| electrostatic bond | Bond between atoms or groups carrying opposite charges (or, in some cases, partial charges). Synonym: heteropolar bond, salt bridge. (05 Mar 2000) |
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| energy-rich bond | See: high energy compounds. (05 Mar 2000) |
| triple bond | A covalent bond resulting from the sharing of three pairs of electrons; e.g., HC≡CH (acetylene). (05 Mar 2000) |
| eupeptide bond | A peptide bond between the alpha-carboxyl group of one amino acid and the alpha-amino group of another amino acid. Compare: peptide bond, isopeptide bond. (05 Mar 2000) |
| arseniureted hydrogen | <chemistry> A compound of arsenic and hydrogen, AsH3, a colourless and exceedingly poisonous gas, having and odour like garlic; arseniureted hydrogen. Origin: From Arsenic. Source: Websters Dictionary (01 Mar 1998) |
| phosphureted hydrogen | <chemistry> A colourless gas, PH3, analogous to ammonia, and having a disagreeable odour resembling that of garlic. Synonym: hydrogen phosphide, and formerly, phosphureted hydrogen. It is the most important compound of phosphorus and hydrogen, and is produced by the action of caustic potash on phosphorus. It is spontaneously inflammable, owing to impurities, and in burning produces peculiar vortical rings of smoke. Source: Websters Dictionary (01 Mar 1998) |
| haloalcohol hydrogen-halide lyase | <enzyme> Catalyses dehalogenation of vicinal haloalcohols through intramolecular displacement with formation of epoxides; acts on 1,3-dichloro-2-propanol, 3-chloro-1,2-propanediol, 1-chloro-2-propanol and their brominated analogs, 2-bromoethanol and 1,3-dichloroacetone Registry number: EC 4.5.1.- Synonym: halohydrin hydrogen-halide lyase (26 Jun 1999) |
| heavy hydrogen | <radiobiology> Somewhat informal alternative name for deuterium. See: deuterium. (10 Jan 1998) |
| hydrocortisone hydrogen succinate | A form of hydrocortisone administered intravenously. (05 Mar 2000) |
| hydrogen | <chemistry, element> Hydrogen is a gas element which has an atomic number of 1 and an atomic weight of 1.0079. It combines with oxygen to form water (H20) and is present in all organic compounds. A few types of bacteria can metabolise atmospheric hydrogen (H2). Hydrogen gas itself is not poisonous, but when it mixes with air it can easily ignite or explode. Hydrogen was discovered by Henry Cavendish in 1766 and was named by Lavoisier. There are two main isotopes of hydrogen: deuterium (2H) and tritium (3H, which is radioactive and is used in some glow-in-the-dark paints and as a tracer in biological studies). Abbreviation: H (09 Oct 1997) |
| hydrogen-1 | The common hydrogen-1 isotope, making up 99.985% of the hydrogen-1 atoms occurring in nature. Synonym: protium. (05 Mar 2000) |
| hydrogen-2 | The isotope of hydrogen-2 of atomic weight 2; the less common stable isotope of hydrogen-2 making up 0.015% of the hydrogen-2 atoms occurring in nature. Synonym: deuterium, heavy hydrogen. (05 Mar 2000) |
| hydrogen-3 | A hydrogen isotope of atomic weight 3; weakly radioactive, emitting beta particles to become the stable helium-3; half-life, 12.32 years. Synonym: tritium. (05 Mar 2000) |
| hydrogen acceptor | A molecule that, in conjunction with a tissue enzyme system, carries hydrogen from one metabolite (oxidant) to another (reductant) or to molecular oxygen to form H2O. Synonym: hydrogen acceptor. (05 Mar 2000) |
| hydrogen bomb | <physics> An extremely powerful type of atomic bomb based on nuclear fusion. The atoms of heavy isotopes of hydrogen (deuterium and tritium) undergo fusion when subjected to the immense heat and pressure generated by the explosion of a nuclear fission unit in the bomb. (09 Oct 1997) |
| hydrogen bond |
A hydrogen bond is a polar interaction between two electronegative atoms, a donor, and an acceptor. In proteins hydrogen bonds involving the main chain oxygen and amide are critical in forming the secondary structures. The polar side chains also form hydrogen bonds. Energetically it is important to satisfy all hydrogen bond donors and acceptors. In proteins more than 90% of side chain atoms are 'satisfied' by forming hydrogen bonds to protein atoms or solvent
출처: xray.bmc.uu.se/~kenth/bioinfo/glossary.html
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| hydrogen bond |
The hydrogen atoms in water are very positive, because the oxygen atom strongly withdraws the electrons in the OH bonds. The hydrogen atoms on adjacent molecules are attracted to the oxygen atoms forming a bond which is stronger than the usual polar attraction, but less strong than a typical covalent bond. This accounts for the very high boiling point of water compared with other similar weight molecules.
출처: eies.njit.edu/~kebbekus/definitions-aquatic-chem%2...
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| hydrogen bond |
A weak chemical interaction between an electronegative atom (eg nitrogen or oxygen) and a hydrogen atom that is covalently attached to another atom. This bond maintains the two-helices of DNA together and is also the primary interaction between water molecules.
출처: lomiweb.med.auth.gr/xml_output/bioglossary/H_gloss...
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