enzymes

• Enzymes


  Catalysts made by living organisms
• Enzymes


  • They are large proteins made up of long chains of amino acids
  • They can fold into different shapes, each shape being a unique enzyme that catalyzes a particular chemical reaction
• How enzymes work


  1. Enzyme has an active site with a unique shape complementary to the substrate

  2. Substrate binds to active site

  3. Enzyme catalyzes the reaction

  4. Products are released
• Catalyst


  A substance that increases the speed of a chemical reaction without being changed or used up in the process
• Most chemical reactions are naturally quite slow


  Enzymes speed up the process
• Increasing temperature


  Can damage cells and speed up unwanted reactions
• Lock and key model


  Original model where substrate has to fit perfectly into the active site of the enzyme
• Induced fit model


  More realistic model where the enzyme changes shape slightly to better fit the substrate
• The active site of an enzyme is complementary to the substrate
• The induced fit model is like putting your hand into a rubber glove - the glove molds around your hand to become a perfect fit