| HF | Hageman factor; haplotype frequency; hard filled [capsule]; hay fever; head of fetus; head forward; ... |
|---|---|
| HPLC | high-performance liquid chromatography; high-power liquid chromatography; high-pressure liquid chrom... |
| HT | Hashimoto thyroiditis; hearing test; hearing threshold; heart; heart transplantation, heart transpla... |
| HEI | Health Effects Institute; high-energy intermediate; homogenous enzyme immunoassay; human embryonic i... |
| HEIR | health effects of ionizing radiation; high-energy ionizing radiation |
energetics
| carbon-carbon double bond isomerases | <enzyme> Enzymes that catalyze the shifting of a carbon-carbon double bond from one position to another within the same molecule. Registry number: EC 5.3.3 (12 Dec 1998) |
|---|---|
| pair bond | In animals, the social relationship established between a male and female for reproduction. It may include raising of young. (12 Dec 1998) |
| glycosidic bond | <biochemistry> A bond between a sugar andanother organic molecule by way of anintervening nitrogen or oxygen atom. (09 Oct 1997) |
| peptide bond | The amide linkage between the carboxyl group of one amino acid and the amino group of another. The linkage does not allow free rotation and can occur in cis or trans configuration, the latter the most common in natural peptides, except for links to the amino group of proline, which are always cis. (18 Nov 1997) |
| chemical bond | The link between two atoms within a molecule. Different types of chemical bonds include hydrogen bonds, covalent bonds, and ionic bonds. (09 Oct 1997) |
| phosphodiester bond | <chemistry> Not a precise term. Refers to any molecule in which two parts are joined through a phosphate group. Examples are found in RNA, DNA, phospholipids, cyclic nucleotides, nucleotide diphosphates and triphosphates. (18 Nov 1997) |
| pi bond | <chemistry> A bond formed from the overlap of two parallel p-orbitals. (09 Jan 1998) |
| coordinate covalent bond | A bond in which the two electrons shared by a pair of atoms belonged originally to only one of the atoms; often represented by a small arrow pointing toward the electron receiver; e.g., nitric acid, O(OH)N→O; phosphoric acid, (OH)3P→O. Synonym: coordinate covalent bond. (05 Mar 2000) |
| covalent bond | A bond between two or more atoms that is provided by electrons that travel between the atoms' nuclei, holding them together but keeping them a stable distance apart. (09 Oct 1997) |
| heteropolar bond | Bond between atoms or groups carrying opposite charges (or, in some cases, partial charges). Synonym: heteropolar bond, salt bridge. (05 Mar 2000) |
| semipolar bond | A bond in which the two electrons shared by a pair of atoms belonged originally to only one of the atoms; often represented by a small arrow pointing toward the electron receiver; e.g., nitric acid, O(OH)N→O; phosphoric acid, (OH)3P→O. Synonym: coordinate covalent bond. (05 Mar 2000) |
| hydrogen bond | <chemistry> A weak electrostatic link between an electronegative atom (such asoxygen) and a hydrogen atom which is linked covalently to anotherelectronegative atom, hydrogen bonding is what makes water stick toitself. (09 Oct 1997) |
| hydrophobic bond | See: hydrophobic interaction. (05 Mar 2000) |
| sigma bond | <chemistry> A bond formed from the overlap of either two s-orbitals or two hybrid orbitals such as sp3 or sp2 orbitals. (09 Jan 1998) |
| single bond | A covalent bond resulting from the sharing of one pair of electrons; e.g., H3C-CH3 (ethane). (05 Mar 2000) |