The spectral-kinetic indicators of relaxation processes following the electron stabilization into the acceptor compartment of photosynthetic RCs of bacteria

Long term temporary stabilization of the electron in the acceptor part of the photosynthetic reaction center (RC) is essential for subsequent efficient trans fer of reducing equivalents to the photosynthetic membrane. Comparative study of the kinetics of redox reactions of photoactive bacteriochlorophyll of the RC of purple bacteria and quinone acceptors in their indi vidual absorption bands is an informative approach to study the mechanisms of this stabilization. The analy sis of the revealed kinetic differences makes it possible to estimate the activation energy and the characteristic time of the transition relaxation process associated with the stabilization of the electron on the final quinone acceptor and establish the hydrogen bonds in the quinone environment that are involved in this process.