Enzymes

• Digestive enzymes


  Convert food into small, soluble molecules that can then be absorbed into the bloodstream
• Digestive enzymes


  • Carbohydrases
  • Proteases
  • Lipases
• Carbohydrases


  Break down carbohydrates into simple sugars
• Products of digestion can be used to build new carbohydrates, lipids, and proteins
• Some of the glucose produced is used in respiration
• Sites of production of digestive enzymes

  • Salivary glands
  • Pancreas
  • Stomach
  • Small intestine
• Digestive enzymes


  • Amylase
  • Proteases
  • Lipases
• Amylase


  Breaks down starch into maltose (a simple sugar)
• Proteases


  Break down proteins into amino acids
• Lipases


  Break down lipids into fatty acids and glycerol
• Effect of pH on enzymes

  • Different enzymes have different optimum pH values
  • Allows enzymes to be adapted to work well in environments with different pH values
  • Parts of the digestive system greatly differ in pH
• Protease in stomach acid

  • Optimum pH is low
• Amylase in neutral saliva


  • Optimum pH is neutral
• As temperature increases


  Rate of enzyme reaction increases
• Optimum temperature


  • This is when the reaction works as fast as possible
• At extremes of pH or very high temperatures, the shape of an enzyme's active site can change</b>
• When the shape of the enzyme's active site is changed, the substrate no longer fits and the enzyme cannot catalyse the reaction - the enzyme has been denatured