enzyme lab
Lab 6.C
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.
Variables:
Independent Variables
Dependent Variable
Controls
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)
Materials:
4 test tubes
Test tube rack
Wax pencil
Small ruler
Buffer solutions of pH 10, 7, 6, and 3
Potato extract
Catechol
Procedure:
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.
Raw Data:
Change in Color of Potato Extract with Different pH Values over Time Based on Color Intensity Scale Initial Observations
5 Minutes
10 Minutes
15 Minutes
20 Minutes
Tube 10
Transparent light red
-
-
-
-
Tube 7
Gold
++
+++
+++
+++
Tube 6
Light gold
+
++
+++
++++
Tube 3
Light yellow
+
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.
Variables:
Independent Variables
Dependent Variable
Controls
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)
Materials:
4 test tubes
Test tube rack
Wax pencil
Small ruler
Buffer solutions of pH 10, 7, 6, and 3
Potato extract
Catechol
Procedure:
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.
Raw Data:
Change in Color of Potato Extract with Different pH Values over Time Based on Color Intensity Scale Initial Observations
5 Minutes
10 Minutes
15 Minutes
20 Minutes
Tube 10
Transparent light red
-
-
-
-
Tube 7
Gold
++
+++
+++
+++
Tube 6
Light gold
+
++
+++
++++
Tube 3
Light yellow
+