OXALOACETIC ACID — dicarboxylic acid, HOOC-C(OH) = SN — СООН. Y. - at.k. is mother substance of the major recycling — a cycle tricarboxylic to - t (see Tricarboxylic acids a cycle). A shortcoming oxalacetic to - you break a normal current of this cycle and causes serious frustration of a metabolism and energy (see). Y. - at. to. is the substance connecting among themselves carbohydrate metabolism (see) and exchange of amino acids (skhm.), besides, she takes part in processes of transamination (see).
In the nature Shch. - at. to. exists in the form of two tautomeric forms (see Taitomeriya) — enol and ketonic (NOOS — WITH — CH2 — СОÄì, ke-toyantarny to - that) and in a look cis-and a Torah «with - isomers (see the Isomerism). Trans-isomer Shch. - at. to. call also oxyfumaric to - that (see Fumaric acid), and >^шизомер — ok ~ simaleinovy to - that. Salts and ethers Shch. - at. to. call oxaloacetates.
Pier. the weight (weight) oxalacetic to - you is equal to 132,07. Cis-isomer represents colourless crystals with g°pl152 °, water soluble, alcohol, acetone, ethyl acetate, insoluble in benzene and chloroform. Grbshs-izomer — colourless crystals with £ °pl 184 °, during the heating to 50 ° it passes into tswc-isomer. In acid solutions Shch. - at. to. it is decarboxylized (see Decarboxylation). Quantitatively Shch. - at. to. determine colorimetric (see Colorimetry) in the form of 2,4-dinitro-phenythydrazone or manometrical by the volume of the carbon dioxide (see Anhydride of carbonic acid) emitted at decarboxylation oxalacetic to - you. In an organism of animals and the person Shch. - at. to. it is synthesized from pyruvic acid (see) and C02 carbon dioxide or formed of aspartic acid (see) in the course of transamination.
At a shortcoming oxalacetic to - you in a liver the acetyl groups not capable to oxidation collect, to-rye begin to turn quickly into ketone bodies (see). Their excess education leads to development of a metabolic acidosis (see) and to others patol. to states. The ketosis which is usually accompanying balance upset between oxidation of fats (see) and a catabolism of carbohydrates (see) arises in all cases of relative shortage Shch. - at. to. in comparison with KOA when atsetil-KOA cannot enter completely condensation with oxaloacetate (i.e. the first reaction of a cycle tricarboxylic to - t). Such shortcoming Shch. - at. to. it can be created in the conditions of need of metabolizing for a liver of large amounts of alcohol, at starvation (see) or a diabetes mellitus (see a diabetes mellitus).
Bibliography: Berezov T. T. and To
rovkin B. F-Biological chemistry, page 203, 512, M., 1982; To r yu Zh. Biokhimiya Medical and biological aspects, the lane with fr., page 372, M., 1979.
N. G. Budkovskaya.