Dresden 2003 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 21: POSTER B
CPP 21.10: Poster
Dienstag, 25. März 2003, 19:00–21:00, ZEU/250
Charge transfer in individual photosynthetic reaction centers — •Alexandra Elli1, Marc Brecht2, Robert Bittl2, Carsten Tietz1, Monika Dueser1, Michael Boersch1, Fedor Jelezko1, and Joerg Wrachtrup1 — 13. Physikalisches Institut, Universitaet Stuttgart, 70550 Stuttgart, Germany — 2Freie Universitaet Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin
In photosynthesis, the light energy absorbed by pigments is not directly converted into the electrochemical potential, but follows several energy transfer steps. Specific pigment-pigment and pigment-protein interactions play a crucial role in the activity of the photosynthetic unit, determining the unidirectional energy pathway towards the special pair. Single molecule technique dealing, with aggregates containing a limited number of pigments is a suitable method to investigate the energy equilibration and the charge transfer dynamics in detail. Under intense illumination, the excited-state population of low-energy chlorophyll molecules is high enough to detect the fluorescence emission of individual reaction center. Since those chlorophylls are located close to the special pair, their emission intensity, and spectral position depends on the state of the primary charge-transfer reaction. These chromophores have been used as sensors of the redox state of the special pair. Fluorescence intensity jumps of single Photosystem I fluorescence related to reversible charge separation have been observed in pre-reduced photosynthetic reaction centers.