| threonine acetaldehyde-lyase | <enzyme> Catalyses conversion of threonine to glycine and acetaldehyde; do not confuse with threonine aldolase (EC 2.1.2.1) Registry number: EC 4.1.2.5 Synonym: l-threonine acetaldehyde-lyase, d-threonine acetaldehyde-lyase, threonine aldolase (lyase) (26 Jun 1999) |
|---|---|
| threonine deaminase | <enzyme> A pyridoxal-phosphate protein that catalyses the deamination of threonine to 2-ketobutyrate and ammonia. The role of this enzyme can be biosynthetic or biodegradative. In the former role it supplies 2-ketobutyrate required for isoleucine biosynthesis, while in the latter it is only involved in the breakdown of threonine to supply energy. Chemical name: L-Threonine hydro-lyase (deaminating) Registry number: EC 4.2.1.16 (12 Dec 1998) |
| threonine dehydratase | <enzyme> A pyridoxal-phosphate protein that catalyses the deamination of threonine to 2-ketobutyrate and ammonia. The role of this enzyme can be biosynthetic or biodegradative. In the former role it supplies 2-ketobutyrate required for isoleucine biosynthesis, while in the latter it is only involved in the breakdown of threonine to supply energy. Chemical name: L-Threonine hydro-lyase (deaminating) Registry number: EC 4.2.1.16 (12 Dec 1998) |
| threonine permease | <chemical> Membrane-associated threonine permease encoded by tdcc gene of E coli Chemical name: permease, threonine Synonym: threonine-serine permease, tdcc gene product (26 Jun 1999) |
| threonine-trna ligase | <enzyme> An enzyme that activates threonine with its specific transfer RNA. Chemical name: L-Threonine:tRNA(Thr) ligase (AMP-forming) Registry number: EC 6.1.1.3 (12 Dec 1998) |
| threonyl tRNA synthetase kinase | <enzyme> From postribosomal supernatants of bom:nmri mouse liver; comigrates with threonyl trna synthetase during several purification steps Registry number: EC 2.7.1.- Synonym: thr trna synthetase kinase (26 Jun 1999) |
| threose | <biochemistry> A four carbon sugar in which the two central hydroxyl groups are in trans orientation (cis in erythrose). (18 Nov 1997) |
| threpsology | <study> The doctrine of nutrition; a treatise on nutrition. Origin: Gr. Nourishment. (04 Mar 1998) |
| thresher | 1. One who, or that which, thrashes grain; a thrashing machine. 2. <zoology> A large and voracious shark (Alopias vulpes), remarkable for the great length of the upper lobe of its tail, with which it beats, or thrashes, its prey. It is found both upon the American and the European coasts. Synonym: fox shark, sea ape, sea fox, slasher, swingle-tail, and thrasher shark. 3. <zoology> A name given to the brown thrush and other allied species. See Brown thrush. Sage thrasher. <zoology> The common killer of the Atlantic. Source: Websters Dictionary (01 Mar 1998) |
| thresher's lung | <chest medicine> Type III hypersensitivity response to Micropolyspora faeni, a thermophilic bacterium found in mouldy hay. (18 Nov 1997) |
| threshold | 1. The point at which a stimulus first produces a sensation. 2. The lower limit of perception of a stimulus. 3. The minimal stimulus that produces excitation of any structure; e.g., the minimal stimulus eliciting a motor response. Synonym: limen. Origin: A.S. Therxold (05 Mar 2000) |
| threshold body | Any material (e.g., glucose) that is excreted in the urine only when its plasma concentration exceeds a certain value, termed its threshold. Synonym: threshold body. (05 Mar 2000) |
| threshold differential | The smallest difference which can be discriminated between two stimuli or one which is barely above the threshold. (12 Dec 1998) |
| threshold limit value | The maximum concentration of a chemical recommended by the American Conference of Government Industrial Hygienists for repeated exposure without adverse health effects on workers. (05 Mar 2000) |
| threshold of consciousness | The lowest point at which a stimulus sensation can be perceived. (05 Mar 2000) |