| ascorbate | A salt or ester of ascorbic acid. Ascorbate oxidase, a copper-containing enzyme that catalyses the oxidation of l-ascorbic acid with O2 to l-dehydroascorbic acid. Some forms of ascorbate oxidase use NADP+ as well. Used as an antitumour enzyme. Synonym: ascorbase. (05 Mar 2000) |
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| ascorbate oxidase | <enzyme> An enzyme that converts ascorbic acid to dehydroascorbic acid. Chemical name: L-Ascorbate:oxygen oxidoreductase Registry number: EC 1.10.3.3 (12 Dec 1998) |
| ascorbate peroxidase | <enzyme> Occurs in the stroma as a soluble form (sap28) and also in the thylakoids as membrane-bound form (sap22) in angiosperm chloroplasts Registry number: EC 1.11.1.11 Synonym: ascorbic acid peroxidase, l-ascorbic acid peroxidase, stromal ascorbate peroxidase, thylakoid-bound ascorbate peroxidase (26 Jun 1999) |
| ascorbate-cyanide test | A test for glucose-6-phosphate-deficient red blood cells; blood is incubated with sodium cyanide and ascorbate; the hydrogen peroxide generated is free to oxidise haemoglobin to methemoglobin, since cyanide inhibits catalase; a brown colour is produced more rapidly in glucose 6-phosphate-deficient cells. (05 Mar 2000) |
| ascorbic acid | <biochemistry> A requisite in the diet of man and guinea pigs. May act as a reducing agent in enzymic reactions, particularly those catalysed by hydroxylases. Synonym: Vitamin C. (18 Nov 1997) |
| ascorbic acid deficiency | A condition due to a dietary deficiency of ascorbic acid (vitamin c), characterised by malaise, lethargy, and weakness. As the disease progresses, joints, muscles, and subcutaneous tissues may become the sites of haemorrhage. Ascorbic acid deficiency frequently develops into scurvy in young children fed unsupplemented cow's milk exclusively during their first year. It develops also commonly in chronic alcoholism. (cecil textbook of medicine, 19th ed, p1177) (12 Dec 1998) |
| ascorbyl palmitate | L-Ascorbic acid-6-palmitate;used as a preservative in pharmaceutical preparations. (05 Mar 2000) |
| ascospore | <botany> One of the spores contained in the asci of lichens and fungi. Origin: Ascus + spore. Source: Websters Dictionary (01 Mar 1998) |
| ascus | <fungus> Elongated spore case containing 4 or 8 haploid sexual ascospores of ascomycete fungi (which include yeasts). (18 Nov 1997) |