Enzyme Lab Activity

By Amir Ziaei


What effect do enzyme concentration and temperature have on enzyme activity?

Identification of Variables

The independent variable is time, which is measured in seconds.

The dependent variables are enzyme concentration and temperature.

The constant is what the enzymes are composed of.


If the enzyme concentration increases, then the rate of reaction increases before it plateaus.

If the temperature increases, then the rate of reaction will increase at first, then decrease.


-LabQuest and app

-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

-enzyme suspension

-four 18x150 mm test tubes


-pH buffers (4, 7, 10)

-test tube rack


-four dispensable pipettes

-Logger Pro



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

Big image
Big image


Temperature makes the enzyme activity increase.

In most parts of the graph, the reaction rate is increasing with time as the temperature is increasing.