Practical B3 - Effect of temperature on the action of an enzyme


  1. Set up water baths at various temperatures (e.g. 0°C, 20°C, 40°C, 60°C and 80°C).
  2. Add starch solution to 5 test tubes.
  3. Add amylase solution to another 5 test tubes.
  4. Place one starch and one amylase test tube into each water bath for 5 minutes - to allow the enzyme and substrate to reach the desired temperature.
  5. Place 1 drop of iodine into each dimple on a spotting tile.
  6. Add the amylase to the starch in the 0°C water bath.
  7. Start the timer.
  8. Every minute remove a sample of the starch-amylase solution and add it to a drop of iodine on the spotting tile.
  9. Repeat step 8 until the iodine no longer changes colour - meaning that there is no starch present, in other words the amylase has broken all starch down.
  10. Repeat steps 6-9 for each of the temperatures.
  11. Record results.
  12. Draw a graph to show the time taken for starch to be digested at different temperatures.