2:40 PM
() Chair's Introduction. (Abstract )

2:50 PM
(S4Ab-1) Coupling of Light-Induced Electron Transfer to Proton Uptake in Photosynthesis. (Abstract 71)
André Remy^*,1, Klaus Gerwert¹, ¹ Lehrstuhl für Biophysik, Ruhr-Universität Bochum, Postfach 102148, Bochum, Germany

3:20 PM
(S4Ab-2) Electron transfer coupled protein relaxation in reaction centers of RB. sphaeroides. (Abstract 72)
Maria Kozlova^*,1, Dmitry Cherepanov¹, Laura Baciou², Pierre Sebban², Armen Mulkidjanian¹, ¹ Universität Osnabrück, Abt. Biophysik/FB Biologie, Osnabrück, Germany² Laboratoire de Chimie Physique, Bat. 350, University Paris-IX, Orsay, France

3:40 PM
(S4Ab-3) Redox potentials of quinones controlled by hydrogen bonding pattern in photosystem II. (Abstract 73)
Hiroshi Ishikita^*,1, Ernst-Walter Knapp¹, ¹ Free University of Berlin, Institute of Chemistry, Takustrasse 6, Berlin, Germany

4:00 PM
(S4Ab-4) Q_B^-. states trapped by B-branch electron transfer in reaction centers from Rhodobacter sphaeroides investigated by EPR and ENDOR. (Abstract 74)
Mark Paddock^*,1, Roger Isaacson¹, Marco Flores¹, Charlene Chang¹, Edward Abresch¹, George Feher¹, Melvin Okamura¹, ¹ Department of Physics 0319, La Jolla, California, USA

4:20 PM
(S4Ab-5) Formation of a ubiquinone anion via B-branch electron transfer in the reaction centre from Rhodobacter sphaeroides.. (Abstract 75)
Marion Wakeham ¹, Eliane Nabedryk², Dmitrij Frolov³, Bruno Robert⁴, Jane Potter¹, Rienk van Grondelle³, Jacques Breton², Michael Jones^*,1, ¹ Department of Biochemistry, School of Medical Sciences, Bristol, United Kingdom² Service de Bioénergétique, France³ Department of Physics and Astronomy, Amsterdam, The Netherlands⁴ Section de Biophysique des Fonctions Membranaires, France