Dedication/Perspective: A tribute to Jerry Babcock -- to Photosystem II -- Distal and Extrinsic Photosystem II Antennas -- The CP47 and CP43 Core Antenna Components -- The D1 and D2 Core Proteins -- The Extrinsic Proteins of Photosystem II -- The Low Molecular Weight Proteins of Photosystem II -- Primary Electron Transfer -- The Iron-Quinone Acceptor Complex -- The Redox-Active Tyrosines YZ and YD -- The Catalytic Manganese Cluster: Organization of the Metal Ions -- The Catalytic Manganese Cluster: Protein Ligation -- The Catalytic Manganese Cluster: Implications from Spectroscopy -- The Calcium and Chloride Cofactors -- Bicarbonate Interactions -- Side-Path Electron Donors: Cytochrome b559, Chlorophyll Z and ?-Carotene -- Molecular Analysis by Vibrational Spectroscopy -- Configuration of Electron Transfer Components Studied by EPR Spectroscopy -- Structural Analysis of the Photosystem II Core/Antenna Holocomplex by Electron Microscopy -- Photosystem II: Structural Elements, the First 3D Crystal Structure and Functional Implications -- 3D Crystal Structure of the Photosystem II Core -- Refined X-Ray Structure of Photosystem II and Its Implications -- Energy Trapping and Equilibration: A Balance of Regulation and Efficiency -- The Role of Carotenoids in Energy Quenching -- Flash-Induced Oxygen Evolution and Other Oscillatory Processes -- Mechanism of Photosynthetic Oxygen Production -- Photo-Assembly of the Catalytic Manganese Cluster -- Photoinactivation and Mechanisms of Recovery -- Transcriptional and Translational Regulation of Photosystem II Gene Expression -- Protein Transport and Post-translational Processing in Photosystem II Biosynthesis and Homeostasis -- The Origin and Evolution of Photosynthetic Oxygen Production -- Mechanistic Comparisons Between Photosystem II and Cytochrome c Oxidase -- Mimicking the Properties of Photosystem II in Bacterial Reaction Centers -- De Novo Protein Design in Respiration and Photosynthesis -- Understanding Photosystem II Function by Artificial Photosynthesis. Dedicated to the memory of one of the early pioneers in this field of research, Professor Gerald T. Babcock, the 34 inclusive chapters of the present volume cover all major aspects of the molecular biology, biochemistry, biophysics and physiology of Photosystem II. The chapters were variously authored by a total of 75 scientific experts from leading research centers in Europe, North America, Asia and Australia, making the book a truly international effort. The book is divided into several parts which detail the protein constituents, functional sites, tertiary structure, molecular dynamics and mechanisms of subunit assembly and homeostasis. The book ends with a comparison of Photosystem II structure and function with other related enzymes and bio-mimetic systems. Since the unique water-splitting chemistry catalyzed by Photosystem II leads to the production of pure oxygen gas and the potential for making hydrogen gas, a primary goal of this book is to provide a molecular guide to future protein engineers and bio-mimetic chemists in the development of appropriate biocatalysts for the generation of clean, renewable energy from sunlight and water.