| apyrimidinic site | <molecular biology> A site on DNA where a base is missing, in this case a pyrimidine (either cytosine or thymine), but the phosphodiester backbone is still intact. Compare: apurinic site. (09 Oct 1997) |
|---|---|
| ATT site | <molecular biology> A site on the chromosome of the bacteria E. Coli where the lambda bacteriophage can insert its genome (all of its DNA) so that it can lie dormant and have its DNA reproduced whenever the bacterium reproduces for as long as the bacterium remains healthy (that is, so that it becomes lysogenic). (09 Oct 1997) |
| gaylus-site | <chemical> A yellowish white, translucent mineral, consisting of the carbonates of lime and soda, with water. Origin: Named after Gay-Lussac, the French chemist. (20 Mar 1998) |
| receptor site | Point of attachment of viruses, hormones, or other activators to cell membranes. (05 Mar 2000) |
| catalytic site | <chemistry> The site on an enzyme where the substrate or substrates (the reactants of a chemical or biochemical reaction) attach in order to convert to the product or products of the reaction, at a much higher speed than the substrate would need to convert to the product alone. (16 Mar 1998) |
| replication site | The in vivo site on DNA of DNA replication. (05 Mar 2000) |
| restriction enzyme cutting site | <molecular biology> A specific nucleotide sequence of DNA at which a particular restriction enzyme cuts the DNA. Some sites occur frequently in DNA (for example, every several hundred basepairs), others much less frequently (rare-cutter, for example, every 10,000 base pairs). (10 Mar 1998) |
| restriction site | A sequence in DNA that can be recognised and cut by a specific restriction enzyme. (12 Dec 1998) |
| restriction-site polymorphism | DNA polymorphism in which the sequence of one form of the polymorphism contains a recognition site for a particular endonuclease, but the sequence of the other form lacks such a site. (05 Mar 2000) |
| chi site | <molecular biology> Short, active sequences of DNA which strongly encourages crossing over of chromosomes to occur at that site. These sites become chiasmata more often than other sites. (05 Jan 1998) |
| ribosome binding site | The region of a messenger RNA molecule that binds the ribosome to initiate translation. (09 Oct 1997) |
| cleavage site | A sequence in DNA that can be recognised and cut by a specific restriction enzyme. (12 Dec 1998) |
| combining site | <biochemistry, immunology> Any region of a molecule that binds or reacts with a given compound. Especially of the region of immunoglobulin that combines with the determinant of an appropriate antigen. (09 Jan 1998) |
| placental site trophoblastic tumour | A tumour usually arising in the uterus of parous women during reproductive years. Histologically, the tumour consists of a predominance of intermediate trophoblastic cells with fibrinoid material and vascular invasion. (05 Mar 2000) |
| Con A binding site | <biochemistry> A common misuse of the term receptor. Con A binds to the mannose residues of many different glycoproteins and glycolipids and the binding is therefore not to a specific site. It could be argued that the receptor is the Con A and cells have Con A ligands on their surfaces: certainly this would be less confusing. (05 Jan 1998) |