How purple photosynthetic bacteria harvest solar energy

Abstract

This lecture will describe the structure and the function of the light harvesting pigment protein complexes from purple photosynthetic bacteria.  It will illustrate how these membrane proteins had their structure determined.  When a chlorophyll molecule is excited by light, an electron goes from the ground state to the first excited singlet state.  This excited state only lasts for about a nanosecond (10^-9 seconds), because of this the energy transfer reactions in these light harvesting complexes must be faster than a nanosecond, otherwise the excited state will be lost unproductively.  Studies will be described where these energy transfer reactions have been studied with amazing time resolution down to a few femtoseconds (10^-15 seconds).