Enzyme Lab Final Report

Enzyme Lab Final Report

Does the pH of solutions mixed with enzymes affect the reaction rate of the enzymes.

Introduction:

In our experiment, we tested the speed of reactions of bindweed enzymes when mixed with hydrogen peroxide. To conduct our experiment, we extracted hydrogen peroxidase enzymes from ground up bindweed leaves and mixed them with water, acid, or base. Then we added hydrogen peroxide to the mix, which was split from H2O2 into H2O and O2 by the catalase. The carbon dioxide in this reaction produced enough bubbles to be measured in height and speed to let us judge the rate of reaction.

Purpose:

The purpose of this lab is to find out how much a specific enzyme can react when being mixed with solutions of different pHs. Therefore, we will see if the bindweed plant can benefit from being watered with different pH levels since that would help the enzymes within them work faster.

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.

Materials (Your Team’s Experiment):  

test tube, metric ruler, stopwatch, bindweed, hydrogen peroxide, sodium hydroxide, hydrogen peroxide, water, mortar and pestle, milliliter pipet, beakers.

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

Data Analysis: The graph clearly indicates that the control, the solution with a pH of 7, had the fastest reaction with the enzyme. Obviously and acid or a base is not going to be as effective.

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.