DIGESTIVE SYSTEM/ ENZYMES (Organisation)

• The digestive system is an example of an organ system in which several organs work together to digest and absorb food
• Enzymes


  They catalyse specific reactions in living organisms due to the shape of their active site
• Lock and key theory

  A simplified model to explain enzyme action
• Digestive enzymes


  • Carbohydrases
  • Proteases
  • Lipases
• Carbohydrases


  Break down carbohydrates to simple sugars
• Amylase


  A carbohydrase which breaks down starch
• Proteases


  Break down proteins to amino acids
• Lipases


  Break down lipids (fats) to glycerol and fatty acids
• The products of digestion are used to build new molecules
• Students should be able to use the 'lock and key theory' as a simplified model to explain enzyme action
• Students should be able to recall the sites of production and the action of amylase, proteases and lipases
• Students should be able to understand simple word equations but no chemical symbol equations are required
• Students should be able to relate knowledge of enzymes to Metabolism
• Students should be able to describe the nature of enzyme molecules and relate their activity to temperature and pH changes
• Students should be able to carry out rate calculations for chemical reactions
• Digestive enzymes convert food into small soluble molecules that can be absorbed into the bloodstream
• MS 1a, 1c: Students should be able to develop an understanding of size and scale in relation to cells, tissues, organs and systems