Ultrafast Transfers of Electronic Excitation and Electron in Photosynthetic Reaction Centers.

Abstract

A brief review is given on how ultrafast laser spectroscopy has been recently applied to the research of photosynthetic reaction center, which achieves the most essential energy conversion from light to chemical (physiological) energy. Photosystem I reaction center (PSIRC) is one of the several types of photosynthetic reaction center, and it is working in plants and some photosynthetic bacteria. Light-illuminated PSIRC generates the highest reducing capability among all biological systems, which is necessary for the reduction of carbon dioxide, the most controversial greenhouse effect gas. The understanding on PSIRC has been relatively delayed due to its stoichiometric and spectroscopic complexity. Thanks to the advance of ultrafast laser spectroscopy and the finely determined crystal structure in 2001, very detailed picture is being rapidly constructed on the mechanism of the electronic excitation transfer and the primary charge separation processes among the constituent chlorophylls in PSIRC.