Photosynthetic purple bacteria employ an antenna system to absorb sunlight and transfer electronic excitation to a centrally located protein, the photosynthetic reaction center. The antenna system employs for this purpose a hierarchy of circular bacteriochlorophyll aggregates. For the case of a particular light harvesting protein with known structure, one- and two-exciton spectra of its circular bacteriochlorophyll aggregate are determined by means of an effective Hamiltonian description. A detailed geometric model for the complete antenna system of the purple bacterium Rhodobacter sphaeroides is provided by molecular modelling and its bacteriochlorophyll aggregates are investigated, employing also an effective Hamiltonian. Transfer times within the complete antenna system and from the antennae to the reaction center are calculatec.
- Circular aggregates
- Light-harvesting complexes
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Atomic and Molecular Physics, and Optics