| definitive callus | The callus which has become converted into osseous tissue. Synonym: permanent callus. (05 Mar 2000) |
|---|---|
| definitive erythroblast | <haematology, pathology> Embryonic erythroblast found in the liver, smaller than primitive erythroblasts, they lose their nucleus at the end of the maturation cycle and produce erythrocytes with adult haemoglobin. (18 Nov 1997) |
| definitive host | <epidemiology> The host in which a parasite reproduces sexually. (05 Dec 1998) |
| definitive lysosomes | Lysosome's in which lysis takes place, owing to the activity of hydrolytic enzymes; they are believed to eventually become residual bodies. Synonym: definitive lysosomes, digestive vacuole. (05 Mar 2000) |
| definitive method | An analytical procedure for the measurement of a specified analyte in a specified material which is known to give essentially the true value for the concentration of the analyte. (05 Mar 2000) |
| definitive prosthesis | A dental prosthesis to be used over a prescribed period of time. (05 Mar 2000) |
| acceptor site | The ribosomal binding site for the aminoacyl-tRNA during protein synthesis. (05 Mar 2000) |
| acceptor splicing site | Boundary between the right end of an intron and the left end of the adjacent exon. Synonym: acceptor splicing site. (05 Mar 2000) |
| active site | <chemistry> A specific region of an enzyme where a substrate binds and catalysis takes place (binding site). (06 May 1997) |
| allosteric site | A specific site on a multi-subunit enzyme or other protein that is not the substrate binding site, but that when reversibly bound by an effector, induces a conformational change in the protein, altering its catalytic or binding properties. (12 Dec 1998) |
| amidation site | <molecular biology> A C terminus consensus sequence, required for C terminus amidation of peptides. Consensus is glycine, followed by 2 basic amino acids (arg or lys). (18 Nov 1997) |
| antibody combining site | <immunology> In immune network theory, an idiotope, an antigenic site of an antibody that is responsible for that antibody binding to an antigenic determinant (epitope). Also used of the site on a ligand molecule to which a cell surface receptor binds. (18 Nov 1997) |
| antigen-binding site | <immunology> In immune network theory, an idiotope, an antigenic site of an antibody that is responsible for that antibody binding to an antigenic determinant (epitope). Also used of the site on a ligand molecule to which a cell surface receptor binds. (18 Nov 1997) |
| antigen-combining site | See: paratope. (05 Mar 2000) |
| apurinic site | <molecular biology> Sites in DNA from which purines have been lost by cleavage of the deoxy ribose N glycosidic linkage. (18 Nov 1997) |