Designing artificial systems with catalytic efficiencies to rival those of natural enzymes is one of the great challenges facing science today. Our current level of understanding fails the basic, practical test - designing and making artificial systems with catalytic efficiencies to rival those of natural enzymes. Chemists and bio-scientists are well aware of this problem, and artificial enzymes have been a hot topic for many years. However, until now, there has been no book devoted specifically to this subject. This is the first book to provide a critical introduction to, and overview of, this exciting area. It is aimed at students and more senior researchers with specialist or general interests in the field. The book starts with a systematic overview of the most important properties of natural enzymes, with special emphasis on mechanisms and efficiency of catalysis. This is followed by a summary of the mechanisms involved in the major classes of reaction they catalyze, and spells out