Enzymes and rate of reaction

• What is the aim for this practical?

  To investigate how temperature or pH affects enzyme activity (e.g., amylase breaking down starch).
• The steps:

  • Heat a water bath to a set temperature (e.g., 20°C, 30°C, 40°C).
  • Add amylase enzyme and starch solution to separate test tubes.
  • Mix them together and start the stopwatch.
  • Every 30 seconds, take a drop and test for starch using iodine (blue-black = starch present).
  • Repeat at different temperatures to find the optimum temperature.
• What is the independent variable?

  Temperature or pH.
• What is the dependent variable?

  Time taken for starch to break down.
• What is the control variable?

  Volume of solutions, enzyme concentration.