Photosynthesis I

As editor of the two-part Volume V on photosynthesis in RUHLAND'S Encyclopedia, the forerunner of this series published in 1960, I have been approached by the editors of the present volume to provide a short preface. The justification for following this suggestion lies in the great changes which have been taking place in biology in the two decades between these publications, changes which are reflected in the new editorial plan. Twenty years ago it appeared convenient and formally easy to consider photo­ synthesis as a clearly separated field of research, which could be dealt with under two major headings: one presenting primarily photochemical and biochemical prin­ ciples, the other physiological and environmental studies. Such a partition, however, as far as aims and opinions of the authors were concerned, resulted in a rather heterogeneous volume. Today, the tendency in experimental biology is towards a merger of previously distinct disciplines. Biochemists and biophysicists have developed their methods to such an extent that, over and above the analysis of individual reaction sequences, work on the manifold interrelationships among cellular activities has become in­ creasingly possible. Joining them in growing numbers are the physiologists and ecologists with their wealth of information on activity changes in vivo and on the variability and efficiency of the organisms concerned. Furthermore, biochemists, biophysicists and physiologists also now share a lively interest in ultrastructure research, the results and implications of which, through continually improving methodology, have generated important stimuli for the work in the field of cell function.

Contenu

I. History.- Photosynthesis 1950-75: Changing Concepts and Perspectives.- A. Introduction.- B. Photosynthesis Research at Midcentury.- C. Research Past Midcentury: Some Major Advances.- D. CO2 Assimilation: Experiments with Whole Cells.- E. Evidence for CO2 Assimilation by Isolated Chloroplasts.- F. Investigations of Light Reactions of Photosynthesis: Experimental Advantages of Chloroplasts Over Whole Cells.- G. Discovery of Photosynthetic Phosphorylation.- H. The Concept of a Light-Induced Electron Flow.- I. Noncyclic Photophosphorylation.- J. Role of Cyclic Photophosphorylation: Early Views.- K. Physical Separation of Light and Dark Phases of Photosynthesis in Chloroplasts.- L. Ferredoxins in Chloroplasts and Bacteria.- M. Role of Ferredoxin in Noncyclic Photophosphorylation.- N. Ferredoxin as the Physiological Catalyst of Cyclic Photophosphorylation.- O. Stoichiometry and Regulation of Ferredoxin-Catalyzed Photophosphorylations.- P. Other Ferredoxin-Dependent Reactions in Photosynthetic Cells.- Q. Multiple Ferredoxins: Soluble and Bound.- R. Photosynthetic Electron Carriers.- S. Two Photosystems in Plant Photosynthesis: Origins of a Concept.- T. Two Photosystems: Facts, Hypotheses, and Dogma.- U. Concluding Remarks.- References.- II. Electron Transport.- 1. General 1 a. Physical Aspects of Light Harvesting, Electron Transport and Electrochemical Potential Generation in Photosynthesis of Green Plants.- A. Introduction.- B. Antennae.- I. Physically Different Types of Chlorophylls in Chloroplasts.- II. Resonant Energy Transfer.- III. Distinctive Properties of Antennae Systems I and II.- IV. Size and Interaction of the Antennae Systems.- V. Protective Reactions.- VI. Structure.- C. Electron Transport.- I. Photochemical Reactions.- II. Non-Photochemical Components.- D. Electrochemical Potential Generation.- I. The Generation of an Electric Potential.- II. Proton Translocation.- References.- 1b. Electron Transport in Chloroplasts.- A. General.- B. Photosystem II.- I. The Oxidizing Side of PS II.- II. The Reaction Center Complex of PS II.- III. The Reducing Side of PS II.- C. Photosystem I.- I. The Primary Acceptor of PS I.- II. The Reducing Side of PS I.- III. The Oxidizing Side of PS I.- References.- 2. Porphyrins, Chlorophyll, and Photosynthesis.