| ADE | acute disseminated encephalitis; adverse drug event; antibody-dependent enhancement; apparent digest... |
|---|---|
| AE | above-elbow [amputation]; acrodermatitis enteropathica; activation energy; adult erythrocyte; advers... |
| AEC | ankyloblepharon, ectodermal defects, and cleft lip [syndrome]; at earliest convenience; Atomic Energ... |
| AEE | atomic energy establishment |
| AERE | Atomic Energy Research Establishment |
energetics
| 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) |
| noncovalent bond | Bond in which electrons are not shared between atoms; e.g., electrostatic bond, hydrogen bond. (05 Mar 2000) |
| sulfur-sulfur bond isomerases | <enzyme> Enzymes that catalyze the transposition of a sulfur-sulfur bond. Registry number: EC 5.3.4 (12 Dec 1998) |
| disulfide bond | A single bond between two sulfurs; specifically, the -S-S- link binding two peptide chains (or different parts of one peptide chain); also occurs as part of the molecule of the amino acid, cystine, and is important as a structural determinant in many protein molecules, notably keratin, insulin, and oxytocin. A symmetric disulfide is R-S-S-R; R'-S-S-R is a mixed disulfide. (05 Mar 2000) |
| disulphide bond | <chemistry, molecular biology> The S S linkage. A linkage formed between the SH groups of two cysteine moieties either within or between peptide chains. Each cysteine then becomes a half cystine residue. S S linkages stabilise, but do not determine, secondary structure in proteins. They are easily disrupted by SH groups in an exchange reaction and are not present in cytosolic proteins (cytosol has a high concentration of glutathione that has a free SH residue). (18 Nov 1997) |
| double bond | <chemistry> A covalent bond resulting from the sharing of two pairs of electrons; e.g., H2C==CH2 (ethylene). (05 Mar 2000) |