Supervisor: Prof. Benedetta Mennucci

Title: Simulation of energy transfer processes in light-harvesting photosynthetic systems

Abstract: In higher plants, cyanobacterias and algae cytoplasm there are structures called chloroplasts which are responsible for the photosynthesis processes. The phospholipid membrane of those organelles, called thylakoid, has an electron transportation role in the photosynthesis process. In the thylakoid membrane there are large protein photosystems composed by a core and light-harvesting complexes which contain pigments responsible to absorb light radiation. Those complexes act as antennas absorbing solar light and transferring it, as the form of excitation energy, to the core where there is a reaction center. Around the core of the photosystems there are several complexes that constitute the peripheral antenna system. The major antenna complex is the LHCII which is surrounded by three subunits: CP29, CP26 and CP24. The CP29 is the largest subunit of the peripheral antenna system and is the study object of this research. The position and the great amount of chlorophylls molecules in this complex suggest that it has a light-harvesting role. It is composed also by 3 carotenoids molecules which indicate that CP29 complex can act also as a photoprotector preventing the photodamage processes in those organisms. In general terms, the goal of this research is study the exited energy transfer (EET) between the cofactors present in the CP29 complex taking into account their interaction with the environment. In this work, the CP29 system is studied using a computational strategy QM/classical developed during this PhD period.