Enzymes are complex proteins that cause a specific chemical change in other substances, without being changed themselves. For example, they can change starches, proteins, and sugars into substances the body can use. Blood clotting is another example of enzymes at work.
Enzymes are essential to all bodily functions. They are found in the mouth (saliva), stomach (gastric juice), intestines (pancreatic juice, intestinal juice, and intestinal mucosa), blood, and every other organ and cell in the body.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.