Food Biotechnology — page 10 of 34

Food Biotechnology terms

901. donor junction site The junction between the 5' end of an exon and the 3' end of an intron. See: acceptor junction site.
902. donor plant See: ortet.
903. Dormancy A period in which a plant does not grow, awaiting necessary environmental conditions such as temperature, moisture, nutrient availability.
904. dosage compensation A regulatory mechanism for sex-linked genes, to allow equivalent levels of gene expression from (in mammals) XY or XX genotypes, even though the gene copy…
905. double crossing-over The formation of two chiasmata within a chromosome arm, leading to the generation of a double recombinant gamete with respect to genes located within the…
906. double fertilization A process, unique to flowering plants, in which two male nuclei, which have travelled down the pollen tube, separately fuse with different female nuclei…
907. Double helix Describes the coiling of the antiparallel strands of the DNA molecule, resembling a spiral staircase in which the paired bases form the steps and the…
908. double recessive An organism homozygous for a recessive allele at each of two loci.
909. double-stranded complementary DNA (Abbreviation: dscDNA ). A double-stranded DNA molecule created from a cDNA template.
910. Double-stranded complementary DNA (dscDNA) A duplex DNA molecule copied from a cDNA template.
911. double-stranded DNA (Abbreviation: dsDNA ). Two complementary strands of DNA annealed in the form of a double helix. Synonym: duplex DNA.
912. doubling time (DUH-bling...) In biology, the amount of time it takes for one cell to divide or for a group of cells (such as a tumor) to double in size.
913. down promoter mutation A mutation that decreases the frequency of initiation of transcription. This leads to a fall in the level of mRNA compared to the wild type state.
914. down-regulate To induce genetically a reduction in the level of a gene's expression.
915. downstream The region extending in a 3' direction from a gene.
916. downstream processing A general term for biotechnological processes which follow the biology, i.e. fermentation of a micro-organism or growth of a plant.
917. Drift See: genetic drift.
918. Drosophila melanogaster The fruit fly, used for many years as a model for eukaryotic genetics. Of the nearly 300 disease-causing genes in the human genome, more than half have an…
919. drug Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition.
920. drug delivery Method by which a drug is delivered to its site of action. For traditional drugs this is another name for formulation.
921. dry weight The weight of tissue obtained following sufficiently prolonged oven-drying at high temperature to remove all water.
922. dscDNA See double\-stranded complementary DNA.
923. dsDNA See: double-stranded DNA.
924. dTTP Rarely used but strictly correct abbreviation for deoxythymidine 5'-triphosphate. Required for DNA synthesis since it is a direct precursor molecule.
925. dual culture A culture made of a plant tissue and one organism (such as a nematode) or an obligate parasite/micro-organism (such as a fungus).
926. Duplex DNA Double-stranded DNA.
927. duplication Multiple occurrence of: 1. A DNA sequence within a defined length of DNA; or 2. A specific segment in the same chromosome or genome.
928. E site See: exit site.
929. E. coli See: Escherichia coli.
930. EBV A common virus that remains dormant in most people. It causes infectious mononucleosis and has been associated with certain cancers, including Burkitt…
931. EC See: Enzyme Commission number.
932. ecdysone A steroid hormone in insects stimulating the synthesis of proteins involved in moulting and metamorphosis.
933. eclosion 1. Emergence of an adult insect from the pupal stage. 2. Initial phase of germination of fungal spores.
934. ecological diversity See: biodiversity.
935. Ecology The study of the interactions of organisms with their environment and with each other.
936. economic trait locus (Abbreviation: ETL). A locus influencing a trait that contributes to producer's income.
937. Ecosystem A complex ecological community or environment forming a functioning whole.
938. ecotype A population or a strain of an organism that is adapted to a particular habitat.
939. ectopic Anomalous situation or relation, particularly with respect to pregnancy, where the foetus is implanted outside the uterus.
940. edible vaccine Edible antigen-containing material, that activates the immune system via gut-associated lymphoid tissues.
941. editing See: splicing (1).
942. EDTA See: ethylenediamine tetraacetic acid.
943. EDV Abbreviation for essential derivation of varieties.
944. effector cells Cells of the immune system that are responsible for the production of cell-mediated cytotoxicity.
945. effector molecule A molecule that influences the behaviour of a regulatory molecule, such as a repressor protein, thereby influencing gene expression.
946. egg 1. The fertilized zygote in egg-laying animals. 2. The mature female reproductive cell in animals and plants.
947. EGS See: external guide sequence.
948. EIA Electronic Industries Association EIM
949. elastin A fibrous protein that is the major constituent of the yellow elastic fibres of animal connective tissue.
950. electro-blotting The electrophoretic transfer of DNA, RNA or protein from a gel, in which they have been separated, to a support matrix, such as nitrocellulose.
951. electrochemical sensor Biosensors, such as an enzyme electrode, in which a biological process is harnessed to an electrical sensor system.
952. electron microscope (ee-LEK-tron MY-kroh-SKOPE) A microscope (device used to magnify small objects) that uses electrons (instead of light) to produce an enlarged image.
953. Electrophoresis a technique for the separation of charged molecules by migration on a support medium under the influence of an electrical charge.
