Chemical Digestion

• Chemical digestion: where enzymes are used to break down large insoluble substances such as proteins into smaller soluble substances like amino acids so that they can be absorbed.
• Amylase: breaks down starch into maltose, it is produced in the pancreas (but also in the salivary gland)
• Protease: breaks down proteins to peptides (done by pepsin) then into amino acids (done by trypsin). Pepsin comes from the stomach and trypsin comes from the pancreas.
• Lipase: breaks down lipids into fatty acids and glycerol, produced by the pancreas.
• Hydrochloric acid in gastric juice:

  • Denaturing enzymes in harmful microorganisms in food
  • Giving the optimum pH for pepsin activity