| MRF | Markov random field; medical record file; melanocyte-[stimulating hormone]-releasing factor; mesence... |
|---|---|
| NRC | National Research Council; National Response Center; normal retinal correspondence; not routine care... |
| RH | radiant heat; radiation hybrid; radiological health; reactive hyperemia; recurrent herpes; regulator... |
| CBG | capillary blood gases; coronary bypass graft; corticosteroid-binding globulin; cortisol-binding glob... |
| IBC | Institutional Biosafety Committee; iodine-binding capacity; iron-binding capacity; isobutyl cyanoacr... |
| noble element | A metal that cannot be oxidised by heat alone, nor readily dissolved by acid; e.g., gold, platinum. Synonym: noble element. (05 Mar 2000) |
|---|---|
| dyad symmetry element | Dyad symmetry element bound by serum response factor to control the expression of c fos. (18 Nov 1997) |
| Is element | Mobile nucleotide sequences that occur naturally in the genomes of bacterial populations. When inserted into bacterial DNA, they inactivate the gene concerned, when they are removed the gene regains its activity. Closely related to transposons and range in size from a few hundred to a few thousand bases, but are usually less than 1500 bases. (18 Nov 1997) |
| electronegative element | An element whose atoms have a tendency to accept electrons and form negative ions (e.g., oxygen, sulfur, chlorine, etc.). (05 Mar 2000) |
| electropositive element | <chemistry> An element whose atoms have a tendency to lose electrons and form positive ions (e.g., sodium). (05 Mar 2000) |
| element | <chemistry> One of the 103 known chemical substances that cannot be divided into simpler substances by chemical means. A substance whose atoms all have the same atomic number. Examples: hydrogen, lead, uranium.(See atom, matter, nuclide.) (16 Dec 1997) |
| trace element | Any chemical element that an organism needs very small quantities of tosurvive. (09 Oct 1997) |
| transitional element | <cell biology> Region at the boundary of the rough endoplasmic reticulum and the Golgi. Transport vesicles are responsible for the transfer of secretory proteins from this part of the rough endoplasmic reticulum to the Golgi system. (18 Nov 1997) |
| enhancer element | <molecular biology> A DNA sequence, present in the genomes of higher eukaryotes and of various animal viruses, which can increase the transcription of genes into messenger RNA. These control element frequently found 5' to the start site of a gene, when bound by a specific transcription factor, enhance the levels of expression of the gene, but are not sufficient alone to cause expression. Distinguished from a promoter, that is alone sufficient to cause expression of the gene when bound, in practice, the two terms merge. Enhancers usually can function in either orientation and at various distances from a promoter. Compare: promoter. (03 Jul 1999) |
| transposable element | <molecular biology> Small, mobile DNA sequences that can replicate and insert copies at random sites within chromosomes. They have nearly identical sequences at each end, oppositely oriented (inverted) repeats and code for the enzyme, transposase, that catalyses their insertion. Bacteria have two types of transposon, simple transposons that have only the genes needed for insertion and complex transposons that contain genes in addition to those needed for insertion. Eukaryotes contain two classes of mobile genetic elements, the first are like bacterial transposons in that DNA sequences move directly. The second class (retrotransposons) move by producing RNA that is transcribed, by reverse transcriptase, into DNA which is then inserted at a new site. (13 Nov 1997) |
| extrachromosomal element | Any heritable element not associated with the chromosome. It is usually a plasmid or the DNA of organelles such as mitochondria and chloroplasts. (18 Nov 1997) |
| androgen-binding proteins | Carrier proteins produced in the sertoli cells of the testis, secreted into the seminiferous tubules, and transported via the efferent ducts to the epididymis. Participate in the transport of androgens; include also synthetic androgens binding proteins. (12 Dec 1998) |
| 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) |
| binding | <biochemistry, chemistry, molecular biology> The adherence of molecules to one another, for example, enzymes to substrates, antibodies to antigens, DNA strands to their complementary strands. Binding occurs because the shape and chemical natures of parts of the molecules surfaces are complementary. A common metaphor is the "lock-and-key," used to describe how enzymes fit around their substrate. (14 Nov 1997) |
| binding constant | <chemistry> Reciprocal of dissociation constant. A measure of the extent of a reversible association between two molecular species at equilibrium. (18 Nov 1997) |