Enzyme Lab Activity
By Amir Ziaei
Identification of Variables
The dependent variables are enzyme concentration and temperature.
The constant is what the enzymes are composed of.
If the temperature increases, then the rate of reaction will increase at first, then decrease.
-Vernier Gas Pressure Sensor
-rubber stopper assembly
-10 mL graduated cylinder
-250 mL beaker of water
-3% Hydrogen Peroxide
-styrofoam cup to use as a water bath
-four 18x150 mm test tubes
-pH buffers (4, 7, 10)
-test tube rack
-four dispensable pipettes
1. wear goggles
2. Connect plastic tubing to the valve on Gas Pressures Sensor
3. Connect the Gas Pressure Sensor to LabQuest and choose New from the File menu.
4. On the Meter screen, tap Rate. Change the data-collection rate to 0.5 samples/second and the data-collection length to 180 seconds
5. Place the test tubes in a rack and label them 1,2,3, and 4.
6. Add 3 mL of 3.0% Hydrogen Peroxide and 3 mL of water to each test tube.
7. Use a clean disposable pipette to add 1 drop of enzyme suspension to test tube 1
8. Stopper the test tube and gently swirl to thoroughly mix the contents.
9. Connect plastic tubing to connector in rubber stopper
10. Monitor pressure readings
11. Disconnect plastic tubing connector when data collection has finished
12. Select any data point
13. Determine enzyme activity
14. store data
15. Find rate of enzyme activity
16. Label data
17. Clean test tubes
18. add water and Hydrogen Peroxide to each test tube
19. Clear Data
20. Display Graph
21. Measure enzyme activity at each temperature interval
In most parts of the graph, the reaction rate is increasing with time as the temperature is increasing.