| f-2 generation | <genetics> Filial-Two generation. The generation of offspring which results from mating or genetically crossing members of the F-1 generation to each other. Members of this generation are two generations removed from the original parent generation, or the P generation. (09 Oct 1997) |
|---|---|
| F-factor | <molecular biology> A small piece of episomal bacterial DNA (plasmid) which provides bacteria with the ability to initiate conjugation (bacterial mating) with other nearby bacteria. It can be present as extrachromosomal protein or integrated into the bacterial chromosome, and effectively determines the 'sex' of the bacterium, host chromosome mobilization, transfer via conjugation of genetic material, and the formation of sex pili. During conjugation, the F-factor is copied and passed on to the other bacterium so that it acquires the ability to initiate conjugation also. (12 Jul 2000) |
| f-number | <radiobiology> In optics, denotes the ratio of the equivalent focal length of an objective lens to the diameter of its entrance pupil. (09 Oct 1997) |
| F-type ATPase | <enzyme> One of three major classes of ion transport ATPase, characterised by a multi subunit structure and a lack of a phosphorylated intermediate. See: ATP synthase, P-type ATPase, V-type ATPase. (18 Nov 1997) |
| F1 ATPase | <enzyme> Easily detachable cytosolic multi subunit component of the F1FO ATPase. (18 Nov 1997) |
| F1FO ATPase | <enzyme> An enzyme that hydrolyzes ATP into ADP and phosphate. (09 Oct 1997) |
| f2 fragment | <immunology> A fragment of an antibody protein which includes the antigen-binding portions but not the Fc section. They can be produced by treating whole antibodies with proteases that will specifically cleave off the Fc section. (09 Oct 1997) |
| F390 hydrolase | <enzyme> From methanobacterium thermoautotrophicum; catalyses hydrolysis of f390 into AMP and coenzyme f420 Registry number: EC 3.1.4.- (26 Jun 1999) |
| F390 synthetase | <enzyme> From methanobacterium thermoautotrophicum; catalyses formation of f390 from ATP and coenzyme f420 Registry number: EC 2.7.7.- (26 Jun 1999) |
| F420H2 dehydrogenase | <enzyme> Isolated from methanolobus tindarius; catalyses oxidation of f420h2 to f420 in final step of methanogenesis Registry number: EC 1.- (26 Jun 1999) |
| fa veolus | A small pit or depression. Origin: Mod. L. Dim. Of favus, honeycomb (05 Mar 2000) |
| FA virus | A strain of mouse encephalomyelitis virus. (05 Mar 2000) |
| Fab | <immunology> Fragment of immunoglobulin prepared by papain treatment. Fab fragments (45 kD) consist of one light chain linked through a disulphide bond to a portion of the heavy chain and contain one antigen binding site. They can be considered as univalent antibodies. (18 Nov 1997) |
| FAB classification | <haematology> The classification of acute myeloid leukaemia on the basis of bone marrow and peripheral blood features. M0: Acute myeloid leukaemia with minimal evidence of myeloid differentiation. M1: Acute myeloblastic leukaemia. M2: Acute myeloblastic leukaemia with differentiation. M3: Acute promyelocytic leukaemia. M4: Acute myelomonocytic leukaemia. M5: Acute monocytic leukaemia. M6: Acute erythroleukaemia. M7: Acute megakaryocytic leukaemia. Acronym: FAB (07 Apr 1998) |
| Fab fragment | The antigen-binding fragment of an immunoglobulin molecule, consisting of both a light chain and part of a heavy chain. Synonym: Fab piece. (05 Mar 2000) |