This book gives a broad account of enzymology and aims to put the current knowledge into perspective. The chapters follow a progression from the properties of isolated enzymes to the behaviour of enzymes in increasingly complex systems, leading up to the cell. Included is the discussion on the importance of enzymes in medicine and industry. This book discusses the behaviour of isolated enzymes, dealing in turn with isolation methods, structural characterization, kinetics, catalytic action and control of activity, immobilization methods and various applications of enzymes. The methods for isolation and characterization of enzymes are now well-established procedures, so the rate at which three-dimensional structures and mechanisms are being determined is increasing dramatically. Ultimately it is necessary to know the behaviour of enzymes in living cells. This involves in part a synthesis of the information obtained from the study of isolated enzymes, but it also requires detailed knowledge of the molecular morphology of the cell, which in turn requires methods for making measurements on intact cells. The study and applications of enzymes have assumed increasing importance both in medicine and in industry and a discussion of these aspects is therefore given prime importance. This book will be of immense use to all the UG and PG students of Biotechnology engineering and science students and also to other the sciences students and research scholars.