1. The Potato Catalase Pre-Lab

2. 100 g of potato were cut into small chunks Potato Catalase Experiment

3. The chunks were put into a blender along with 200mL of water Potato Catalase Experiment

4. The mixture was then pureed at high speed for 1 minute Potato Catalase Experiment

5. The puree was then poured through a wire sieve Potato Catalase Experiment

6. The sieve separates out the foam and the larger chunks of potato Potato Catalase Experiment

7. The foam is then discarded Potato Catalase Experiment

8. Household vinegar and ammonia were used to adjust the pH of the potato extract Potato Catalase Experiment

9. A 25mL graduated cylinder was used to measure out 6mL of potato extract which was then added to each test tube Potato Catalase Experiment To ensure valid results, the graduated cylinder was rinsed out between measurements

10. Drops of vinegar or ammonia were then added to each test tube to obtain the desired pH as shown in the table below Potato Catalase Experiment pH 6pH 7pH 8pH 9 Vinegar2 drops0 drops Ammonia0 drops 2 drops4 drops Distilled Water2 drops4 drops2 drops0 drops

11. 3mL of hydrogen peroxide (3%) were then poured into each of four smaller test tubes Potato Catalase Experiment

12. The 3mL samples of hydrogen peroxide were then added to each test tube and stirred for 2 seconds Potato Catalase Experiment To improve validity, H 2 O 2 was added working left to right, and then each mixture stirred working left to right.

13. After 2 minutes, a marking pen was used to indicate the upper and lower limits of the foam columns. Potato Catalase Experiment To make measurements valid, the marking was also done working left to right.

14. The data table below shows the results of 3 trials. Potato Catalase Experiment Potato Catalases & Hydrogen Peroxide Foam Heights (mm) Trial 1Trial 2Trial 3Average pH 614151314.0 pH 728272827.7 pH 84644 44.7 pH 925232524.3 Three trials helps make the results more reliable. More trials would be even better.

15. Foam Height (mm) as a function of the effect of pH on Catalase Activity Potato Catalase Experiment pH 6 7 8 9 Average Foam Height (mm) 45 40 35 30 25 20 15 10 5 0 44.7mm 24.3mm 14.0mm 27.7mm