This course examines the use of metals in biology. Topics include naturally occurring and medicinal ligands; transport, uptake and control of concentration of metal ions; and physical methods of characterization of metal binding sites. The roles of metal ions in nature are discussed, including as structural and signaling elements in proteins, nucleic acids and DNA-binding complexes and proteins; as Lewis-acid centres in enzymes; as carriers of electrons, atoms and groups in redox proteins and enzymes; and as sources of biominerals; as radiopharmaceuticals.