VYSOKOERGICHESKY CONNECTIONS

From Big Medical Encyclopedia

VYSOKOERGICHESKY CONNECTIONS (synonym makroergichesky connections) — group of the natural substances containing high-energy bonds; chemical (enzymatic) transformations of these substances are followed by release of a large amount of energy, edge then is spent for various processes of life activity: the movement, biosynthesis of a series of compounds, transport of ions and other substances through membranes, etc. Biol, value B. of page is caused by their central position in a reaction chain metabolism and energy (see), proceeding in a live organism. Chemical communication in V.'s molecule of page, a gap a cut is followed by allocation of energy, it is accepted to call vysokoergichesky (makroergichesky) or high-energy communication. The quantitative characteristic of vysokoergichesky communication since she allows to estimate thermodynamic probability of course of process is important, in Krom B take part. page. The energy which is released at V.'s rupture of page in this or that biochemical process, is not equivalent to the energy of vysokoergichesky communication. In actual practice the rupture of vysokoergichesky communication is always followed by transfer of the group which is chipped off from V. by page on a molecule of any acceptor (e.g., in case of hydrolytic disintegration such acceptor is the water molecule). Thus, the energy which is released at V.'s splitting by the village is measured by change of free energy in reaction of transfer by the connected vysokoergichesky communication of group of atoms on a molecule of an acceptor. In this regard instead of accepted in biochemical, literature of the term «vysokoergichesky connections» sometimes use the term of «connection with the high potential of transfer of groups». As changes of free energy in reactions of transfer of group depend on the chemical nature of the donor and an acceptor, for the potential of transfer of groups change of free energy at transfer 1 can be accepted asking vysokoergichesky connection (donor) on a standard acceptor (usually water) in the conditions of standard concentration, temperature, active reaction of the environment etc.

The clear boundary between connections with the high and low potential of transfer of groups does not exist. It is conditionally considered to be V. page such substances, for to-rykh the size of standard free energy of hydrolysis is more negative, than — 7 kcal/mol. With a high potential of transfer of groups

the extensive class of organophosphorous connections including anhydrides phosphoric to - you, acylphosphates, guanidinephosphates and enolfosfata, and also a number of thiol ethers and ethers of amino acids is among biochemical important substances. Among them takes the central place adenosine triphosphoric to - that (see. Adenozinfosforny acids ), significant amounts a cut contain in vegetable and animal fabrics.

See also Bio-energetics , biological oxidation .


Bibliography: Shave D. and Whyte K. Kinetik and thermodynamics of biochemical processes, the lane with English, M., 1059; To l about t of c of I. Energetik of biochemical reactions, the lane with English, M., 19 70, bibliogr.; M and l of e r G. and To about r d e with Yu. Fundamentals of biological chemistry, the lane with English, M., 19 70.

Yu. N. Leykin.

Яндекс.Метрика