Studies of excitation energy transfer within the green alga Chlamydomonas reinhardtii and its mutants at 77 K

The 77 K picosecond fluorescence of intact Chlamydomonas reinhardtii exhibits a 680-nm band (F680) that can be identified with light-harvesting chlorophyll. Analysis of the time and spectral dependence of F680 reveal a forward transfer rate of 1/(15 ps) from this 680-nm species to photosystem II. The possibility of transfer through LHC I, the light-harvesting complex closely associated with photosystem I with a transfer time of 60 to 100 ps, is indicated by analysis of similar data in the 700–720 nm region. Simple kinetic models that account for the time dependence of the emissions F707, F703 and F715 are proposed.Based in part on a thesis submitted in partial fulfillment of the requirements for the Ph.D. Degree, University of Rochester (SL).