Digestion is a complex process that requires several components to break down food into smaller molecules. BILE, an ACID produced by the liver, helps to emulsify fats and provide lubrication for the digestive tract. Enzymes are proteins that catalyze chemical reactions, and SALIVA contains enzymes that help to break down carbohydrates. ACID is also necessary for digestion, as it helps to activate certain enzymes. PEPSIN is an ENZYME found in the stomach that helps to break down proteins. Peristalsis is a series of muscular contractions that move food through the digestive tract. All of these components work together to aid in the digestion of food.