| nonpolar compound | A compound composed of molecules that possess a symmetrical distribution of charge, so that no positive or negative poles exist, and that are not ionizable in solution; e.g., hydrocarbons. See: organic compound. (05 Mar 2000) |
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| surface active compound | <biochemistry> Usually, in biological systems, means a detergent like molecule that is amphipathic and that will bind to the plasma membrane or to a surface with which cells come in contact, altering its properties from hydrophobic to hydrophilic or vice versa. (18 Nov 1997) |
| impression compound | A thermoplastic material usually composed of gum damar and prepared chalk, used especially for making dental impressions. Synonym: impression compound, modeling composition, modeling compound. (05 Mar 2000) |
| inclusion compound | The mechanical trapping of small molecules within spaces between other molecules; e.g., the inclusion of iodine molecules by starch molecules to form the well-known red-to-black "addition compound" (05 Mar 2000) |
| inorganic compound | A compound in which the atoms or radicals consist of elements other than carbon and are typically held together by electrostatic forces rather than by covalent bonds; often are capable of dissociation into ions in polar solvents (e.g., H2O). Compare: organic compound. (05 Mar 2000) |
| isocyclic compound | Any compound in which the constituent atoms, or any part of them, form a ring. Used mainly in organic chemistry where: 1) numerous compound's contain rings of carbon atoms (carbocyclic compound's) or carbon atoms plus one or more atoms of other types (heterocyclic compound's), usually nitrogen, oxygen, or sulfur; 2) where the atoms in the ring are all of the same element (homocyclic or isocyclic compound); 3) where the ring is saturated or contains nonconjugated double bonds (alicyclic compound), the compound is similar in properties to the corresponding acyclic compound (e.g., cyclohexane resembles hexane); 4) where the ring contains conjugated double bonds in a closed loop in which there are 4n + 2 (where n is an integer) delocalised π electrons (Huckel's rule) (aromatic compound; e.g., benzene, pyridine), it is more stable than the corresponding saturated ring and exhibits unusual chemical properties characteristic of itself and not of other types of rings or of acyclic compound's. These aromatic compounds have the ability to sustain an induced ring current. Synonym: closed chain compound, ring compound. (05 Mar 2000) |
| organic compound | <chemistry> A compound containing carbon. (11 Jan 1998) |
| lens, compound | <microscopy> A lens composed of two or more separate pieces of glass or other optical maternal. These component pieces or elements may or may not be cemented together. A common form of compound lens is a two-element objective, one element being a converging lens of crown glass and the other a diverging lens of flint glass. The combination of suitable glasses or other optical materials (plastics, minerals) properly ground and polished reduces aberrations normally present in a single lens. (05 Aug 1998) |
| A chain | A polypeptide component of insulin containing 21 amino acyl residues, beginning with a glycyl residue (NH2-terminus); insulin is formed by the linkage of an A chain to a B chain by two disulfide bonds; the amino-acid composition of the A chain is a function of species. Synonym: glycyl chain. In general, one of the polypeptides in a multiprotein complex. (05 Mar 2000) |
| alpha chain disease | A vague or indefinite term; could be used for alpha-heavy-chain disease (a lymphoplasma cell proliferative disease usually seen in Mediterranean men, characterised by intestinal involvement with steatorrhoea, often progressive with fatal outcome) or a thalassaemia (a genetic abnormality in the alpha globin chain of haemoglobin). (05 Mar 2000) |
| amino acids, branched-chain | Amino acids which have a branched carbon chain. (12 Dec 1998) |
| B chain | A polypeptide component of insulin containing 30 amino acyl residues, beginning with a phenylalanyl residue (NH2-terminus); insulin is formed by the linkage of a B chain to an A chain by two disulfide bonds; the amino-acid composition of the B chain is a function of species. Synonym: phenylalanyl chain. (05 Mar 2000) |
| behaviour chain | Related behaviours in a series in which each response serves as a stimulus for the next response. (05 Mar 2000) |
| branched chain acyl-CoA oxidase | <enzyme> Enzyme from human liver peroxisomes acts on both 2-methyl branched fatty acyl- and bile acid-CoA intermediates, unlike rat liver peroxisomes which have separate enzymes for branched chain fatty acids (pristanoyl-CoA) and bile acid-CoA; involved in beta-oxidation of fatty acids and bil Registry number: EC 1.3.3.- Synonym: 2-methyl-branched chain acyl-CoA oxidase, hbrcacox (26 Jun 1999) |
| branched-chain fatty-acid-kinase | <enzyme> From anaerobic spirochete ma-2 Registry number: EC 2.7.2.14 Synonym: isovalerate kinase, 2-methylbutyrate kinase, isobutyrate kinase (26 Jun 1999) |