| tandem repeat sequence | <molecular biology> Multiple copies of the same base sequence on a chromosome, used as a marker in physical mapping. (09 Oct 1997) |
|---|---|
| termination sequence | <molecular biology> The three codons, UAA known as ochre, UAG as amber and UGA as opal, that do not code for an amino acid but act as signals for the termination of protein synthesis. They are not represented by any tRNA and termination is catalysed by protein release factors. There are two release factors in E. Coli, RF1 recognises UAA and UAG, RF2 recognises UAA and UGA. Eukaryotes have a single GTP requiring factor, eRF. See: ochre suppressor, amber suppressor. (13 Jan 1998) |
| enhancer sequence | <molecular biology> A nucleotide sequence, located as many as several thousand base pairs away in either direction from the target gene, which enhances transcription of that gene. (14 Nov 1997) |
| evolutionarily conserved sequence | A base sequence in a DNA molecule (or an amino acid sequence in a protein) that has remained essentially unchanged throughout evolution. (12 Dec 1998) |
| Expressed Sequence Tag | <molecular biology> Expressed sequence tags are sequence tagged sites derived from cDNAs. See: sequence tagged site. Acronym: EST (06 Aug 1998) |
| flanking sequence | <molecular biology> Short DNA sequences bordering a transcription unit. Often these do not code for proteins. (18 Nov 1997) |
| leader sequence | <molecular biology> In the regulation of gene expression for enzymes concerned with amino acid synthesis in prokaryotes, the leader sequence codes for the leader peptide that contains several residues of the amino acid being regulated. Transcription is closely linked to translation and if translation is retarded by limited supply of amino acyl tRNA for the specific amino acid, the mode of transcription of the leader sequence permits full transcription of the operon genes, otherwise complete transcription of the leader sequence prematurely terminates transcription of the operon. (18 Nov 1997) |
| abdominal pulse | The soft, compressible aortic pulse occurring in certain abdominal disorders. Synonym: pulsus abdominalis. (05 Mar 2000) |
| alternating pulse | Mechanical alternation, a pulse regular in time but with alternate beats stronger and weaker, often detectable only with the sphygmomanometer and usually indicating serious myocardial disease. Synonym: pulsus alternans. (05 Mar 2000) |
| amplitude of pulse | See: average pulse magnitude, peak magnitude. (05 Mar 2000) |
| anacrotic pulse | A pulse wave showing one or more notches or indentations on its rising limb that are sometimes detectable by palpation. Synonym: pulsus anadicrotus. (05 Mar 2000) |
| asynchronous pulse generator | A generator in which the rate of discharge is independent of the natural activity of the heart. Synonym: fixed rate pulse generator. (05 Mar 2000) |
| atrial synchronous pulse generator | A ventricular stimulating pulse whose rate of discharge is directly determined by the atrial rate. Synonym: atrial triggered pulse generator. (05 Mar 2000) |
| atrial triggered pulse generator | A ventricular stimulating pulse whose rate of discharge is directly determined by the atrial rate. Synonym: atrial triggered pulse generator. (05 Mar 2000) |
| average pulse magnitude | <physics> The amplitude of pulse averaged throughout its duration; identical with peak amplitude for a square wave or pulse without droop. (05 Mar 2000) |