| ammonia assimilation | The utilization of ammonia (or ammonium ions) in the net synthesis of nitrogen-containing molecules; e.g., glutamine synthetase. Synonym: ammonia fixation. (05 Mar 2000) |
|---|---|
| ammonia detoxication | The detoxication of ammonia and ammonium ion by the formation of ammonium salts, specific nitrogen-excretion products, or l-glutamine. (05 Mar 2000) |
| ammonia fixation | The utilization of ammonia (or ammonium ions) in the net synthesis of nitrogen-containing molecules; e.g., glutamine synthetase. Synonym: ammonia fixation. (05 Mar 2000) |
| ammonia-lyases | <enzyme> Enzymes that catalyze the formation of a c=c bond in a molecule by liberation of ammonia. Registry number: EC 4.3.1. (12 Dec 1998) |
| ammonia monooxygenase | <enzyme> Ammonia is oxidised to hydroxylamine by nitrifying bacterium, nitrosomonas europaea; also hydroxylates alkanes and arenes; converts alkenes to epoxides Registry number: EC 1.7.3.- Synonym: ammonia mono-oxygenase (26 Jun 1999) |
| ammonia rash | Colloquially referred to as diaper, ammonia, or napkin rash; dermatitis of thighs and buttocks resulting from exposure to urine and faeces in infants' diapers. Formerly attributed to ammonia formation; moisture, bacterial growth, and alkalinity may all induce lesions. Synonym: ammonia rash, diaper rash, Jacquet's erythema, napkin rash. (05 Mar 2000) |
| aspartate-ammonia ligase | <enzyme> An enzyme that catalyses the formation of asparagine from ammonia and aspartic acid, in the presence of ATP. Chemical name: L-Aspartate:ammonia ligase (AMP-forming) Registry number: EC 6.3.1.1 (12 Dec 1998) |
| aspartate ammonia-lyase | <enzyme> An enzyme that catalyses the conversion of aspartic acid to ammonia and fumaric acid in plants and some microorganisms. Chemical name: L-Aspartate ammonia-lyase Registry number: EC 4.3.1.1 (12 Dec 1998) |
| carbamoyl-phosphate synthase (ammonia) | <enzyme> An enzyme that catalyses the formation of carbamoyl phosphate from ATP, carbon dioxide, and ammonia. This enzyme is specific for arginine biosynthesis or the urea cycle. Chemical name: Carbon dioxide:ammonia ligase (ADP-forming, carbamate-phosphorylating) Registry number: EC 6.3.4.16 (12 Dec 1998) |
| glutamate-ammonia ligase | <enzyme> An enzyme that catalyses the conversion of ATP, l-glutamate, and nh3 to ADP, orthophosphate, and l-glutamine. It also acts more slowly on 4-methylene-l-glutamate. Chemical name: L-Glutamate:ammonia ligase (ADP-forming) Registry number: EC 6.3.1.2 (12 Dec 1998) |
| phenylalanine ammonia lyase | <enzyme> An enzyme that catalyses the deamination of l-phenylalanine to form trans-cinnamate and ammonia. It may also act on l-tyrosine. Since the enzyme deprives neoplastic tissue of phenylalanine, it has been used experimentally in the treatment of acute lymphoblastic leukaemia. The enzyme is obtained from many plants and is used as an enzymic marker for lignification and other developmental processes in plant cells. Pharmacological action: antineoplastic agent. Chemical name: L-Phenylalanine ammonia-lyase Registry number: EC 4.3.1.5 (12 Dec 1998) |
| histidine ammonia-lyase | <enzyme> An enzyme of the lyase class that catalyses the reaction of l-histidine to form urocanate and ammonia. The reaction is the initial step of histidine catabolism. Genetic deficiency of the enzyme, transmitted as an autosomal recessive trait, causes histidinaemia. Chemical name: L-Histidine ammonia-lyase Registry number: EC 4.3.1.3 (12 Dec 1998) |
| diaminopropionate ammonia-lyase | <enzyme> Used for the determination of diaminopropionic acid Registry number: EC 4.3.1.- (26 Jun 1999) |
| ethanolamine ammonia-lyase | <enzyme> An enzyme that catalyses the deamination of ethanolamine to acetaldehyde. Chemical name: Ethanolamine ammonia-lyase Registry number: EC 4.3.1.7 (12 Dec 1998) |
| L-tyrosine ammonia-lyase | <enzyme> Catalyses the conversion of tyrosine to trans-p-coumaric acid and ammonia Registry number: EC 4.3.1.- Synonym: tyrosine ammonia-lyase (26 Jun 1999) |