factors affecting enzyme action

• 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
• Substrate


  Reactant in a biological chemical reaction
• Products


  Smaller pieces that a substrate is broken into during a reaction
• Enzymes


  • They speed up chemical reactions without being consumed or permanently altered
  • They are specific, only catalyzing reactions where the substrate fits the active site
• Lock and key model

  Original model where substrate had to fit perfectly into active site, like a key in a lock
• Induced fit model


  More realistic model where enzyme changes shape slightly to better accommodate the substrate, like a hand fitting into a rubber glove
• Most chemical reactions in living cells are naturally quite slow
• Increasing temperature


  Can increase reaction rate but causes problems like high energy costs and damage to cells
• Catalyst


  A substance that increases the speed of a chemical reaction without being changed or used up in the process
• Enzymes are a type of biological catalyst