Mark one 16 x 150mm test tube as “substrate” and the other as “enzyme”
2. Pour in 0.3mL of 0.1% hydrogen peroxide, 7mL of distilled water and 0.2mL guaicol into the ‘substrate’ tube. This will result in 7.5mL of substrate. Cover the tube with Para film and mix gently
3. Add 0.6mL of pH 10 solution and 1.5mL peroxidase into the ‘enzyme’ tube resulting in a total volume of 7.5mL. Cover and mix gently
4. Incorporate the substrate and the enzyme (with the pH solution) into one 16 x 150mL test tube. Cover, invert tube twice and put tube in the rack. Start timing the reaction promptly.
5. Over a 5-minute period observe any colour changes while being sure to rotate the tube before reading it. Record observations at 1 minute intervals
6. Reference the colour chart on page 156 of the AP Biology Investigation Labs book to compare colour progression.
7. Repeat steps 1- 4 again. After combining the enzyme and the substrate together, quickly and meticulously pipette the solution into the cuvette.
8. Ensure it is completely dry on the outside and insert it into the spectrophotometer with the lines facing side-facing