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  2. Marine biogeochemical cycles - Wikipedia

    en.wikipedia.org/wiki/Marine_biogeochemical_cycles

    The word oxygen in the literature typically refers to molecular oxygen (O 2) since it is the common product or reactant of many biogeochemical redox reactions within the cycle. [37] Processes within the oxygen cycle are considered to be biological or geological and are evaluated as either a source (O 2 production) or sink (O 2 consumption). [36 ...

  3. Iron in biology - Wikipedia

    en.wikipedia.org/wiki/Iron_in_biology

    Iron-containing proteins participate in transport, storage and use of oxygen. [1] Iron proteins are involved in electron transfer . [ 5 ] The ubiquity of Iron in life has led to the Iron–sulfur world hypothesis that iron was a central component of the environment of early life.

  4. Zeolite - Wikipedia

    en.wikipedia.org/wiki/Zeolite

    Zeolite-based oxygen concentrator systems are widely used to produce medical-grade oxygen. The zeolite is used as a molecular sieve to create purified oxygen from air using its ability to trap impurities, in a process involving the adsorption of nitrogen, leaving highly purified oxygen and up to 5% argon.

  5. Oxygen - Wikipedia

    en.wikipedia.org/wiki/Oxygen

    Oxygen is the third most abundant chemical element in the universe, after hydrogen and helium. [68] About 0.9% of the Sun's mass is oxygen. [19] Oxygen constitutes 49.2% of the Earth's crust by mass [69] as part of oxide compounds such as silicon dioxide and is the most abundant element by mass in the Earth's crust.

  6. Mineral - Wikipedia

    en.wikipedia.org/wiki/Mineral

    Both iron and magnesium are in octahedral by oxygen. Other mineral species having this structure exist, such as tephroite, Mn 2 SiO 4. [131] The garnet group has a general formula of X 3 Y 2 (SiO 4) 3, where X is a large eight-fold coordinated cation, and Y is a smaller six-fold coordinated cation. There are six ideal endmembers of garnet ...

  7. Copper in biology - Wikipedia

    en.wikipedia.org/wiki/Copper_in_biology

    Copper proteins have diverse roles in biological electron transport and oxygen transportation, processes that exploit the easy interconversion of Cu(I) and Cu(II). [2] Copper is essential in the aerobic respiration of all eukaryotes. In mitochondria, it is found in cytochrome c oxidase, which is the last protein in oxidative phosphorylation.

  8. Hemocyanin - Wikipedia

    en.wikipedia.org/wiki/Hemocyanin

    Hemocyanin is made of many individual subunit proteins, each of which contains two copper atoms and can bind one oxygen molecule (O 2). Each subunit weighs about 75 kilodaltons (kDa). Subunits may be arranged in dimers or hexamers depending on species; the dimer or hexamer complex is likewise arranged in chains or clusters with weights ...

  9. Heme - Wikipedia

    en.wikipedia.org/wiki/Heme

    Binding of oxygen to a heme prosthetic group. Heme (American English), or haem (Commonwealth English, both pronounced /hi:m/ HEEM), is a ring-shaped iron-containing molecular component of hemoglobin, which is necessary to bind oxygen in the bloodstream. It is composed of four pyrrole rings with 2 vinyl and 2 propionic acid side chains. [1]