[5] Techniques for studying light-induced paramagnetism in photosynthetic materials by means of electron paramagnetic resonance spectroscopy

摘要: Publisher Summary This chapter discusses the methods relevant to performing electron paramagnetic resonance (EPR) experiments on light-induced resonances in photosynthetic materials. The experimental aspects of working with aqueous suspensions necessarily complex systems: algae, chloroplasts, subchloroplast fractions, bacteria, chromatophores, and “reaction-center” preparations are presented. at ambient temperature emphasized. Techniques for quantitative qualitative determination information content EPR signals outlined. One the, single signal corresponding I plants, is a property reaction center, as such evidence first chemical act following absorption photon. There two main advantages spectrometer detector effects any photobiological process. First, energy required induce allowed transitions between quantized magnetic levels unpaired electrons responsible sufficiently low that organism totally unaffected by scanning microwave radiation, which has wavelength order 3, cm. Second, substances bulk chlorophyll, do not become when illuminated, transparent spectrometer.