Carbohydrates : Includes glycogen, starch, sucrose, glucose. Enzymes break big sugars into smaller, simpler sugar so that it's easier to chew. Protein : Amino acids, collagen, keratin. Protease enzymes break down proteins in our food into amino acids. Produces stomach, pancreas, small intestine. Lipids : Fats, oil, glycerol. Lipase breaks down lipids in the diet into fatty acids and glycerol.