| carbon-oxygen ligases | <enzyme> Enzymes that catalyze the joining of two molecules by the formation of a carbon-oxygen bond. Registry number: EC 6.1 (12 Dec 1998) |
|---|---|
| carbon-oxygen lyases | <enzyme> Enzymes that catalyze the cleavage of a carbon-oxygen bond by means other than hydrolysis or oxidation. Registry number: EC 4.2 (12 Dec 1998) |
| carbon-phosphorus lyase | <enzyme> Found in bacteria which utilise alkyl and phenylphosphonic acids Registry number: EC 4.99.- Synonym: c-p lyase, carbon-phosphorus cleavage enzyme (26 Jun 1999) |
| carbon radioisotopes | Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes. (12 Dec 1998) |
| carbon source | Any carbon-containing organic molecule (carbohydrate, aminoacid) that an organism can use to produce energy in the form of ATP. (09 Oct 1997) |
| carbon-sulfur ligases | <enzyme> Enzymes that catalyze the joining of two molecules by the formation of a carbon-sulfur bond. Registry number: EC 6.2 (12 Dec 1998) |
| carbon-sulfur lyases | <enzyme> Enzymes that catalyze the cleavage of a carbon-sulfur bond by means other than hydrolysis or oxidation. Registry number: EC 4.4 (12 Dec 1998) |
| carbon tetrachloride | <chemical> Tetrachloromethane. A solvent for oils, fats, lacquers, varnishes, rubber waxes, and resins, and a starting material in the manufacturing of organic compounds. Poisoning by inhalation, ingestion or skin absorption is possible and may be fatal. Chemical name: Methane, tetrachloro- (12 Dec 1998) |
| quaternary carbon atom | An atom of carbon to which four other carbon atom's are attached. (05 Mar 2000) |
| one-carbon fragment | The formyl group or the methyl group that takes part in transformylation or transmethylation reactions; by means of these reactions, a group containing a single carbon atom is added to a compound being biosynthesised, adding a methyl group (as in thymidine formation), adding a hydroxymethyl group (as in serine biosynthesis), or closing a ring (as in purine formation). (05 Mar 2000) |
| one-carbon group transferases | <enzyme> A subclass of transferases that transfer chemical groups containing a single carbon. These include the methyltransferases, the hydroxymethyl and formyl transferases, the carboxyl and carbamoyl transferases, and the amidinotransferases. Registry number: EC 2.1 (12 Dec 1998) |
| two-carbon fragment | The acetyl group (CH3CO-) that takes part in transacetylation reactions with coenzyme A as carrier; commonly referred to as acetate or acetic acid, from which it is derived. (05 Mar 2000) |
| abscopal effect | A reaction produced following irradiation but occurring outside the zone of actual radiation absorption. (05 Mar 2000) |
| additive effect | <biochemistry, chemistry> An additive effect is the overall biological effect two chemicals acting together and which is the simple sum of the effects of the chemicals acting independently. Compare: antagonism. (15 Jan 1998) |
| adverse effect | This is an abnormal or harmful effect to an organism caused by exposure to a chemical. It is indicated by some result such as death, a change in food or water consumption, altered body and organ weights, altered enzyme levels, or visible illness. An effect may be classed as adverse if it causes functional or anatomical damage, causes irreversible change in the homeostasis of the organism, or increases the susceptibility of the organism to other chemical or biological stress. A non-adverse effect will usually be reversed when the organism is no longer being exposed to the chemical. (09 Oct 1997) |