Logo
Home | Sitemap | Contact us | Search | Language
Select Your Theme
Left Home Right
Home >> Dictionary of Bioinformatics, Biochemistry, Biotechnology >> F Plasmid, FAD

F-actin Filamentous action composed of G-actin subunits.

F-duction The transfer of chromosomal genes by F’ strains at a very high frequency. Also termed sexduction.

F episome A large extrachromosomal circular double-stranded DNA molecule that carries bacterial fertility genes.

F plasmid A large, low-copy plasmid of E.coli. It is known as sex factor or fertility plasmid, because it permits mating between F+ and F- bacteria and confers the ability to function as a genetic donor during conjugation. Also called F factor.

F protein The Sendai virus-derived protein responsible for cell fusion.

F+ bacteria Bacteria that contain a fertility factor, which allows conjugation.

F2 generation The second filial generation, produced by crossing two members of the F1 generation, or by self-pollinating the F1.

Fab The antibody fragment that contains the antigen-binding site. This fragment is generated by papain treatment which cleaves at the hinge region generating two Fab fragments from one antibody molecule.

F(ab)2 fragment A portion of the lgG antibody molecule that contains two antigen binding domains but lacks the Fc region. These fragments are generated by treating antibodies with certain proteases that specifically cleave at the end of the Fc segment

Fabry disease An X-linked lysosomal storage disorder caused by a deficiency of a-galactosidase resulting in accumulation of the trihexoside, galactosyl-galactosylglucosylceramide. The clinical symptoms are severe in hemizygous males and include painful neuropathy, angiokeratoma, decreased sweating and corneal opacity. Cardiovascular manifestations include cardiac arrhythmias and lipid deposition in the myocardium leading to myocardial infarction. Lipid deposition in the kidney causes progressive renal impairment and renal failure. The disease usually affects young adults and is generally fatal. The symptoms are milder in heterozygous females. Administration of phenytoin is useful in the management of painful neuropathy. Renal complications can be treated by dialysis or transplantation. This disease is a suitable target for enzyme replacement therapy.

Factor X (Stuart Prower factor) A clotting factor that activates prothrombin to thrombin. Factor X is a glycoprotein with two subunits linked by disulphide bridges. One of the subunits contains the catalytic site and the other contains 12 g-carboxyglutamate (Gla) residues. Activation of Factor X is carried out in both the intrinsic and extrinsic pathways.

Factor XII (Hageman factor) A component of the contact stage of intrinsic pathway activated by surface contact or the kallikrein system. Factor XII and kallikrein and involved in a cyclic process termed reciprocal activation in which
Factor XIIa activates more kallikrein which generates additional Factor XIIa. Factor XIIa then activates Factor IX with high molecular weight kininogen as accessory factor.

F1 generation The first filial generation produced by crossing two parental homozygous lines.

F- bacteria Bacteria that are devoid of the fertility factor that allows conjugation.

F’ bacteria Bacteria that have an F plasmid containing one or more chromosomal genes.

F0F1 complex See ATP synthase.

Facilitated diffusion The transport of an ion or a small molecule across a cell membrane down its concentration gradient with the help of a protein transporter. This occurs at a rate greater than that obtained by passive diffusion. Also called facilitated transport.

FACS See fluorescence-activated cell sorting.

Factor VIII See antihaemophilic globulin.

F factor A bacterial plasmid that contains fertility genes necessary for conjugation. These genes are responsible for genetic transfer from donor cell to the recipient.

Factor XIII (fibrin-stabilising factor (FSF), fibrinoligase) A clotting factor that catalyses cross-linking of fibrin to form the hard clot. It is present in both plasma and platelets. Platelet FSF contains two identical a chains FSF (a2), whereas plasma FSF is made of two a and two b chains. Platelet FSF is converted to the enzymically active from FSFa2’ by the action of thrombin. Plasma FSF also requires Ca2+ for activation. Activated FSF is a transglutaminase that forms crosslinks between the fibrin monomers.

Factorial mating A type of mating in which each male parents is mated with each female parent. This is made possible in animals by in vitro embryo production. Such a mating method significantly reduces inbreeding in a selection programme.

Facultative aerobe An organism that can use oxygen for metabolism and can also live in anaerobic conditions.

Facultative anaerobe A microbe that normally lives under anaerobic conditions but is capable of utilising oxygen when placed in an aerobic environment.

Facultative cells Cells that can survive in the presence or absence of oxygen.

Facultative heterochromatin Inert state of sequences that also exist in active copies. For example, one of the two X chromosomes in mammalian females exists as a Barr body.

Facultative microorganisms See aerobe.

Facultative reabsorption Reabsorption of water facilitated by ADH. This occurs in the DCT and the collecting duct.

Facultative water excretion Urinary excretion of water beyond the obligatory requirement of 50 mL/day.

FAD Flavin adenine dinucleotide. A coenzyme that functions as an electron carrier during oxidation-reduction reactions. FAD consists of a phosphorylated riboflavin molecule linked to adenosine monophosphate (AMP). FAD functions as a hydrogen acceptor in dehydrogenation reaction, and is reversibly reduced to FADH2 FADH2 so formed is in turn oxidised to FAD by the electron transport chain, generating two molecules of ATP. FAD is a prosthetic group of D-amino acid dehydrogenase, xanthine oxidase and acyl CoA dehydrogenase.

Flavin Adenine Nucleotide
Left Home Right
Home | Sitemap | Terms | Privacy Policy | Contact us |
Language >> English | Français | Español | Deutsch | Italiano | Portugues | Japanese | Korean | Sim-Chinese