Factors affecting enzyme activity

• Low temperature


  Few collisions between the enzyme and substrate

  Not many enzyme-substrate complexes are formed

  The reaction rate is slow
• High temperature


  Molecules that make up the enzyme vibrate

  Hydrogen bonds break

  Enzyme changes shape

  Substrate can no longer bond with the enzyme

  No products can form

  Enzyme activity stops
• Optimum temperature


  optimum collisions occur
• pH


  at levels above and below the optimum, H+ concentration changes the ionic bonds in the protein

  Shape of enzyme and active site change

  Substrate can no longer bind

  No product is formed

  Rate of reaction drops

  
• Substrate concentration


  Increased concentration means that there is a more likely chance of enzymes and the substrate colliding to form enzyme-substrate complexes

  More enzyme-substrate complexes are formed

  Rate of reaction increases until all have bonded and a plateau will then occur