Mechanics of energy transfer in light-harvesting antenna proteins: scale-dependent descriptions

Journal club talk by guest speaker Hoda-Hossein Nejad from the Department of Chemistry, UofT, on August 5, 2010

Abstract:
Recent observations of persistent coherence in light-harvesting
antenna proteins pose some interesting questions regarding the role of
quantum effects in photosynthesis: Has nature chosen quantum mechanics as
an strategy for survival? How important are the quantum effects, and on
what scale are these effects significant?

It is plausible to argue that a fully quantum treatment captures the
dynamics of energy transfer on the scale of a few chromophores, but is
both unnecessary and unrealistic for descriptions of long-range energy
transfer between multiple proteins. In this talk,, I will present two
different formulations of the exciton transport problem as applied to the
photosynthetic light-harvesting complex PE545: 1) A fully quantum
description on the scale of a single protein, which takes into account the
interference between pathways leading to a given site. 2) A mixed quantum
classical treatment on the scale of multiple proteins, in which energy
transfer is regarded as a stochastic hop between delocalized eigenstates.