Hypothesis: If enzyme activity is affected by the pH of a solution, then the enzymes will experience the greatest activity at a pH of 6.
Four different pH values (10, 7, 6, and 3)
Change in color of the solution
The amount of potato extract, pH solution, and catechol used (1 cm +/- .1cm)
Size of the test tubes
Amount of time allowed for the catechol to sit with the potato extract and pH solution (20 minutes with 5 minute intervals for observation)
4 test tubes
Test tube rack
Buffer solutions of pH 10, 7, 6, and 3
1. Using the small ruler and the wax pencil, three markings are made on 3 test tubes. These markings should be at 1, 2, and 3 cm from the bottom of the tube. These tubes are then numbered by their pH values: 10, 7, 6, and 3.
2. One potato is chopped into small pieces and placed into a blender.
3. 125mL of distilled water is added to the potato.
4. This solution is blended on high just long enough to break open the cells, approximately 5 seconds.
5. This is then strained through 3 layers of cheese cloth into a beaker and kept cold in order to help prevent oxidation of the enzymes.
6. Each tube is filled up to the 1 cm mark with the solution matching the pH written on it.
7. Each test tube is then filled up to the 2 cm mark with potato extract and mixed.
8. Next, each tube is filled to the 3 cm mark with catechol and mixed well.
9. Any color changes are observed and documented using a plus and minus scale at 5 minute intervals for a total of 20 minutes.
Change in Color of Potato Extract with Different pH Values over Time Based on Color Intensity Scale Initial Observations
Transparent light red