| OCG | omnicardiogram; oral cholecystogram |
|---|---|
| OCH | oral contraceptive hormone |
| OCM | oral contraceptive medication |
| OCS | occipital condyle syndrome; Ondine's curse syndrome; open canalicular system; oral contraceptive ste... |
| OCT | object classification test; optimal cutting temperature; oral contraceptive therapy; ornithine carba... |
| pentose phosphate cycle | <biochemistry> A pathway of hexose oxidation in which glucose-6-phosphate undergoes two successive oxidations by NADP, the final one being an oxidative decarboxylation to form a pentose phosphate. Diverges from this when glucose-6-phosphate is oxidized to ribose 5 phosphate by the enzyme glucose-6 phosphate dehydrogenase. This step reduces NADP to NADPH, generating a source of reducing power in cells for use in reductive biosyntheses. In plants, part of the pathway functions in the formation of hexoses from carbon dioxide in photosynthesis. Also important as source of pentoses, for example for nucleic acid biosynthesis. This pathway is the main metabolic pathway in neutrophils, congenital deficiency in the pathway produces sensitivity to infection. Alternative metabolic route to Embden Meyerhof pathway for breakdown of glucose. (18 Nov 1997) |
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| pentose phosphate pathway | <biochemistry> A pathway of hexose oxidation in which glucose-6-phosphate undergoes two successive oxidations by NADP, the final one being an oxidative decarboxylation to form a pentose phosphate. Diverges from this when glucose-6-phosphate is oxidized to ribose 5 phosphate by the enzyme glucose-6 phosphate dehydrogenase. This step reduces NADP to NADPH, generating a source of reducing power in cells for use in reductive biosyntheses. In plants, part of the pathway functions in the formation of hexoses from carbon dioxide in photosynthesis. Also important as source of pentoses, for example for nucleic acid biosynthesis. This pathway is the main metabolic pathway in neutrophils, congenital deficiency in the pathway produces sensitivity to infection. Alternative metabolic route to Embden Meyerhof pathway for breakdown of glucose. (18 Nov 1997) |
| retinyl phosphate | The phosphoester of all-trans retinol; essential for the biosynthesis of certain glycoproteins needed for growth regulation and for mucous secretion. (05 Mar 2000) |
| riboflavin 5'-phosphate | <biochemistry> This biomolecule serves as a coenzyme for some enzymes that catalyse oxidation-reduction reactions. (09 Oct 1997) |
| ribose-5-phosphate | Ribose phosphorylated on carbon-5; an intermediate in the pentose phosphate pathway. (05 Mar 2000) |
| ribose-5-phosphate isomerase | <enzyme> An enzyme catalyzing interconversion of d-ribose 5-phosphate and d-ribulose 5-phosphate; of importance in ribose metabolism and in the pentose phosphate pathway. Synonym: phosphopentose isomerase, phosphoriboisomerase. (05 Mar 2000) |
| ribose-phosphate pyrophosphokinase | <enzyme> An enzyme that catalyses the formation of phosphoribosyl pyrophosphate from ATP and ribose-5-phosphate. Chemical name: ATP:ribose-5-phosphate pyrophosphotransferase Registry number: EC 2.7.6.1 (12 Dec 1998) |
| guaiacol phosphate | Phosphoric guaiacyl ether, a white crystalline powder, insoluble in water; used as an intestinal antiseptic and in fever. (05 Mar 2000) |
| RNA 3'-terminal phosphate cyclase | <enzyme> ATP dependent; forms 2',3' terminal cyclic phosphate on RNA which is then the substrate for RNA ligase of hela cells Registry number: EC 6.5.- Synonym: RNA tph cyclase (26 Jun 1999) |
| choline-phosphate cytidylyltransferase | <enzyme> An enzyme that catalyses the transfer of cytidylate (CMP) to choline phosphate to form CDPcholine. It is the rate-limiting enzyme in the choline pathway for the biosynthesis of phosphatidylcholine. Its activity is increased by glucocorticoids. Registry number: EC 2.7.7.15 (12 Dec 1998) |
| chromic phosphate P 32 colloidal suspension | A pure beta-emitting colloidal, nonabsorbable radiopharmaceutical administered into body cavities such as the pleural or peritoneal spaces to control malignant effusions. See: sodium phosphate P 32. (05 Mar 2000) |
| phosphate | <chemistry> A salt of phosphoric acid. Source: Websters Dictionary (01 Mar 1998) |
| phosphate acetyltransferase | <enzyme> An enzyme that catalyses the synthesis of acetylphosphate from acetyl-CoA and inorganic phosphate. Acetylphosphate serves as a high-energy phosphate compound. Chemical name: Acetyl-CoA:orthophosphate acetyltransferase Registry number: EC 2.3.1.8 (12 Dec 1998) |
| phosphate diabetes | Excessive secretion of phosphate in the urine due to a defect in tubular reabsorption; usually part of a more generalised abnormality, such as Fanconi syndrome. (05 Mar 2000) |
| phosphate group | <chemistry> A phosphate group on a larger molecule, where the phosphorus is single bonded to each of the four oxygens, and the other bond of one of the oxygens is attached to the rest of the molecule. This means that the entire group has a net negative charge of -3 (from the free second bonds on the oxygen atoms which are only bonded to the phosphorus atom). Often hydrogen atoms will be attached to the oxygens and sometimes double bonds between the phosphorus and an oxygen are present. (31 Dec 1997) |