Enzyme Lab Worksheet

Hypothesis:  If the pH of the solution used to interact with enzymes is lowered the reaction will occur more quickly.

Independent Variable:  The pH level of the solution mixed with the bindweed and hydrogen peroxide

Dependent Variable:  the reaction - the amount of bubbles and the speed at which they are produced when the bindweed enzymes are mixed with hydrogen peroxide

Controlled Variables:  Amount of peroxidase, amount of water, amount of enzymes, temperature of solution

Justification of hypothesis:  The lower pH solution will be more willing to react because of the level of reaction of solutions of high acidity.

Why did you choose this as your hypothesis?

It made the most sense to me; the seems more likely to react than base.

Materials (Your Team’s Experiment):  test tube, metric ruler, stopwatch, bindweed, hydrogen peroxide, sodium hydroxide, hydrogen peroxide, water, mortar and pestle, milliliter pipet, beakers.

Procedure:

1. Mash up one handful of bindweed with 30 ml of water in a mortar and pestle
2. filter using a paper towel into a separate glass, throw away paper towel
3. tape ruler, metric side, to test tube
4. extract 1 ml of bindweed solution into test tube
5. extract .7 ml of hydrogen peroxide into same test tube
6. observe bubbles and and time the rate of formation
7. record information
8. with a new test tube repeat steps 1-4
9. add .5 ml of hydrochloric acid to the bindweed solution
10. repeat step 5-7
11. with a new test tube repeat steps 1-4
12. add .5 ml of sodium hydroxide to bindweed solution
13. repeat steps 5-7
14. write out lab report
15. clean up lab space

Summary:  

The lab went well. While it would have been nice and more informative to have performed more tests, it simply was not realistic for the amount of time we had. One test for each does not yield a definite answer, but it is definitely enough to form a solid conclusion.

Detailed Steps:

Mash up one handful of bindweed with 30 ml of water in a mortar and pestle

filter using a paper towel into a separate glass, throw away paper towel

tape ruler, metric side, to test tube

extract 1 ml of bindweed solution into test tube

extract .7 ml of hydrogen peroxide into same test tube

observe bubbles and and time the rate of formation

record information

with a new test tube repeat steps 1-4

add .5 ml of hydrochloric acid to the bindweed solution

repeat step 5-7

with a new test tube repeat steps 1-4

add .5 ml of sodium hydroxide to bindweed solution

repeat steps 5-7

write out lab report

clean up lab space

Data and Results:

(This section should include at least one graph!)

Control

2.5 centimeters 0 seconds

3 centimeters 10 seconds

4 centimeters 13 seconds

5 centimeters 23 seconds

6 centimeters 37 seconds

rate:  .3 centimeters every second

pH level 12, sodium hydroxide

2.7 centimeters 0 seconds

3 centimeters 6 seconds

3.5 centimeters 15 seconds

rate: .5 centimeters every second

pH level 2-3, hydrochloric acid

2.7 centimeters 0 seconds

3.5 centimeters 14 seconds

4 centimeters 1 minutes 49 seconds

rate: .02 centimeters per second

Conclusions:  My hypothesis proved to be incorrect. The acidic solution had the slowest reaction rate, and produced fewer bubbles than the control. In the end, the enzymes reacted to the control the most, reaching six centimeters of bubbles in only 33 seconds. It had a reaction rate of .3 centimeters a second. Although this was slower than the .5 centimeters a second with the basic solution, it was much quicker than the .02 centimeters a second with the acidic solution. In addition, the control generated many more bubbles than either of the other solutions, two centimeters more than the base, and two and a half centimeters more the the acid. After these tests it is fair to conclude that plain water has a more powerful reaction with enzymes and hydrogen peroxide than acid or base.