954. Electroporation A method for transforrning DNA, especially useful for plant cells, in which high voltage pulses of electricity are used to open pores in cell membranes…
955. ELISA Abbreviation for enzyme-linked immunosorbent assay. An immunoassay, i.e. an antibody -based technique for the diagnosis of the presence and quantity of…
956. elite tree A phenotypically superior tree in a tree breeding programme.
957. elongation factors Soluble proteins required for the elongation of polypeptide chains on ribosomes.
958. Embryo Early stage in the development of a plant or an animal. In vertebrate animals (have a backbone or spinal column), this stage lasts from shortly after…
959. embryo cloning The creation of identical copies of an embryo by embryo splitting or by nuclear transfer from undifferentiated embryonic cells.
960. embryo culture The culture of embryos on nutrient media.
961. embryo multiplication and transfer (Abbreviation: EMT). The cloning of animal embryos and their subsequent transfer to recipients via artificial inembryonation.
962. embryo rescue A sequence of tissue culture techniques utilized to enable a fertilized immature embryo resulting from an interspecific cross to continue growth and…
963. embryo sac The mature female gametophyte in angiosperms. Generally a seven-celled structure - two synergids, one egg cell, three antipodal cells (each with a single…
964. embryo sexing The determination of the sex of an embryo prior to birth. Typically achieved by the polymerase chain reaction -mediated amplification of DNA extracted…
965. embryo splitting The splitting of young embryos into several sections, each of which develops into an animal. A form of animal cloning, i.e.
966. embryo storage Cryogenic preservation of animal embryos, allowing inembryonation or other manipulations long after embryo formation.
967. embryo technology Generic name for any modification of mammalian embryos. It encompasses embryo cloning, embryo splitting, embryo storage, and in vitro fertilization.
968. embryo transfer (Abbreviation: ET). See: embryo multiplication and transfer, multiple ovulation and embryo transfer.
969. embryogenesis 1. (General) Development of an embryo. 2. (In plants) In vitro formation of plants from plant tissues, through a pathway closely resembling normal…
970. embryoid Plant biotechnology term no longer commonly used. An embryo-like body developing in vitro, forming a complete, self-contained plantlet with no vascular…
971. Embryonic stem (ES) cells Cell lines derived from early embryos that have the potential to differentiate into all types of somatic cells as well as to form germ line cells, and…
972. Embryonic stem cells (Abbreviation: ES cells). Cells of the early embryo that can give rise to all differentiated cells, including germ line cells.
973. emission wavelength The specific wavelength of light emitted by a fluorescent molecule, such as a labelled probe, upon absorption of light at the (higher) excitation…
974. EMT See: embryo multiplication and transfer.
975. Encapsidation Process by which a virus' nucleic acid is enclosed in a capsid. See Coat protein.
976. encapsulating agents Anything which forms a shell around an enzyme or bacterium, common agents being polysaccharides such as alginate or agar.
977. encapsulation Any method packaging an enzyme or bacterium and maintaining its normal functions. Used to immobilize cells in a bioreactor.
978. encode The gene product specified by a particular nucleic acid sequence. See: genetic code.
979. end-labelling The introduction of a readily-visualized tag at the end of a DNA or RNA molecule.
980. end-product inhibition The inhibition of an enzyme by a metabolite. Typically, the enzyme is the first enzyme in a biosynthetic pathway, and the metabolite the product of the…
981. Endangered species A plant or animal species in immediate danger of extinction because its population number has reached a critical level, or its habitat has been…
982. Endemic Where disease occurs on a consistent basis.
983. endocrine gland Any gland in an animal that manufactures hormones and secretes them directly into the bloodstream to act at distant sites in the body, known as target…
984. endocrine interference Interference with the normal balance of hormones.
985. endocytosis The process by which materials enter a cell without passing through the cell membrane.
986. Endoderm The internal layer of cells of the gastrula, which develops into the alimentary canal (gut) and digestive glands of the adult.
987. endodermis The layer of living cells, with various characteristically thickened walls and no intercellular spaces, which surrounds the of certain plants and occurs…
988. endogamy See: inbreeding.
989. endogenous Produced inside an organism or cell. The opposite is external (exogenous) production.
990. Endogenous retrovirus Integrated retrovirus DNA (provirus) derived from infection of the germline of an ancestral animal.
991. endomitosis Duplication of chromosomes without division of the nucleus, resulting in a doubling (or more) in the chromosome number within a cell.
992. Endonuclease See Nuclease.
993. Endophyte An organism that lives inside another.
994. endoplasmic reticulum (Abbreviation: ER). A cytoplasmic net of membranes, adjacent to the nucleus, visible under the electron microscope. The sites of protein synthesis.
995. endopolyploidy The net result of endomitoses. The somatic chromosome number has doubled (or more), forming a polyploid cell line.
996. endoprotease An enzyme that cleaves internal peptide bonds within a polypeptide molecule. Site of cleavage is usually specific to certain amino acid residues.
997. endoreduplication Chromosome reproduction during interphase. Four-chromatid chromosomes (diplochromosomes) are seen during this phase.
998. endosperm The nutritive tissue that develops in the seed of most angiosperms, containing varying proportions of carbohydrate (usually starch), protein and lipid.
999. endosperm mother cell One of the seven cells of the mature plant embryo sac, containing the two polar nuclei and, which, following fertilization, gives rise to the primary…
1000. endotoxin A component of the cell wall of gram-negative bacteria that elicits, in mammals, an inflammatory response and fever.