ELFT HÍRADÓ

[Szommer Peter <szpl AT metal.elte.hu>]

ELTE Fizikai Intézet

                            ORTVAY KOLLOKVIUM
                                
                    2011. május 26., csütörtök, 15 órakor
                Az ELTE Pázmány Péter s. 1/A alatti épületében
                        a földszinti 0.81 előadóban

                Rienk van Grondelle (VU University, Amsterdam)
        "Ultrafast Excitation Energy Transfer and the Mechanism
         of Non-Phtochemical Quenching in Plant Photosynthesis"
		 

Kivonatos ismertetés:
The success of photosynthesis relies on two ultrafast processes: excitation
energy transfer in the light-harvesting antenna followed by charge separation 
in the reaction center. LHCII, the peripheral light-harvesting complex of 
Photosystem II, plays a major role. At the same time, the same light-harvesting
system can be 'switched' into a quenching state, which effectively protects 
the reaction center of Photosystem II from over-excitation and photodamage. In 
this talk I will demonstrate how LHCII collects and transfers excitation energy.
Using single molecule spectroscopy we have discovered how LHCII can switch 
between this light-harvesting state, a quenched state and a red-shifted state.
We show that the switching properties between the light-harvesting state and 
the quenched state depend strongly on the environmental conditions, where the 
quenched state is favoured under 'NPQ-like' conditions. It is argued that this 
is the mechanism of non-photochemical quenching in plants.