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Dear Colleagues,<br><br>
The G.R. Harrison Spectroscopy Laboratory and the Department of
Electrical Engineering and Computer Science would like to invite you to
the next seminar in our series on Modern Optics and
Spectroscopy.<br><br>
Date &
Time:<x-tab> </x-tab><x-tab> </x-tab>Tuesday,
October 26, 12 noon - 1 PM<br>
Location:<x-tab> </x-tab><x-tab> </x-tab>Grier
Room (34-401)<br>
Speaker:<x-tab> </x-tab><x-tab> </x-tab><b>Dewey
Holten</b>, Washington University<br>
Title:
<x-tab> </x-tab><x-tab> </x-tab><i>Ultrafast
electron transfer in photosynthetic reaction centers<br><br>
</i>Refreshments will be served following the talk.<br><br>
Abstract<br>
<b>Dewey Holten</b>, Washington University<br>
<i>Ultrafast electron transfer in photosynthetic reaction centers<br>
</i>The primary photochemical steps in the energy conversion process in
photosynthesis occur in pigment-protein complexes called reaction centers
(RCs). In the bacterial RC, membrane-spanning multi-step charge
separation process takes place within 1 ns of with a quantum yield of ~1,
and utilizes only one of two parallel electron-transport chains (the A
branch). We have prepared and investigated a number of mutant RCs
that afford electron transfer down the normally inactive cofactor chain
(the B branch). The penultimate charge-separated state formed via
the B branch differs in charge-recombination pathway and rate compared to
the same state formed via the standard route involving the A
branch. This "memory effect" is being studied to give
insights into functionally significant gating events such as proton
uptake or pigment-protein relaxations that accompany the overall
charge-separation process.<br>
<br><br>
<x-sigsep><p></x-sigsep>
Vinnie Russo * vrusso@mit.edu * Office Manager<br>
MIT; G.R. Harrison Spectroscopy Laboratory<br>
77 Mass. Ave., 6-014 * Cambridge, MA 02139<br>
(v) 617-253-9774 * (f) 617-253-4513</body>
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