Enzymes cgp

• Enzymes

  Catalysts produced by living things
• Active site


  The part of the enzyme where it joins on to its substrate to catalyse the reaction
• Enzymes


  • They only work with one substrate
  • They have a high specificity for their substrate
  • This is because the substrate has to fit into the active site of the enzyme
• If the substrate's shape doesn't match the active site's shape

  The reaction won't be catalysed
• Lock and key mechanism

  The substrate fits into the enzyme's active site just like a key fits into a lock
• As temperature increases

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

  Bonds holding the enzyme together break, changing the shape of the active site, so the substrate won't fit anymore - the enzyme is denatured
• Optimum temperature


  The temperature at which an enzyme works best
• If 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
• Optimum pH


  The pH at which an enzyme works best
• Enzymes that break down different molecules


  • Carbohydrases (e.g. amylase) break down carbohydrates
  • Proteases convert proteins into amino acids
  • Lipases convert lipids into glycerol and fatty acids
• Diffusion

  The net movement of particles from an area of high concentration to an area of low concentration
• Osmosis

  The net movement of water molecules from a high water potential to a region of low water potential through a partially permeable membrane
• Active transport

  The movement of particles from an area of low to an area of high concentration (using energy transferred during respiration)
• Diffusion

  The movement of particles from an area of high concentration to an area of low concentration