| 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) |
| alveolar point | The most anterior point on the maxillary alveolar process in the midline. Synonym: alveolar point, prostheon. Origin: G. Ntr. Of prosthios, foremost (05 Mar 2000) |
| anterior focal point | The point where parallel rays from the retina are focused. (05 Mar 2000) |
| apophysial point | The centre of the root of the anterior nasal spine. Synonym: apophysary point, apophysial point, spinal point. (05 Mar 2000) |
| arrow point tracing | A tracing of mandibular movements made by means of a device attached to the opposing arches; its shape resembles that of an arrowhead or a Gothic arch, and when the instrument's marking point is at the apex of the arch, the jaws are considered to be in centric relation. Synonym: arrow point tracing, Gothic arch tracing, Gothic arch, stylus tracing. (05 Mar 2000) |
| auricular point | A craniometric point at the centre of the opening of the external acoustic meatus; or, in certain cases, the middle of the upper edge of this opening. Synonym: auricular point. Origin: L. Auricularis, pertaining to the ear (05 Mar 2000) |
| axial point | One of two point's in a compound optical system so related that a ray directed toward the first point will appear to have passed through the second point parallel to its original direction. Synonym: axial point. (05 Mar 2000) |
| boiling point | This is the temperature at which the vapor pressure of a given liquid reaches atmospheric pressure (and thus starts to boil). (09 Oct 1997) |
| boiling point elevation | This is the phenomenon of increasing the temperature at which a liquid boils by dissolving another substance in the liquid (for example: you can raise the temperature at which water boils by adding salt to it). (09 Oct 1997) |
| Cannon's point | The location in the mid-transverse colon at which innervation by superior and inferior mesenteric plexuses overlap at the junction of the primitive midgut and hindgut, frequently resulting in narrowing evident on barium enema. See: Cannon's ring. Synonym: Cannon's ring. (05 Mar 2000) |