1992Natur.358..723K. doi:10.1038/358723a0. S2CID 4311084.
^Holland HD (2002). "Volcanic gases, black smokers, and the great oxidation event". Geochimica et Cosmochimica Acta. 66 (21): 3811–3826. Bibcode:2002GeCoA..66.3811H. doi:10.1016/S0016-7037(02)00950-X.
^Lasaga AC, Ohmoto H (2002). "The oxygen geochemical cycle: dynamics and stability". Geochimica et Cosmochimica Acta. 66 (3): 361–381. Bibcode:2002GeCoA..66..361L. doi:10.1016/S0016-7037(01)00685-8.
^Falkowski PG, Godfrey LV (August 2008). "Electrons, life and the evolution of Earth's oxygen cycle". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 363 (1504): 2705–16. doi:10.1098/rstb.2008.0054. PMC 2606772. PMID 18487127.
^Cite error: The named reference :2 was invoked but never defined (see the help page).
Oxygencycle refers to the movement of oxygen through the atmosphere (air), biosphere (plants and animals) and the lithosphere (the Earth’s crust). The...
The CNO cycle (for carbon–nitrogen–oxygen; sometimes called Bethe–Weizsäcker cycle after Hans Albrecht Bethe and Carl Friedrich von Weizsäcker) is one...
on oxygen-containing molecules such as carbon dioxide. The unusually high concentration of oxygen gas on Earth is the result of the oxygencycle. This...
nutrients is cyclic. Mineral cycles include the carbon cycle, sulfur cycle, nitrogen cycle, water cycle, phosphorus cycle, oxygencycle, among others that continually...
The phosphorus cycle is the biogeochemical cycle that involves the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. Unlike...
oxygen isotopic values it may be possible to use oxygen to trace the sulfur cycle. Biological sulfate reduction preferentially selects lighter oxygen...
The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial...
The water cycle (or hydrologic cycle or hydrological cycle), is a biogeochemical cycle that involves the continuous movement of water on, above and below...
Oxygen isotope ratio cycles are cyclical variations in the ratio of the abundance of oxygen with an atomic mass of 18 to the abundance of oxygen with an...
An oxygen concentrator is a device that concentrates the oxygen from a gas supply (typically ambient air) by selectively removing nitrogen to supply an...
into a molecule of O2 and an individual atom of oxygen, a continuing process called the ozone-oxygencycle. Chemically, this can be described as: O 2 + h...
oxidized to Fe3+ in the presence of oxygen, and the reduction of Fe3+ to Fe2+ by iron-sulfide minerals. The biological cycling of Fe2+ is done by iron oxidizing...
and oxygencycles through processes such as photosynthesis. The marine carbon cycle is also biologically tied to the nitrogen and phosphorus cycles by...
to about the mass of the Sun. The second process, the carbon–nitrogen–oxygencycle, which was also considered by Carl Friedrich von Weizsäcker in 1938,...
oxygen within and between its three main reservoirs: the atmosphere, the biosphere, and the lithosphere. The main driving factor of the oxygencycle is...
describe their time evolution can be automatically constructed. Oxygencycle Ozone-oxygencycle Paleoclimatology Scientific Assessment of Ozone Depletion Tropospheric...
[citation needed] The citric acid cycle is also called the Krebs cycle or the tricarboxylic acid cycle. When oxygen is present, acetyl-CoA is produced...
Sydney Chapman in 1930, and is known as the Chapman cycle or ozone–oxygencycle. Molecular oxygen absorbs high energy sunlight in the UV-C region, at...
biogeochemical cycles for the elements calcium, carbon, hydrogen, mercury, nitrogen, oxygen, phosphorus, selenium, and sulfur; molecular cycles for water and...
V̇O2 max (also maximal oxygen consumption, maximal oxygen uptake or maximal aerobic capacity) is the maximum rate of oxygen consumption attainable during...
When the supply of oxygen is sufficient, this energy comes from feeding pyruvate, one product of glycolysis, into the citric acid cycle, which ultimately...
chemical cycles which are either driven by or influence biological activity. Particular emphasis is placed on the study of carbon, nitrogen, oxygen, sulfur...
The chlorine cycle (Cl) is the biogeochemical cycling of chlorine through the atmosphere, hydrosphere, biosphere, and lithosphere. Chlorine is most commonly...
Nitrogenases are rapidly degraded by oxygen. For this reason, many bacteria cease production of the enzyme in the presence of oxygen. Many nitrogen-fixing organisms...
The staged combustion cycle (sometimes known as topping cycle, preburner cycle, or closed cycle) is a power cycle of a bipropellant rocket engine. In...