Living things use solar energy in two ways: in the transmission of information and in the conversion of light energy to chemical energy. In order to elucidate the molecular mechanisms of highly sensitive visual responses and other photosensitive responses of biological systems, and the very efficient transduction of photoenergy to chemical energy in photosynthesis, it is important to observe molecular processes in biological systems. Using highly developed laser spectroscopic techniques, great progress has recently been achieved in the area of various primary processes in photobiology. It was therefore an excellent time to hold the 12th Taniguchi International Symposium, Biophysics Division, on Primary Processes in Photobiology. This volume is the proceedings of that symposium. Among the topics discussed are the femtosecond molecular processes in photosynthetic bacteriochlorophyll and the recently discovered intermediates in the photocycles of rhodopsin (found in the visual pigments of many animals), bacteriorhodopsin (found in the proton-pumping pigments of halobacteria) and retinochrome. New techniques for the measurement of the primary processes are also reported.

Inhalt

I New Experimental Techniques.- Vibrational and Electronic Dephasing Time Measurement with the Use of Temporally Incoherent Light.- II Photosynthesis and Phototransformation.- Energy Gap Law in Electron Transfer Reaction.- Analysis of the Excitation Energy Transfer in Spinach Chloroplasts at Room Temperature..- Photonic Energy Transport in Phycobilin-Chlorophyll System: A Comparative Study with Artificial Multilayer Films..- Calculations of Spectroscopic Properties and Electron Transfer Kinetics of Photosynthetic Bacterial Reaction Centers.- Femtosecond Absorption Studies of the Primary Events in Bacterial Photosynthesis and Light- and Dark-Adapted Bacteriorhodopsin.- The Primary Photochemical Reactions in Systems I and II of Photosynthesis.- Phototransformation Pathway of Phytochrome.- Photochemical Holeburning and Stark Spectroscopy of Photosynthetic Reaction Centers.- III Rhodopsin, Sensory Rhodopsin, Phoborhodopsin, and Retinochrome.- Photochemical Primary Process of Octopus Rhodopsin..- Phototaxis and the Second Sensory Pigment in Halobacterium halobium..- Photocycles of Sensory Rhodopsin.- Flash Photolysis Study on Sensory Rhodopsin and Phoborhodopsin.- Photochemistry of Retinochrome Studied by Nanosecond and Picosecond Spectroscopy..- IV Bacteriorhodopsin.- Determination of Chromophore Structure and Photochemistry in Bacteriorhodopsin with Resonance Raman, NMR, and Chemical Analogues.- On the Nature of the Primary Photochemical Events in Rhodopsin and Bacteriorhodopsin.- Two Kinds of Bacteriorhodopsin Analogues Synthesized from Naphthylretinal.- A New Intermediate in the Photocycle of Bacteriorhodopsin.- Structure Change of Bacteriorhodopsin and the Mechanism of Proton Pump.- Activity of Bacteriorhodopsin in the Presence of a Large pH Gradient.- Picosecond and Nanosecond Spectroscopies of the Photochemical Cycles of Acidified Bacteriorhodopsin.- Structure of Bacteriorhodopsin and Halorhodopsin in Relation to the Pumping function.- Picosecond Intermediates in the Bacteriorhodopsin Photocycle.- The Role of Metal Ions in Bacteriorhodopsin function.- Transient Resonance Raman Spectra of Bacteriorhodopsin and Halorhodopsin.- Index of Contributors.