This 21 slide PowerPoint gives a clear and understandable explanation of enzymes. The purpose, structure, and function of enzymes and their importance in chemical reactions are shown through descriptions, illustrations, and animations. This presentation could be used to review, introduce, or discuss the process of enzymes. Topics include: enzyme, molecules, energy, building blocks, chemical reactions, catalysts, activation energy, active site, substrate, and life. This power point presentation would be helpful in supporting the objectives in any science class including physical science, general science, Biology, Chemistry.