Digestive enzymes

• Enzymes


  Catalyze chemical reactions, speed them up
• Enzymes


  • Large protein molecules
  • Have a groove on their surface called the active site
  • The active site is where the substrate attaches
• Substrate


  The molecule that the enzyme breaks down
• Substrate fits into active site


  Enzyme can break down substrate
• Substrate does not fit into active site


  Enzyme cannot break down substrate
• Lock and key theory

  Enzymes are specific, the substrate must fit perfectly into the active site
• Protein digestion


  Proteases break down proteins into amino acids
• Proteins


  • Long chains of chemicals called amino acids
• Starch digestion


  Amylase breaks down starch into simple sugars
• Starch


  A carbohydrate consisting of a chain of glucose molecules
• Lipid digestion


  Lipase breaks down lipids into glycerol and fatty acids
• Lipids


  Molecules consisting of glycerol attached to three fatty acids
• Bile


  Made in the liver, stored in the gallbladder, helps speed up lipid digestion by lipase
• Bile


  Converts large lipid droplets into smaller droplets, increasing surface area for lipase
• Bile


  Alkaline, neutralizes stomach acids, creates alkaline conditions for lipase