Mittwoch, 12. März, 9:45 Uhr, 1A/B/C
The primary reactions of purple bacterial photosynthesis, i.e. lightharvesting
and electron transfer, take place within two well defined
ring-shaped pigment-protein complexes the peripheral light-harvesting
2 complex, LH2, and the core reaction centre / light-harvesting 1 complex,
RC-LH1. By now it has been established that the spatial arrangement
of the pigments determine to a large extent the spectroscopic
features of these complexes and that collective excitations (Frenkel
excitons) play an important role.
Commonly, the great difficulty to determine the various parameters
that play a role in the description of the electronic structure of lightharvesting
complexes and the process of energy transfer is the fact
that the optical absorption lines are inhomogeneously broadened as
a result of heterogeneity in the ensemble of absorbing pigments. We
circumvent this problem by employing single-molecule spectroscopic
techniques which allows to uncover spectral signatures predicted by
quantum mechanics that would be completely masked by ensemble
averaging in conventional optical experiments. The talk provides an
overview over our work on this topic during the last years.
M. Richter et al. Proc. Natl. Acad. Sci. 104, 16 (2007), 6661-6665
R. J. Cogdell, A. Gall, J. Köhler, Q. Rev. Biophysics 39, (2006), 227-
324
Jürgen Köhler
Experimental Physics IV and Bayreuth Institute for Macromolecular Research (BIMF), University of Bayreuth, D-95440 Bayreuth, Germany