Femtosecond transient absorption studies of the light harvesting Chl a/b protein complex of Photosystem II in higher plants

摘要

The first steps of the primary reactions in photosynthesis are the generation of electronically excited states (excitons) by light absorption within pigment protein complexes referred to as light harvesting antenna complexes and rapid exciton migration to the photoactive pigments embedded into the reaction center complex where the transformation into electrochemical free energy takes place. In green algae and higher plants the light harvesting Chl a /b complex associated with Photosystem II (LHC II) serves as the main antenna complex. In this communication we present intensity dependent transient absorption measurements with fs-time resolution in isolated LHC II preparations to address the problem of the interaction of ultrafast exciton migration and exciton-exciton annihilation.