- A. Introduction.- B. Structure.- C. Function.- D. Evolution.- E. Summary.- References.- 3. Light Conversion Efficiency in Photosynthesis.- A. Basic Principles.- B. The Maximum Efficiency of Photosynthesis: Quantum Yields Under Optimum Conditions.- C. ATP Production and Utilization.- D. Quantum Yields of Growing Cells and Photosynthetic Productivity Under Natural Conditions.- References.- 4. P-700.- A. General.- B. Optical Properties.- C. Oxidation-Reduction.- D. Models.- E. Localization of P-700.- F. Orientation of P-700.- G. Oxidation of P-700.- H. Reduction of P-700.- References.- 5. Chlorophyll Fluorescence: A Probe for Electron Transfer and Energy Transfer.- A. Introduction.- B. Fluorescence Yield and Electron Transport.- I. A (Q).- II. C-550.- III. P-680.- IV. The Back-Reaction.- C. The Photochemical Model.- I. Photosystem II.- II. Photosystem I.- III. The Photochemical Apparatus.- IV. Energy Distribution Between PS I and PS II.- D. Appendix.- References.- 6. Electron Paramagnetic Resonance Spectroscopy.- A. Introduction.- B. EPR Techniques.- C. EPR Studies in Photosynthesis.- I. Bacterial Photosynthesis.- II. Signals in Photosystem II (PS II).- III. Signals in Photosystem I (PS I).- IV. Spin Labels.- D. Conclusion.- References.- 7. Primary Electron Acceptors.- A. Chloroplast Photosystem I.- I. Background.- II. Electron Paramagnetic Resonance (EPR) Studies of Bound Iron-Sulfur Proteins.- III. Flash Kinetic Spectroscopy of P-430.- IV. Relationship of P-430 to Bound Iron-Sulfur Protein.- B. Chloroplast Photosystem II.- I. X-320.- II. C-550.- III. On the Chemical Identity of the Photosystem II Primary Electron Acceptor.- References.- 8. Oxygen Evolution and Manganese.- A. Introduction.- B. Photosystem II.- C. Kinetic Model of O2 Production.- D. Interconversion of S-States in the Dark.- E. Turnover Reactions of Photosystem II.- F. Phenomena Related to the S-States.- G. Chemical Treatments that Reversibly Affect the O2 Evolving Site.- H. Localization of the Oxygen-Evolving Site.- References.- 9. Ferredoxin.- A. Introduction.- B. Extraction and Purification.- C. Assay.- D. Occurrence and Biosynthesis.- E. Properties.- F. Nature of the Active Center.- G. Stability.- H. Biological Function.- I. Immunological Studies.- J. Homology in the Primary Structures.- References.- 10. Flavodoxin.- A. Biological Properties.- B. Chemical Properties.- References.- 11. Flavoproteins.- A. Introduction.- B. Isolation and Physico-Chemical Properties of the Chloroplast Flavoprotein, Ferre doxin-NADP+ Reductase,.- C. Kinetic Properties of Ferredoxin-NADP+ Reductase.- D. Multiple Forms of the Chloroplast Flavoprotein.- References.- 12. Cytochromes.- A. Introduction.- B. Isolated Higher Plant Cytochromes.- C. Isolated Algal Cytochromes.- D. Cytochrome Function in Electron Transport.- References.- 13. Plastoquinone.- A. Introduction and Properties.- B. Experiments with Extracted Chloroplasts.- C. Reactions of Endogenous Plastoquinone as Secondary Electron Acceptor.- D. Identity of the Primary Electron Acceptor of Photosystem II.- E. Specific Inhibitors of Plastoquinone.- References.- 14. Plastocyanin.- A. Distribution and Localization.- B. Extraction and Purification.- C. Molecular Properties.- D. Function in Photosynthetic Electron Transport System.- References.- 15. Artificial Acceptors and Donors.- A. Introduction.- B. General Aspects.- C. Electron Acceptors.- D. Electron Donors.- E. Compounds Accepting and Donating Electrons-Cyclic Electron Transport and Bypasses.- F. The Topography of the Chloroplast Membrane and Artificial Energy Conservation 261 References.- References.- 16. Inhibitors of Electron Transport.- A. Introduction.- B. Description of Inhibitors.- I. Inhibitors that Act on Water-Oxidizing Side of Photosystem II.- II. Inhibitors that Block Exit of Electrons from Photosystem II.- III. Plastoquinone Antagonists.- IV. Inhibitors of Electron Transfer Between Plastoquinone and cytochrome f.- V. Inhibitors of Plastocyanin.- VI. Inhibitors of Reactio…