Enzymes are proteins that velocity up reactions in cells. Each of these enzymes speed up the reaction by adhering to a substrate at the enzyme ‘s active site doing this substrate to divide into the reaction ‘s merchandises. These enzymes work by cut downing the activation energy of a reaction so that the reaction is easier to start.1 Each single enzyme catalyzes 1000s of reactions per minute and is important to the procedures of a cell. One of these enzymes is catalase which breaks down H peroxide ( H2O2 ) into H2O and O. It does this by undergoing a decomposition reaction to organize these products.2 In this experiment, a solution of H peroxide will undergo a reaction with catalase to see the rate that H peroxide is consumed over a set interval. The reaction must be stopped at a certain interval, so sulphuric acid must be added to alter the pH so that the catalase denatures. To mensurate how much H peroxide is used, a compound called K permanganate ( KMnO4 ) is added to respond with the extra H peroxide. This procedure works because the H peroxide and K permanganate are reactants in the reaction, so when all of the H peroxide is used up, the K permanganate turns the solution to a brown color.3 The intent of this experiment is to happen the reaction rates of catalase and H peroxide over a certain clip period as compared to the normal decomposition of H peroxide. It is hypothesized that the catalase catalyzed reaction will follow a logarithmic curve as less H peroxide is readily available over clip. It is besides hypothesized that more H peroxide will be decomposed in 60 seconds in the presence of catalase than in the 3 yearss of natural uncatalyzed decomposition of H peroxide.
Materials and Methods
Catalase Extract
1M H2SO4
2 % KMNO4 solution
Distilled H2O
1.5 % H2O2
9: 60 milliliter beakers
2: 5 milliliter panpipes
2: 10 milliliter panpipes
Stopwatch
Experiment 1:
10 milliliter of 1.5 % H2O2 is placed into a beaker. Add 1 milliliter of H2O to the beaker so 10 milliliters of 1M H2SO4 to the beaker and mix good. Remove a 5 milliliter sample from the beaker to utilize for the titration. To titrate, take 5 milliliter of the 2 % KMNO4 solution and add one bead at a clip, twirling each clip before adding another bead. Continue this until there is a permanent colour alteration in the beaker. Record the sum of 2 % KMNO4 solution used.
Experiment 2:
Add 15 milliliter of H2O2 to a beaker and go forth it exposed for 24 hours. After the 24 hours is up, reiterate the titration procedure from experiment 1 and enter the consequences.
Experiment 3:
Add 10 milliliter of H2O2 to 7 beakers. Add 1 milliliter of catalase to each beaker and step out times of 10 seconds, 30 seconds, 60 seconds, 120 seconds, 180 seconds, and 360 seconds. At each interval, add 10 milliliter of 1M H2SO4 to the beaker and mix good. After each reaction has been stopped, reiterate the titration procedure from experiment 1 on each beaker and record the results.3
Consequences
Table 1- Initial and Final Readings of H2O2: Base line
Base Line Readings
Initial Reading
5 milliliter
Final Reading
8.5 milliliter
Table 2- Initial and Final Readings of H2O2 Naturally Decomposed
Natural Decomposition Readings
Initial Reading
5 milliliter
Final Reading
8.5 milliliter
Table 3- Initial and Final Readings of H2O2 Decomposed in a Catalyzed Chemical reaction
10 unsweet Readings
30 unsweet Readings
60 unsweet Readings
90 unsweet Readings
120 unsweet Readings
180 unsweet Readings
360 unsweet Readings
Initial Reading
5.0 milliliter
5.0 milliliter
5.0 milliliter
5.0 milliliter
5.0 milliliter
5.0 milliliter
5.0 milliliter
Final Reading
8.2 milliliter
8.0 milliliter
7.4 milliliter
7.4 milliliter
7.0 milliliter
6.8 milliliter
6.6 milliliter
Discussion
In this experiment, it was hypothesized that the decomposition of H peroxide in a catalase- catalyzed reaction will follow a logarithmic curve, and that more H peroxide will be consumed in the catalyzed reaction in 60 seconds than the natural decomposition over 3 yearss.
Table 4: Sum of H2O2 Consumed
10 unsweet Readings
30 unsweet Readings
60 unsweet Readings
90 unsweet Readings
120 unsweet Readings
180 unsweet Readings
360 unsweet Readings
Base Line Amount
3.5 milliliter
3.5 milliliter
3.5 milliliter
3.5 milliliter
3.5 milliliter
3.5 milliliter
3.5 milliliter
Initial Reading
5.0 milliliter
5.0 milliliter
5.0 milliliter
5.0 milliliter
5.0 milliliter
5.0 milliliter
5.0 milliliter
Final Reading
8.2 milliliter
8.0 milliliter
7.4 milliliter
7.4 milliliter
7.0 milliliter
6.8 milliliter
6.6 milliliter
Sum of KMnO4 Consumed
3.2 milliliter
3.0 milliliter
2.4 milliliter
2.4 milliliter
2.0 milliliter
1.8 milliliter
1.6 milliliter
Sum of H202 Used
0.3 milliliter
0.5 milliliter
1.1 milliliter
1.1 milliliter
1.5 milliliter
1.7 milliliter
1.9 milliliter
After analyzing Table 4 and Table 2, the hypothesis is proven right by two factors. The first factor is that the rate of the catalase catalyzed reaction is tapering off over clip. An illustration of this is that it takes 60 seconds to break up 0.2 milliliter of H peroxide ( 120 sec to 180 sec ) , but the it takes 180 seconds to break up the same sum. All of this decelerating down is illustrated in Figure 1. This lag is due to the fact that the more hydrogen peroxide is decomposed, so the less hydrogen peroxide is readily available. At a molecular degree, this comes down to the enzymes holding problem happening H peroxide in the solution therefore less of it is decomposed. The 2nd factor that proves the hypothesis true is the fact that there was no alteration in the sum of H peroxide in the beaker after being left out for 3 yearss. This is due to the fact that the decomposition of H peroxide is an highly slow procedure that can take months before and noticeable alteration is found in the sum of H peroxide available. This slow decomposition is the ground that enzymes are an indispensable portion of all cellular procedures because big sums of H peroxide can be lethal to a cell. With these factors in head, the hypothesis is proved correct in all facets and this experiment shows the necessity of indispensable enzymes that help all cells maintain a balanced equilibrium.
Figure 1: Sum of Hydrogen Peroxide Used Over Time
Citations
Campbell, Neil A. , and Jane B. Reece. Biology. 7th erectile dysfunction. San Francisco: Pearson, 2005. 151. Print.
George, P. “ Reaction Between Catalase and Hydrogen Peroxide. ” Nature 12 July 1947: n. pag. Web. 11 Nov 2010. & lt ; hypertext transfer protocol: //www.nature.com/nature/journal/v160/n4054/abs/160041a0.html & gt ; .
Biology Lab Manual for Students. The College Board, 2001. 19-22. Print.
