Molecular and Cellular Enzymology addresses not only experienced enzymologists but also students, teachers and academic and industrial researchers who are confronted with enzymological problems during their fundamental or applied research. In this field is an urgent need for training in order to meet the requirements of both research and industrial endeavours. This book consists of several levels. Practical aspects and elementary explanations are given for the benefit of non-specialists’ and students’ understanding. In order to facilitate the task of students, two typographies have been adopted. The main text corresponds to basic knowledge, whereas text in a smaller font provides more specialised information. Specialists will also find topics more deeply expounded with the principal bibliographic references cited. The bibliography, however, is not exhaustive; the choice includes general books and review articles as well as some specialised articles. In this book, for the first time, the different molecular and cellular aspects of enzymology are presented together. Until now, there has been no book available in which these different aspects are treated in the same volume. In addition, besides the theoretical developments, this book provides a wealth of practical information for experimentalists. Jeannine Yon-Kahn, Emeritus Director of Research at the CNRS, created and directed the Laboratory of Physicochemical Enzymology at the University of Paris-Sud (Orsay, France). She was Director of Doctoral Studies in the Structure, Function and Engineering of Proteins. She was a member of several Scientific Committees (including CNRS and INRA) and is a foreign member of the Brazilian Academy of Sciences. Guy Hervé, Emeritus Director of Research at the CNRS, was Director of the CNRS Institute of Enzymology and of one of the Biochemistry Laboratories at the Pierre and Marie Curie University in Paris. He was also Director of the Doctoral School of Molecular and Cellular Biology at that same university and President of the French Biophysical Society.