Transmembrane proton translocation in the photosynthetic membranes of the purple bacteriumRhodobacter sphaero-ides is driven by light and performed by two transmem-brane complexes; the photosynthetic reaction center and the ubiquinol–cytochromecoxidoreductase complex, coupled by two mobile electron carriers; the cytochrome and the quinone. This paper focuses on the kinetics and thermo-dynamics of the interaction between the lipophylic electron carrier ubiquinone-10 and the photosynthetic enzyme reconstituted in liposomes. .
