|
Home >> Dictionary of Bioinformatics, Biochemistry, Biotechnology >> Agarose Gel Electrophoresis Airlift Fermenter
|
|
Agarose A crosslinked polysaccharide isolated from red algae and used as a support medium for the separation of molecules by various techniques such as gel electrophoresis, electroimmunodiffusion and immunoelectrophoresis.
Agarose gel electrophoresis A technique used for the separation of nucleic acids or proteins according to their size. The sizes of fragments that are separated depend on the percentage of agarose in the gel.
Aggregate 1. A clump or mass formed by gathering or collecting. 2. A serological reaction (aggregation) in which the antibody and antigen react and precipitate out of solution. 3. A body of loosely associated cells, such as a friable callus or cell suspension.
|
Aggregation An abstraction in which relationship sets are treated as higher-level entity set and can participate in relationships.
Aggregation technique A technique used in model organism studies in which 8-cell stage embryos are pushed together to yield a single embryo. This is used as an alternative to microinjection.
Aglucerase A modified from of β-glucosidase prepared from human placenta.
Aglycone The nonsugar part of a glycoside. Cleavage of the glycoside bond of a glycosides results in the formation of a sugar and an aglycone.
Agonist A drug, hormone or transmitter that forms a complex with a receptor site triggering an active response from a cell.
Agricultural biological diversity See agro-biodiversity.
|
Agricultural biotechnology (Agbio) The application of rDNA technology to agriculturally important plants and organisms.
Agrobacterium A genus of bacteria that includes several plant pathogenic species, causing tumour-like symptoms. See Agrobacterium tumefaciens; crown gall; hairy root culture; Ri plasmid; Ti plasmid.
Agrobacterium-mediated transformation A method of DNA transfer from the bacterium A. tumefaciens to plants.
Agrobacterium tumefaciens A soil bacterium that causes crown gall disease in dicotyledonous plants. The bacterium infects a would, injecting a short segment of DNA into some of the cells around the wound. The DNA comes from a large plasmid-the Ti (tumour induction) plasmid-a short region of which called T-DNA (transferred DNA) is transferred to the plant cell, where it causes the cell to grow into a tumour-like structure.
|
|
The T-DNA contains genes which inter alia allow the infected plant cells to make two unusual compounds, nopaline and octopine, that are characteristic of transformed cells. The cells form a gall, which hosts the bacterium. This DNA-transfer mechanism is exploited in the genetic engineering of plants. The Ti plasmid is modified so that a foreign gene is transferred into the plant cell along with or instead of the nopaline synthesis genes. When the bacterium is cultured with isolated plants cells or with wounded plant tissues, the new gene is injected into the cells and ends up integrated into the chromosomes of the plant.
Agrobiodiversity; agricultural biological diversity That component of biodiversity that has relevance in food and agriculture production. This includes within-species, species and ecosystem diversity.
|
|
|
Akt Also known as protein kinase B or PKB. It is a serine/threonine kinase that prevents apoptosis of neurons.
ALA (5-aminolaevulinate) The product of the condensation between succinyl CoA (active succinate) and glycine followed by rapid decarboxylation, the first step in the biosynthesis of haem catalysed by ALA synthase.
ALA synthase An enzyme that catalyses the rate-limiting step in porphyrin biosynthesis and is subject to feedback inhibition by haem. It requires Pyridoxal phosphate as cofactor. See ALA.
Alagille syndrome A rare, inherited liver disease in which there is accumulation of bile in the liver due to a lack or deficiency of bile ducts. This disease occurs in infants and children d is characterised by jaundice, stunted growth and deformities.
Alanine An aliphatic amino acid containing a methyl (-CH3) group as its side chain.
Alanine cycle A pathway in which alanine from the muscle is taken up by the liver, transaminated to pyruvate, converted to glucose and transported back to muscle.
|
AI See artificial insemination.
AIDS (acquired immunodeficiency syndrome). a generally fatal human disease in which the immune system is destroyed by a retrovirus (Human Immunodeficiency Virus, HIV). The virus infects and destroys helper T-cells, which are essential for defence against infections.
Airlift fermenter A cylindrical fermentation vessel in which the cells are mixed by air. The air which enters from an inlet at the base of the vessel rises through the column of culture medium. The gradient of air bubbles in different parts of the reactor brings about circulation of the cell suspension around the column.
Akinete A resting spore of the blue green alga Cyanobacterium.
Agents In bioinformatics, refers to independent, autonomous, software modules that can search the Internet for data or content with respect to a particular application, such as a gene, protein, or biological system.
Ageusia Lack of impairment pf the sensation of taste.
Agglutination Clumping of cells to one another by binding of molecules to the cell surface. See haemagglutination.
Agglutination inhibition A modification of the agglutination reaction that provides a highly sensitive assay system to detect small quantities of an antigen.
Alanine transaminase (ALT) Formerly known as glutamate pyruvate transaminase (GPT). An enzyme that catalyses the transfer of amino groups of alanine to 2-oxoglutarate forming glutamate and pyruvate. ALT is found in high amounts in the liver with smaller quantities in the heart, kidney and skeletal muscle. ALT is predominantly cytosolic. Plasma ALT is a more specific indicator of liver damage than AST.
Alarmones Unusual dinucleotides containing multiple phosphate groups. These are synthesised by bacteria under conditions of stress and function like hormones to regulate bacterial metabolism.
Albinism Hereditary absence of melanin pigment due to absence of tyrosinase. Albino animals lack colour in their skin, hair and eyes. In plants, refers to absence of chlorophyll.
Albino 1. An organism that lacks pigmentation, as a result of genetic factors. 2. A plastome (plastid) mutant with loss of chlorophyll.
Albumin The most abundant heat-coagulable, water soluble protein found in egg white and blood plasma. It is a single polypeptide chain with a molecular weight of approximately 66,000 containing 580 amino acid residues and 17 intrachain disulphide bonds. It folds to form three structural domains and nine subdomains. About 14 g/dL of albumin is synthesised by the liver. Approximately, 40 per cent of albumin is present in circulation and the remainder is in the extravascular space of tissues, chiefly in the skin, muscle and intestine. Albumin has a major role in osmotic regulation and transport of substances that are sparingly soluble in water. Albumin exerts antioxidant activity by binding free fatty acids, bilirubin, divalent cations and HOCI. Albumin also exhibits buffering action and anti-inflammatory effects.
|
|
