(P4Ab-1) Interaction of Cu²⁺ with the quinone - iron complex and cytochrome B559 in Photosystem II. (Abstract 272)
Kvetoslava Burda^*,1, Jerzy Kruk², Kazimierz Strzalka², Olaf Kruse³, Georg Schmid³, Jan Stanek⁴, ¹ Institute of Nuclear Physics, Krakow, Krakow, Poland² Institute of Biotechnology, Krakow, Krakow, Poland³ Institute of Biology, Bielefeld, Bielefeld, Germany⁴ Institute of Physics, Krakow, Krakow, Poland

(P4Ab-2) Influences of PSII herbicides on the T4 mutant of Blastochloris viridis. (Abstract 273)
Christian Fufezan^{*,1, 2}, Friedel Drepper¹, Hanno Juhnke³, Roy Lancaster³, Alfred Rutherford², Anja Krieger-Liszkay¹, ¹ Institut für Biologie II, Biochemie der Pflanzen, Freiburg, Germany² Section de Bioénergétique, Gif-sur-Yvette, France³ Max Planck Institute of Biophysics, Frankfurt am Main, Germany

(P4Ab-3) EPR characterisation of donor triplet state in Photosystem II with singly reduced primary acceptor Q_A. (Abstract 274)
W. Onno Feikema¹, Peter Gast^*,1, Irina Klenina², Ivan Proskuryakov², ¹ Department of Biophysics, Leiden, The Netherlands² Institute of Basic Biological Problems RAS, Pushchino, Russia

(P4Ab-4) A conformational equilibrium controls the Q_A to Q_B electron transfer in bacterial RCs at low temperature. (Abstract 275)
Nicolas Ginet^*,1, Jérôme Lavergne¹, ¹ LBC - UMR 6191, Saint-Paul-lez-Durance, France

(P4Ab-5) Electron transfer in bacterial reaction centers in the 0 °C to − 60 °C temperature range. (Abstract 276)
Nicolas Ginet^*,1, Jérôme Lavergne¹, ¹ LBC - UMR 6191, Saint-Paul-lez-Durance, France

(P4Ab-6) Origin of kinetic components of millisecond delayed chlorophyll fluorescence. (Abstract 277)
Vassilij Goltsev^*,1, Ivelina Zaharieva¹, Petko Chernev¹, Petar Lambrev², Reto Strasser³, ¹ Department of Biophysics and Radiobiology, Sofia, Bulgaria² Institute of Biophysics, BAS, Sofia, Bulgaria, Sofia, Bulgaria³ Bioenergetics Laboratory, University of Geneva, JUSSY – GENÈVE, Switzerland

(P4Ab-7) A high-field electron paramagnetic resonance study of the primary electron acceptor of Photosystem II generated under cryogenic conditions. (Abstract 278)
Charilaos Goussias^{*,1, 2}, A. William Rutherford¹, Sun Un¹, ¹ Service de Bioenergetique, Gif-sur-Yvette, France² Institute of Materials Science, Athens, Greece

(P4Ab-8) Investigating the energetic of electrons and protons transfer in bacterial photosynthetic reaction center of Rhodobacter sphaeroides. (Abstract 279)
Zhenyu Zhu¹, M. Gunner^*,1, ¹ Physics Department, City College of New York., New York, NY, USA

(P4Ab-9) Intrinsic changes to PSII reaction center properties in mutants of Arabidopsis as probed by thermoluminescence. (Abstract 280)
Luke Hendrickson^*,1, Alexander Ivanov^{1, 2}, Norman Huner², Gunnar Öquist¹, Vaughan Hurry¹, ¹ Umeå Plant Science Center, Umeå, Vasterbotten, Sweden² Biology Department, London, Ontario, Canada

(P4Ab-10) The role of the cytochrome C₅₅₀ in the cyanobacterium Thermosynechoccocus elongatus : A study of redox mutants. (Abstract 281)
Diana Kirilovsky^*,1, Alain Boussac¹, José Maria Ortega³, Mercedes Roncel³, Adjélé Wilson¹, Hervé Bottin¹, Jorge Zurita³, A. Williams Rutherford¹, ¹ Service de Bioenergetique,URA2096 CNRS, DBJC/DSV, Gif sur Yvette, France³ Instituto de Bioquimica Vegetal y Fotosintesis, Sevilla, Spain

(P4Ab-11) Exploring electron-transfer function in photosynthesis by electrostatic-energy computations. (Abstract 282)
Ernst-Walter Knapp^*,1, Hiroshi Ishikita¹, ¹ Free University of Berlin, Berlin, Berlin, Germany

(P4Ab-12) Modeling binding kinetics at the Q_A site in bacterial reaction centers. (Abstract 283)
Jennifer Madeo^*,1, Marilyn Gunner, ¹ Physics Department, USA

(P4Ab-13) A novel protonation pattern for carboxylic acids near Q_B in the asp-l212/glu-l213 mutant reaction center. (Abstract 284)
Eliane Nabedryk^*,1, Jacques Breton¹, Melvin Okamura², Mark Paddock², ¹ Service de Bioénergétique, CEA-Saclay, Gif-sur-Yvette Cedex, France² Department of Physics 0319, La Jolla, USA

(P4Ab-14) The specific rate of Q_A reduction increases as a function of the initial Q_A^- concentration. (Abstract 285)
Szilvia Toth^*,1, Reto Strasser¹, ¹ Laboratory of Bioenergetics, Geneva, Switzerland

(P4Ab-15) System analysis of chlorophyll fluorescence kinetics in chloroplasts: Sub-maximal yield in single turnover excitations and electrical interactions. (Abstract 286)
Wim Vredenberg^*,1, Ondrej Prasil², ¹ Dept. of Plant Physiol. ,Wageningen University and Research, Wageningen, the Netherlands² Laboratoty of Photosynthesis, Acad. of Sciences Czech Republic, Trebon, Czechoslowakia

(P4Ab-16) Characteristics of ubiquinone reduction at the Q_B site following B-branch electron transfer in the Rhodobacter sphaeroides reaction centre. (Abstract 287)
Marion Wakeham^*,1, Jacques Breton^*,2, Paul Fyfe^*,1, Kathryn Norris¹, Eliane Nabedryk², Michael Jones¹, ¹ Department of Biochemistry, Bristol, United Kingdom² Service de Bioénergétique, France

(P4Ab-17) Reconstitution of Q_B function with 1,4-naphthoquinone in bacteria reaction centers with different low potential Q_A's. (Abstract 288)
Xinyu Zhang^*,1, M. Gunner², ¹ The Graduate Center at City University of New York., New York, NY, USA² Physics Department, City College of New York., New York, NY, USA

(P4Ab-18) A functional study of isolated RC-LH1 complexes from R. sphaeroides : excitation transfer, electron transfer and quinone distribution. (Abstract 7289)
Comayras Frédéric^*,1, Jungas Colette¹, Lavergne Jérôme¹, ¹ UMR 6191 CNRS-CEA-Université de la Méditerranée, Saint-Paul-lez-Durance, France