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Allosteric enzyme that is stimulated or inhibited by an effector or modulator molecule other than its substrate. For the enzyme threonine dehydratase the substrate is threonine and modulator is L-isoleucine. In many cases the effectors are end products of a metabolic pathway, and when they inhibit(which is usually the case) these effectors are called end product or feedback inhibitors. Kinetically feedback inhibitors are usually partially competitive in that they can be partially overcome by high concentrations of the substrate.  2, fiche 1, Anglais, - heterotropic%20enzyme

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A great many (if not most) allosteric enzymes are of mixed homotropic-heterotropic type, in which both the substrate and some other metabolite(s) may function as modulators.  3, fiche 1, Anglais, - heterotropic%20enzyme

Fiche 1,  Justifications,  Français

Record number: 1, Textual support number: 1 DEF

Enzyme allostérique stimulé ou inhibé par un effecteur ou un modulateur autre que leur substrat. Pour l'enzyme thréonine déshydratase, le substrat est la thréonine et le modulateur la L-isoleucine.  1, fiche 1, Français, - enzyme%20h%C3%A9t%C3%A9rotrope

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Fiche 2,  Justifications,  Anglais

Record number: 2, Textual support number: 1 DEF

Modification of enzymes, which is often, but not always, accomplished by the addition of a phosphate group to a specific serine, threonine, or tyrosine residue in the enzyme. The phosphate comes from ATP and its transfer is catalyzed by enzymes known as protein kinases... Phosphorylation alters the shape of an enzyme in such a way as to increase or inhibit its activity. The subsequent removal of the phosphate group, which reverses the effect of the phosphorylation, is achieved by a second enzyme, called a phosphoprotein phosphatase.  1, fiche 2, Anglais, - covalent%20modification

Record number: 2, Textual support number: 1 CONT

Nucleophilic catalysis is a specific example of covalent catalysis: the substrate is transiently modified by formation of a covalent bond with the catalyst to give a reactive intermediate. There are also many examples of electrophilic catalysis by covalent modification.  2, fiche 2, Anglais, - covalent%20modification

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Modulation réversible de l'activité enzymatique par la fixation covalente et transitoire de certains composés chimiques. L'exemple historique est celui des enzymes responsables du métabolisme contrôlé du glycogène. En fait, il s'agit ici du type de contrôle que peuvent exercer certaines hormones, dont la noradrénaline, sur des activités enzymatiques.  2, fiche 2, Français, - modification%20covalente

Record number: 2, Textual support number: 1 CONT

L'activité de nombreux enzymes est contrôlée, non pas par la formation de complexes entre enzymes et molécules régulatrices, mais par des modifications covalentes de l'enzyme. La plus connue de ces modifications est la phosphorylation/déphosphorylation des aminoacides hydroxylés; cette modification, catalysée dans un sens par une kinase, dans l'autre par une phosphatase, joue un rôle très important dans de nombreux mécanismes, comme par exemple la transmission de l'influx nerveux. [...] Un autre exemple de modification est [...] la transformation d'un proenzyme inactif en enzyme actif par coupure(s) protéolytique(s).  3, fiche 2, Français, - modification%20covalente

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Record number: 3, Textual support number: 1 CONT

Salmon meal is manufactured out of salmonids and is a full value protein source for feed stuffs manufacture for unproductive animals. The product is rich in lysine, methionine, threonine, cystine.  2, fiche 3, Anglais, - salmon%20meal

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Record number: 3, Textual support number: 1 CONT

La farine de saumon est produite à partir de tissus séchés et broyés de poissons dont les huiles ont été extraites. [...] Analyse typique: [...] Méthionine 2,14 % ; cystine 1,14 % ; lysine 5,38 % ; thréonine 3,28 % [...]  1, fiche 3, Français, - farine%20de%20saumon

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The amounts of acetaldehyde produced by the yoghurt bacteria are small, in the range of 5 to 10 ppm [parts per million]. Recent studies in our laboratory show a five-to ten-fold increase in acetaldehyde production as a result of extra added threonine... to the growth medium, an almost linear relationship between the level of acetaldehyde produced during milk fermentation and the threonine aldolase activity measured in different Streptococcus thermophilus strains. This clearly shows the importance of this enzyme in flavour formation in yoghurt.  1, fiche 4, Anglais, - threonine%20aldolase%20activity

Fiche 4,  Justifications,  Français

Record number: 4, Textual support number: 1 CONT

Un des composés aromatiques, caractéristique du yaourt est l'acétaldéhyde, qui ne provient pas du lactose, mais résulte de l'action d'une thréonine-aldolase, enzyme des lactobacilles dégradant l'acide aminé thréonine.  1, fiche 4, Français, - action%20d%27une%20thr%C3%A9onine%2Daldolase

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Fiche 5,  Justifications,  Anglais

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Aspartate kinase(AK) catalyzes the first reaction of common biosynthetic pathway of threonine, lysine and methionine in plants and bacteria.  2, fiche 5, Anglais, - aspartate%20kinase

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L'aspartate kinase (AK) catalyse la première étape de la biosynthèse commune à la thréonine, à la lysine et à la méthionine chez les plantes et les bactéries.  3, fiche 5, Français, - aspartate%20kinase

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Anderson and Warnick(3) conducted a series of studies to determine the most limiting amino acid in several commonly used feed ingredients. A basal ration formulated to contain 14% from the test ingredient and 4% protein from a mixture of amino acids was fed. One by one the amino acids were removed from the basal ration and chick performance noted. Methionine was found to be the first limiting amino acid insoybean meal. Threonine, valine and lysine were found to be marginal when soybean meal was the only source of protein in the ration.  1, fiche 6, Anglais, - basal%20ration

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Fiche 7,  Justifications,  Anglais

Record number: 7, Textual support number: 1 CONT

Overproduction of lysine, far beyond the bacterium's own needs, has been achieved by isolating two kinds of mutant. In one kind a mutation in the gene coding for the enzyme homoserine dehydrogenase abolishes the enzyme's activity and thereby prevents the bacterium from making threonine(one of the inhibitory products) and methionine.  1, fiche 7, Anglais, - homoserine%20dehydrogenase

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Record number: 7, Textual support number: 1 CONT

On a isolé deux mutants bactériens qui synthétisent la lysine bien au-delà de leurs besoins. Pour la première de ces souches surproductrices, une mutation du gène codant pour une enzyme, l'homosérine déshydrogénase, abolit son activité et empêche la bactérie de synthétiser la thréonine (un des produits inhibiteurs) et la méthionine.  1, fiche 7, Français, - homos%C3%A9rine%20d%C3%A9shydrogenase

Fiche 7,  Justifications,  Espagnol