The composition, structure and reactivity of enzymes are studied. The enhancement of reactivity in enzymic reactions, from both a kinetic and mechanistic viewpoint, and methods of enzyme inhibition are discussed. The structure and function of DNA is then examined. Topics covered include replication, transcription, translation, and gene regulation. The second part of the course covers general aspects of the inorganic chemistry of biological systems, in particular the roles of metal ions in biological processes, e.g.. the function of iron in haemoglobin and myoglobin is elaborated. Techniques discussed include X-ray structure analysis, EXAFS, electron paramagnetic resonance (EPR) and luminescence spectroscopy.