Historical Background, Current Relevance, and Perspectives; Some General Principles; Cobalamins Including Vitamin and Coenzyme 12; Metals at the Centre of Photosynthesis: Magnesium and Manganese; The Dioxygen Molecule, O2: Uptake, Transport, and Storage of an Inorganic Natural Product; Catalysis Through Haemoproteins: Electron Transfer, Oxygen Activation and Metabolism of Inorganic Intermediates; Iron-Sulfur and Other Non-Heme Iron Proteins; Uptake, Transport, and Storage of an Essential Element as Exemplified by Iron; Nickel-Containing Enzymes: The Remarkable Career of a Long Overlooked Biometal; Copper-Containing Proteins: An Alternative to Biological Iron; Biological Functions of the Early Transition Metals: Molybdenum, Tungsten, Vanadium and Chromium; Zinc: Structural and Gene-Regulatory Functions and the Enzymatic Catalysis of Hydrolysis or Condensation Reactions; Unequally Distributed Electrolytes: Function and Transport of Alkali and Alkaline Earth Metal Cations; Catalysis and Regulation of Bioenergetic Processes by the Alkaline Earth Metal Ions Mg2+ and Ca2+; Biomineralization: The Controlled Assembly of Advanced Materials in Biology; Biological Functions of the Non-Metallic Inorganic Elements; The Bioinorganic Chemistry of the Quintessentially Toxic Metals; Biochemical Behaviour of Inorganic Radionuclides: Radiation Risks and Medical Benefits; Chemotherapy with Compounds of Some Non-Essential Elements.