Abstract
Photosynthetic pigments, which undergo electron transfer reactions, are specifically associated with the D1-D2-Cytb559 protein complex. A particular aggregated state of in vivo chlorophyll a (Chl a) is responsible for the high-energy conversion efficiency. The Langmuir- Blodgett (L-B) technique allows preparation of systems that potentially mimic the packing of Chl a in vivo. Water has a pronounced effect on the optical and electrical properties of chl a L-B films, and is a key element in the formation of dimers with (anti) parallel transition moments of the constituent monomers. The incorporation of lipid makes the transport of photogenerated charge carriers more difficult. In the case of Chl a-Cytochrome c mixtures, keto groups of chl a play a major role in the pigment-protein association.