| 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) |
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| 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) |
| stereo- | <prefix> A combining form meaning solid, hard, firm, as in stereochemistry, stereography. Origin: Gr. Stereos solid. See Stare to gaze. (29 Oct 1998) |
| stereo-orthopter | A type of stereoscope used in visual training. Origin: stereo-+ G. Orthos, straight, + optikos, optical (05 Mar 2000) |
| active carbon dioxide | Activated carbon dioxide, a complex of N-carboxybiotin (biotin + CO2) and an enzyme; the form in which carbon dioxide is added to other molecules in carboxylations; e.g., to methylcrotonyl-CoA to form beta-methylglutaconyl in the catabolism of leucine, and to acetyl-CoA to form malonyl-CoA. See: acetyl-CoA carboxylase. (05 Mar 2000) |
| anomeric carbon | The reducing carbon of a sugar; C-1 of an aldose, C-2 of a 2-ketose. (05 Mar 2000) |
| arteriovenous carbon dioxide difference | <physiology> The difference in carbon dioxide content (in ml per 100 ml blood) between arterial and venous blood. (05 Mar 2000) |
| carbon | <chemistry, element> Sixth element (Z=6) in the periodic table, has 6 protons, often described as the basis of life on earth because of its chemical properties, has potential for use with silicon as a low-activation structural material for fusion reactors, in the form silicon carbide. Carbon tiles are often used in plasma-facing components because its low Z makes carbon a relatively nice impurity. It is also useful as a neutron moderator. See: low-activation materials, plasma-facing components. Abbreviation: C (13 Nov 1997) |
| 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 bisulfide | <chemical> Carbon disulfide (cs2). A colourless, flammable, poisonous liquid, cs2. It is used as a solvent, and is a counterirritant and has local anaesthetic properties but is not used as such. It is highly toxic with pronounced CNS, haematologic, and dermatologic effects. Chemical name: Carbon disulfide (12 Dec 1998) |
| carbon compounds, inorganic | Inorganic compounds that contain carbon as an integral part of the molecule but are not derived from hydrocarbons. (12 Dec 1998) |