| RNA, transfer, met | A transfer RNA which is specific for carrying methionine to sites on the ribosomes in preparation for protein elongation. Initiation of protein synthesis uses trna(f)met in prokaryotic cells and trna(I)met in eukaryotic cells. (12 Dec 1998) |
|---|---|
| RNA, transfer, phe | A transfer RNA which is specific for carrying phenylalanine to sites on the ribosomes in preparation for protein synthesis. (12 Dec 1998) |
| RNA, transfer, pro | A transfer RNA which is specific for carrying proline to sites on the ribosomes in preparation for protein synthesis. (12 Dec 1998) |
| RNA, transfer, ser | A transfer RNA which is specific for carrying serine to sites on the ribosomes in preparation for protein synthesis. (12 Dec 1998) |
| RNA, transfer, thr | A transfer RNA which is specific for carrying threonine to sites on the ribosomes in preparation for protein synthesis. (12 Dec 1998) |
| RNA, transfer, trp | A transfer RNA which is specific for carrying tryptophan to sites on the ribosomes in preparation for protein synthesis. (12 Dec 1998) |
| RNA, transfer, tyr | A transfer RNA which is specific for carrying tyrosine to sites on the ribosomes in preparation for protein synthesis. (12 Dec 1998) |
| RNA, transfer, val | A transfer RNA which is specific for carrying valine to sites on the ribosomes in preparation for protein synthesis. (12 Dec 1998) |
| transfer RNA | <molecular biology> A nucleic acid found in all living cells. Plays a role in transferring information from DNA to the protein-forming system of the cell. (16 Dec 1997) |
| Amine Precursor Uptake and Decarboxylation | <pharmacology, physiology> Paracrine cells of which argentaffin cells are an example. Usage of the term APUD is neither helpful nor memorable. Acronym: APUD (11 Nov 1997) |
| amyloid beta-protein precursor | A precursor to the amyloid-beta protein (beta/a4). Alterations in the expression of the amyloid beta-protein precursor (abpp) gene, located on chromosome 21, plays a role in the development of the neuropathology common to both alzheimer disease and down syndrome. Abpp is associated with the extensive extracellular matrix secreted by neuronal cells. Upon cleavage, this precursor produces three proteins of varying amino acid lengths: 695, 751, and 770. The beta/a4 (695 amino acids) or beta-amyloid protein is the principal component of the extracellular amyloid in senile plaques found in alzheimer disease, down syndrome and, to a limited extent, in normal aging. (12 Dec 1998) |
| amyloid precursor protein | <protein> Individuals with Alzheimer's disease are characterised by extensive accumulation of amyloid in the brain, referred to as senile plaques. These consist of a core of amyloid fibrils surrounded by dystrophic neurites. The principal component of the amyloid fibrils is B/A4, a peptide derived from the larger APP. The specific role of amyloid protein is unclear but it is thought that amyloid deposits may cause neurons to degenerate. Amyloid deposits also occur in brains of older Down's Syndrome patients. (04 May 1997) |
| angiotensin precursor | angiotensin |
| precursor | Something that precedes. 1. <biochemistry> In biological processes, a substance from which another, usually more active or mature substance is formed. 2. In clinical medicine, a sign or symptom that heralds another. Origin: L. Praecursor = a forerunner (18 Nov 1997) |
| enzyme precursor | <biochemistry> Inactive precursors that can be converted to active enzymes. Enzyme precursors containing extra-long polypeptide chains that block activity are activated by acid or enzymatic hydrolysis to remove the inhibiting portion. (12 Dec 1998) |