The Long Wavelength Chlorophylls of Photosystem I

摘要: Summary In cyanobacteria, long wavelength chlorophylls (LWC) are located in the Photosystem I (PS I) core complex, whereas plants and algae they distributed between PS light-harvesting complexes (LHC I). LWC most probably aggregates of (excitonically) coupled chlorophylls, mainly dimers or trimers. The total number is rather small (≤10% chlorophylls). Depending on their location antenna distance from P700, can play a crucial role kinetics energy transfer trapping excitation by charge separation. Energy absorbed transferred uphill to P700 with high efficiency at room temperature, thereby increasing cross-section for absorption red light. involved also dissipation excess energy, thus protecting reaction center. Under physiological conditions, excitations within nearly thermally equilibrated over different spectral forms efficiently trapped via separation When photochemistry center blocked, migrate quenched either + triplet state depending P700.