Benders'dictionary of nutrition and food technology

477toxopyrimidine Antimetabolite of vitamin B 6 released by theaction of thiaminase ii on thiamin.TPM See total polar materials.TPN Total parenteral nutrition.TQM Total quality management.trabecular bone Thin bars of bony tissue in spongy bone.traceability Of foods, the ability to relate each batch of productboth back to the individual ingredients, their suppliers and thedelivery dates, and forward to the packages supplied and theirdistribution to shops and final consumers.trace elements See minerals, trace; minerals, ultratrace.tracers See isotopes.traife Foods that do not conform to Jewish dietary laws; the oppositeof kosher.Trailblazer TM fat replacer made from protein.trans- See isomers (3).transaminase Enzymes (EC 2.6.1.x, also known as aminotransferases)that catalyse the reaction of transamination; the transferof the amino group from an amino acid donor onto aketo-acid (oxo-acid) acceptor, yielding the keto-acid (oxo-acid)carbon skeleton of the donor and the amino acid correspondingto the acceptor. The enzymes are pyridoxal phosphate (vitaminb 6 )-dependent, and the activation of either alanine (EC 2.6.1.2)or aspartate (EC 2.6.1.1) aminotransferase apo-enzyme in redblood cells by pyridoxal phosphate added in vitro provides anindex of vitamin B 6 status. An activation coefficient above 1.25(alanine aminotransferase) or 1.8 (aspartate aminotransferase)is indicative of deficiency.transcription The process whereby one strand of the region ofDNA containing the information for one or more proteins iscopied to yield RNA, catalysed by RNA polymerase (EC2.7.7.6).transcription factors The various proteins in addition to RNApolymerase that are required for transcription of DNA to formmRNA.See also transcriptomics; translation.transcriptomics The genome of an organism is, subject to mutation,constant, and analysis of a genome does not tell uswhich genes are expressed in which tissue, at what stage in development,or in response to environmental, nutritional andhormonal stimuli. This is the science of transcriptomics –identification of which genes are active (i.e. being transcribed) inthe organism, tissue or cell at different times and under differentconditions.See also genomics; metabolomics; proteomics; transcription.