Enzymes are proteins that act as catalysts in biochemical reactions. ASE is an enzyme that helps to break down starch into simple sugars. CATALYST is an enzyme that helps to speed up chemical reactions. RENNIN is an enzyme found in the stomach that helps to break down milk proteins. PEPSIN is an enzyme found in the stomach that helps to break down proteins. AMYLASE is an enzyme found in saliva that helps to break down carbohydrates. LACTASE is an enzyme found in the small intestine that helps to break down lactose. LIPASE is an enzyme found in the pancreas that helps to break down fats. EREPSIN is an enzyme found in the small intestine that helps to break down proteins. GUANASE is an enzyme found in the small intestine that helps to break down guanine. TRYPSIN is an enzyme found in the pancreas that helps to break down proteins. ESTERASE is an enzyme found in the small intestine that helps to break down esters. PROTEASE is an enzyme found in the small intestine that helps to break down proteins.