| 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 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) |
| carbon-11 | A cyclotron-produced, positron-emitting radioisotope of carbon with a half-life of 20.3 minutes; used in positron-emitting tomography. (05 Mar 2000) |
| carbon-12 | The standard of atomic mass, 98.90% of natural carbon. (05 Mar 2000) |
| carbon-13 | A stable natural isotope, 1.1% of natural carbon. (05 Mar 2000) |
| carbon-14 | A beta-emitter with a half-life of 5715 years, widely used as a tracer in studying various aspects of metabolism; naturally occurring 14C, arising from cosmic ray bombardment, is used to date relics containing natural carbonaceous materials. (05 Mar 2000) |
| 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) |
| carbon-carbon ligases | <enzyme> Enzymes that catalyze the joining of two molecules by the formation of a carbon-carbon bond. These are the carboxylating enzymes and are mostly biotinyl-proteins. Registry number: EC 6.4 (12 Dec 1998) |
| carbon-carbon lyases | <enzyme> Enzymes that catalyze the cleavage of a carbon-carbon bond by means other than hydrolysis or oxidation. This subclass contains the decarboxylases, the aldehyde-lyases, and the oxo-acid-lyases. Registry number: EC 4.1 (12 Dec 1998) |
| carbon-nitrogen ligases | <enzyme> Enzymes that catalyze the joining of two molecules by the formation of a carbon-nitrogen bond. Registry number: EC 6.3 (12 Dec 1998) |
| carbon-nitrogen ligases with glutamine as amide-n-donor | <enzyme> Enzymes that catalyze the joining of glutamine-derived ammonia and another molecule. The linkage is in the form of a carbon-nitrogen bond. Registry number: EC 6.3.5 (12 Dec 1998) |
| carbon-nitrogen lyases | <enzyme> Enzymes that catalyze the cleavage of a carbon-nitrogen bond by means other than hydrolysis or oxidation. Subclasses are the ammonia-lyases, the amidine-lyases, the amine-lyases, and other carbon-nitrogen lyases. Registry number: EC 4.3 (12 Dec 1998) |
| 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) |