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About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium. All 11 are necessary for life. The remaining elements are trace elements, of which more than a dozen are ...
Oxygen. cubic (cP16) Oxygen is a chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and a potent oxidizing agent that readily forms oxides with most elements as well as with other compounds.
Ozone (/ ˈoʊzoʊn /) (or trioxygen) is an inorganic molecule with the chemical formula O. 3. It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope O. 2, breaking down in the lower atmosphere to O.
Typical eukaryotic cell. Cellular respiration is the process by which biological fuels are oxidized in the presence of an inorganic electron acceptor, such as oxygen, to drive the bulk production of adenosine triphosphate (ATP), which contains energy. Cellular respiration may be described as a set of metabolic reactions and processes that take ...
Respiratory quotient. The respiratory quotient (RQ or respiratory coefficient) is a dimensionless number used in calculations of basal metabolic rate (BMR) when estimated from carbon dioxide production. It is calculated from the ratio of carbon dioxide produced by the body to oxygen consumed by the body, when the body is in a steady state.
The concentration of pure osmium tetroxide (molar mass = 254.23 g/mol) is c(OsO 4) = 5.1 kg/L / 254.23 g/mol = 20.1 mol/L. A typical protein in bacteria, such as E. coli, may have about 60 copies, and the volume of a bacterium is about 10 −15 L. Thus, the number concentration C is C = 60 / (10 −15 L) = 6 × 10 16 L −1. The molar ...
Oxygen compounds. Water (H 2 O) is the most familiar oxygen compound. The oxidation state of oxygen is −2 in almost all known compounds of oxygen. The oxidation state −1 is found in a few compounds such as peroxides. Compounds containing oxygen in other oxidation states are very uncommon: − 1⁄2 (superoxides), − 1⁄3 (ozonides), 0 ...
Molecular oxygen is a good terminal electron acceptor because it is a strong oxidizing agent. The reduction of oxygen does involve potentially harmful intermediates. [ 81 ] Although the transfer of four electrons and four protons reduces oxygen to water, which is harmless, transfer of one or two electrons produces superoxide or peroxide anions ...