Digestive enzymes

• Enzymes catalyse chemical reactions
• Enzymes have large protein molecules and have a groove on their surface called the active site. The active site is where the substrate attaches to. The enzymes break the substrate into the products.

  
• Enzymes are specific. The substrate must fit perfectly into the active site.
• Enzymes are made of proteins
• Proteins are broken down by protease enzymes.
• Protease enzymes are found in the stomach, pancreas and small intestine.
• Proteins are long chains of amino acids. Protease converts the protein back into the original amino acids. Then when they are absorbed by body cells they are joined together in a different order to make human proteins.

  
• Starch is digested by amylase.
• Amylase is found in the saliva and pancreatic fluid.
• Starch consists of a chain of glucose molecules. They are broken down by carbohydrases. When starch is digested they produce simple sugars.
• A lipid molecule consists of a molecule of glycerol, attached to 3 molecules of fatty acids.
• Lipids are digested by lipase.
• Lipases is found in the pancreatic fluid and in the small intestine.
• When lipids are digested by lipase they produce fatty acids and glycerol.
• Bile stored in the gall bladder.
• Bile is made in the liver.
• Bile converts large lipids to small lipids by emulsifying the lipids.
• Emulsifying


  the breakdown of fat molecules into tiny droplets that are water-soluble. Increasing the surface area which increases the rate of the break down of molecules.