[Theoretical analysis of the relation between the cell state and pathways of carbon isotope fractionation in metabolic processes].

On a dynamic model of fractionation of carbon isotopes in the living cell there are considered relationships between the distribution of carbon isotopes in the structures approximating basic biochemical fractions, their isotopic composition and parameters characterizing the dynamics of carbon metabolism, i.e. efficient carbon isotope separation factor in pyruvate enzymic decarboxylation, degree of its transformation at primary and secondary decarboxylation and ratios between the currents of carbon substrates. A wide range of variations of cell isotope parameters resulting from the change of its functional states was revealed. Possible applications of the relationships observed for studying biological systems are shown.