Sökning: "proton-coupled energy transfer"

Visar resultat 6 - 10 av 12 avhandlingar innehållade orden proton-coupled energy transfer.

  1. 6. Trapping Tyrosine Z : Exploring the Relay between Photochemistry and Water Oxidation in Photosystem II

    Författare :Johannes Sjöholm; Stenbjörn Styring; Fikret Mamedov; A. William Rutherford; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Photosystem II; Tyrosine Z; EPR; proton-coupled electron transfer; hydrogen bond; pH;

    Sammanfattning : Photosystem II is unique! It remains the only enzyme that can oxidize water using light as energy input. Water oxidation in photosystem II is catalyzed by the CaMn4 cluster. The electrons extracted from the CaMn4 cluster are transferred to P680+ via the tyrosine residue D1-Tyr161 (YZ). LÄS MER

  3. 7. Transmembrane proton transfer in biological systems : an investigation of bacterial and archaeal haem-copper oxidases

    Författare :Gwen Gilderson; Ólöf Einarsdóttir; Stockholms universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Biochemistry; Biokemi; biokemi; Biochemistry;

    Sammanfattning : Haem-copper oxidases are membrane-bound protein complexes that catalyse the reduction of dioxygen to water in the respiratory chain. These enzyme complexes are molecular machines that couple the free energy released from this reaction to pump protons across the membrane. LÄS MER

  4. 8. Hydrogen Bonded Phenols as Models for Redox-Active Tyrosines in Enzymes

    Författare :Josefin Utas; Björn Åkermark; Helena Grennberg; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; electron transfer; photosystem II; radicals; imidazole; hydrogen bonding; Organic chemistry; Organisk kemi;

    Sammanfattning : This thesis deals with the impact of hydrogen bonding on the properties of phenols. The possibility for tyrosine to form hydrogen bonds to other amino acids has been found to be important for its function as an electron transfer mediator in a number of important redox enzymes. LÄS MER

  5. 9. Electrochemical Reactions of Quinones at Conducting Polymer Electrodes

    Författare :Canyan Che; Xavier Crispin; Mikhail Vagin; Magnus Jonsson; Viktor Gueskine; Mieczyslaw Lapkowski; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Proton-coupled multielectron transfer reactions are of great abundance in Nature. In particular, two-proton-two-electron transfers in quinone/hydroquinone redox couples are behind oxidative phosphorylation (ADP-to-ATP) and photosystem II. LÄS MER

  7. 10. Development and Mechanistic Studies of Molecularly Defined Water Oxidation Catalysts : Catalysts for a Green and Sustainable Future

    Författare :Markus Kärkäs; Björn Åkermark; Jean-François Nierengarten; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; artificial photosynthesis; water oxidation; photochemistry; electrochemistry; organisk kemi; Organic Chemistry;

    Sammanfattning : This thesis deals with the development of complexes that are active catalysts for H2O oxidation. Promoting proton-coupled electron transfer has been a highly important feature in the development of these catalysts. LÄS MER