Chemical Digestion (Cambridge (CIE) IGCSE Biology): Revision Note

Chemical digestion

• Chemical digestion is the breakdown of large insoluble molecules into small soluble molecules

  • E.g. starch (a large insoluble molecule) is broken down into simple sugars (small, soluble molecules) by the enzyme amylase (opens in a new tab)

• Chemical digestion is required because large insoluble molecules are unable to be absorbed through the wall of the small intestine

• Small soluble molecules produced by chemical digestion are easily absorbed into the surrounding capillaries in the wall of the small intestine

• Enzymes are required for chemical digestion to take place