pH + enzyme activity

• What is the aim of the experiment on amylase enzyme activity?

  To determine starch digestion time at different pH
• What equipment is needed for the amylase enzyme activity experiment?

  • Test tubes
  • Test tube rack
  • Water baths
  • Spotting tiles
  • Measuring cylinder
  • Syringes
  • Glass rod
  • Stopwatch
  • Starch solution
  • Amylase solution
  • Buffered solutions
  • Iodine solution
  • Thermometer
• What is the first step in the method for the experiment?

  Label each well with time and add iodine
• How much buffer solution is added to each test tube?

  2 cm​3​
• What pH range is used for the buffer solutions?

  pH 3.0 to 7.0
• At what temperature should the starch and amylase solutions be equilibrated?

  25​°C
• What should be done immediately after adding starch to the buffer solution?

  Start timing immediately
• How often should the mixture be tested with iodine solution?

  Every 30 seconds
• What indicates that all the starch has been digested?

  When iodine remains brown and does not turn blue-black
• How many times should steps 1-8 be repeated?

  Twice more
• How is the rate of enzyme reaction calculated?

  1/ time taken for iodine to remain brown
• What should be done after calculating the rate of enzyme reaction?

  Repeat for different pH buffer solutions
• What controlled variables must be maintained in the experiment?

  • Temperature
  • Volume and concentration of starch solution
  • Volume and concentration of amylase solution
  • Time interval between testing
• What is a potential source of error in the experiment?

  Time interval may be too long
• What safety precautions should be taken during the experiment?

  Avoid contact with iodine and use goggles
• What should be done if using a Bunsen burner?

  Tie long hair back and wear goggles
• What is the overall process of the experiment on amylase activity?

  1. Prepare buffer solutions at different pH levels.
  2. Mix starch and amylase in buffer.
  3. Measure time for starch digestion using iodine.
  4. Calculate reaction rates and plot against pH.