This textbook covers most of the important enzymatic reactions and related catalytic bioorganic reactions using a new didactical concept: Together with the specific enzyme class performing a specific transformation (e.g. aldolases), also corresponding catalytic reactions are described. From catalytic antibodies over organometallic catalysts to metal complexes all important catalyst classes are included. <br> This will provide the reader an unique overview, especially emphasizing relationships as well as fundamental differences between enzymes and other bioorganic catalysts.