Features of kinetic and regulatory processes in biosystems

Low Temperature Physics, Volume 47, Issue 3, Page 250-267, March 2021. A feature of biological systems is their high structural heterogeneity. This is manifested in the fact that the processes observed at the nanoscopic level are noticeably multistage in time. The paper expounds an approach that allows, basing on the methods of nonequilibrium statistical mechanics, to obtain kinetic equations that enable describing the evolution of slow processes occurring against the background of faster ones. Vibrational relaxation in electronic terms and stochastic deviations of the position of the electronic energy levels of the system from their stationary positions are considered the most important fast processes. As an example, it is shown how the kinetics of one- and two-electron transfer through protein chains, the oxygen-mediated transfer of a triplet excitation in the pigment-protein complex, the kinetics of temperature-independent desensitization of pain receptors, as well as conformational regulation of enzymatic reactions, can be described.