The present book might be regarded as a sequel to my previous work, Bioinorganic Chemistry: An Introduction (Allyn and Bacon, 1977). The latter is essentially a collection of chemical and physical data pertinent to an understanding of the biological functions of the various elements and the proteins dependent on them. The ten years since its publication have seen an enormous increase in research activity in this area, hence of research papers. A number of monographs and review series on specific topics have also appeared, including the volumes in the series of which the present volume is a part. Nevertheless, a gap has developed between the flood of information available at a detailed level (papers and reviews) and a general description of the underlying principles of biofunctions of the elements as presently conceived. It is hoped that this book will help bridge this gap and at the same time provide an overview of the entire Biochemistry of the Elements series. Specifically, the work attempts to focus on "why" questions, especially, "Why has an element been chosen by organisms for a specific biofunction?" and "Why does an element behave the way it does in biological systems?" It therefore complements my 1977 book and, together with Laboratory Introduction to Bio-Inorganic Chemistry (E. -I. Ochiai and D. R. Williams, Macmillan, 1979), completes a trilogy on the topic of bioinorganic chemistry. This book consists of five parts. Two chapters constitute Part I.

I. Overview.- 1. Global Aspects of the Biochemistry of the Elements.- 2. Some Basic Principles of the Biochemistry of the Elements.- II. Chemical Principles of the Biochemistry of the Elements.- 3. Oxidation-Reduction and Enzymes and Proteins.- 4. Enzymes and Proteins in the Reactions of Oxygen and Oxygen Derivatives.- 5. Enzymes in Acid-Base Reactions.- 6. Structural Functions.- 7. Miscellaneous Topics.- III. Chemical Principles of Transport of the Elements.- 8. Chemistry of Uptake-Thermodynamic and Kinetic Factors in Passive Transport.- 9. lonophores, Channels, Transfer Proteins, and Storage Proteins.- 10. Active Transport.- IV. Biological Aspects I-Metabolism of the Elements.- 11. Metabolism of Elements by Bacteria, Fungi, Algae, and Plants.- 12. Metabolism of Elements in Mammals and Vertebrates.- V. Biological Aspects II-Toxicity of and Defense against the Elements.- 13. Oxygen-Its Toxicity and Defense against It.- 14. Toxicity of Heavy Metals.- 15. Toxicity of Other Elements.- References.