Abstract

We consider here the electronic deactivation pathway/process of the carotenoid-chlorophyll complex following photoabsorption/activation. We point out the reasoning why the conventional Fӧster-Dexter (FD) approach, or deexcitation via tunneling, or paths through conical intersections are not compatible with all experimental data for this system. The proposed Bio-Auger (B-A) process discussed in connection with deactivation of the electronically excited thymine dimer when bound to the photolyse protein (photoactivated photolyase-protein complex) provides a suitable understanding of all observed experimental facts/data, that is, of all charge and energy transfers, radiationless transitions, and the overall de-excitation process. In addition, it leads to a current loop in the two light harvesting complexes: LHI and LHII. The current loop in LHII generates a magnetic field in the reaction center (RC) located inside that loop. Thus, electrons and other charged particles in the RC will move in one particular direction, as experimentally observed.

Keywords: Photosynthesis, Carotenoid, Chlorophyll, Bio-Auger process