enzymes

• Enzymes are Catalysts Produced by Living Things
• Enzymes speed up reactions by making them happen quicker
• Catalysts


  Substances that increase the rate of a chemical reaction without being consumed or altered themselves
• Enzymes

  • Have special shapes so they can catalyse reactions
  • Are really picky - they usually only catalyse one specific reaction
• For enzymes to work

  The substrate has to fit the enzyme's active site
• Enzymes need the right temperature and pH to work best
• As temperature increases

  The rate of the enzyme-catalysed reaction increases
• If temperature gets too high

  The enzyme becomes denatured and stops working
• Denatured


  When the shape of an enzyme's active site is changed, so the substrate can no longer fit
• All enzymes have an optimum temperature and pH that they work best at
• Pepsin is an enzyme that works best at pH 2 in the acidic conditions of the stomach
• If the pH is too high or too low, it interferes with the bonds holding the enzyme together, changing the shape of the active site and denaturing the enzyme