Biochemistry liver

The composition of the liver includes: water (70-75%), simple and complex proteins (12-24%) and products of their decay, lipids (2-6%), carbohydrates (2-8%) and their cleavage products, co-enzymes, vitamins, hormones, various low-molecular organic substances and mineral cations and anions. P. performs very important functions. It is widely represented processes of biosynthesis and processes of splitting all the major biologically compounds, synthesis of deoxyribo - and ribonucleic acids (DNA and RNA), a variety of di - and mononucleotides, purine and pyrimidine bases. At the same time in the liver enzymes are present, thanks to which nucleic acids and nucleotides are split, and the free purine bases - deamination and oxidation and thus serve as a source for the formation of oxipurinol and, in particular, of uric acid in humans or allantoin most mammals. In Petrograd, the synthesis of protein, since the activation of amino acids in hyaloplasm, education connection with specific for each amino acid transport RNA to the final stage of synthesis - release long peptide chains ready proteins from their place of education in polinomakh. In Petrograd, not only formed proteins characteristic of it, but also the proteins of blood plasma albumin, many globulins and fibrinogen and other factors involved in blood clotting process. Under the influence katiepricesex proteases and peptidases in the liver is the splitting of proteins and the formation of amino acids. Along with amino acids, brought by blood, they represent the metabolic Fund, from which the body derives the necessary connections for the processes of metabolism. In the liver amino acids undergo various transformations: the pereaminirovanii, deamination, decarboxylation, leading to the formation of biogenic amines; as a result of the transfer of the methyl group, owned by pre-synthesized adenosylmethionine, provides education choline, creatine, adrenaline and other methylated connections.
Kind and characteristic way of turning in Petrograd individual amino acids such as tryptophan, phenylalanine, histidine, lysine, etc. From tryptophan, in particular, occur such biologically active substances, as tryptamine, oxitriptofana and the product it decarboxylation serotonin, quinolinic acid and both her decarboxylation: nicotine and pikaliiva acid; from histidine formed formamidopyrimidine and glutamic acid, and histamine; from arginine formed urea and ornithine. Ornithine takes typical cycle of reactions leading to the synthesis of the final product sharing simple proteins - urea from carbon dioxide and ammonia, with the participation of magnesium, ATF and some amino acids. In the liver widely presents the so-called neutralizing syntheses aimed at neutralization of toxic products, such as phenols, aromatic hydrocarbons, terpenes forms hippuric and fencerows acids, when using glycine, and paired glucurone Efrosinya acids, mercaptoacetate and other compounds.
In Petrograd there are processes of synthesis and decomposition of carbohydrates. Under the influence of phosphorylase end glucose remains of glycogen otdalyayutsya education Glu-Kozo-1-phosphate. This substance is involved in the formation of urediniospores transport forms glucose residues and their main source in the synthesis of glycogen. Violation of enzymatic transformation of galactose-1-phosphate in Glu-Kozo-1-phosphate causes severe pathological phenomena associated with a genetic disease - galactosemia. The usual way of conversion of glucose-1-phosphate (education out of him glucose-6-phosphate) is of great biological importance, as this connection plays a Central role in the transformation of carbohydrates and self-regulation of carbohydrate metabolism. In the liver glucose-6-phosphate brakes sharply phosphorylytic the glycogen breakdown, activates ferment transport glucose from urediniospores on the skeleton of glycogen in its synthesis, is a substrate for oxidative transformation of glucose in pantanaw cycle. Biological role: education in the oxidation of glucose-6-phosphate restored form of nicotinoyldihydrocodeine (NADRR), the necessary participant recovery synthesis of fatty acids and cholesterol, and the conversion of glucose-6-phosphate in fotopatos - mandatory component in the formation of nucleotides and nucleic acids. In addition, glucose-6-phosphate is a substrate for further glycolytic transformations that lead through fructose-mono - and diphosphate to fosforikum and education pyruvic and lactic acid. This process is important for plastic exchange in connection with the formation of compounds needed for biosynthesis, and plays a significant role in the exchange of energy products each molecule of lactic acid equivalent to the synthesis of one energy-rich phosphate bonds in the molecule ATP. Finally, the breakdown of glucose-6-phosphate phosphatase ensures the supply of blood-free glucose delivered the blood flow to all organs and tissues.
In respect of the exchange of simple and complex fat liver performs a dual role: on the one hand, it is a degradation of fat and fatty acid oxidation, and on the other, in P. presents enzyme biosynthesis system of high-molecular fatty acids, neutral fat and lipoid complex; intermediate product in these syntheses is phosphatidic acid.
Proved the possibility of synthesis in Petrograd also cholesterol held not less than thirty separate stages of which are crucial to the formation of mevalonova acid. When entering the digestive tract cholesterol enzymatic the formation of mevalonova acid is terminated on the basis of feedback, and stops synthesis of cholesterol.
Formed by degradation of fat fatty acids undergo oxidation with the formation of acetyl coenzyme a, coming in the presence of the condensing enzyme reaction with Savelevoj acid and forming thus citric acid is a typical substrate oxidative transformations of the Krebs cycle (see biological Oxidation). In the liver cells, as in other bodies, oxidative transformation localized mainly in the mitochondria, associated with the formation of the energy-rich compounds (ATP) and end education CO2 and H2o
P. plays a significant role in pigmentary exchange (see); it is the destruction of hemoglobin, education bilirubin and its transformation into soluble form, in the form of diglucuronide bilirubin.
In the mineral water-salt metabolism and in the persistence of the acid-alkaline ratio P. participates. Mineral substances in Petrograd are partly free and partly are part of complex organic compounds, such as enzymes (magnesium, manganese, iron, copper, zinc). Cations are also activators of enzymes, such as sodium, potassium, calcium, Nickel, cobalt, chrome, etc. as part of Peterhof is iron-containing protein, ferritin, copper-containing protein haptocorrin; these substances participate in the process of blood.
The liver contains b vitamins, vitamin C, b vitamins D and fat-soluble vitamins E and K. From carotene in P. formed vitamin A.
The metabolic processes taking place in Petrograd, are regulated by the nervous system, both directly and under the influence of the hormonal factors (adrenaline, insulin, glucagon, corticosteroids, and hormones produced by the pituitary gland). In turn, the cells of P. via afferent fibers have an effect on the functional state of the Central nervous system. The diversity and interdependence of the factors influencing the state of the cells of P., determine both the magnitude and direction of current processes of metabolism.