Catechol Oxidase Experiment

                                                Introduction

            From the laboratory information collected, it implies that a large percentage of enzymes always possess a defined 3-D structure. Any change which occurs within their structure is the one which causes a considerable change in their activity. Lab research suggests that it is the pH of the entire reaction which has the capacity of modifying the structure of the enzymes hence altering its activity (Wood, 2014).

                                                Materials

            5 test tubes

            Control test tube

            pH scale

            Catechol oxidase extracts

            Lead solution

           

                                                Procedure

Prepare each reactant with pH values ranging from 2, 4, 6, 7, and 8 respectively.

Then label each of the five test tubes with their pH values

Add ¼ capacity to the test tubes

To each test tube, add 10 drops of the catechol oxidase extracts

Add 10 drops of catechol to each test tube

Carefully, shake each test tube to ensure that the contents have mixed as required

Note the color change of each test tube and record their respective color range using the pH scale.

Continue shaking each test tube and note color change after every 5 minutes for a duration of 20 minutes.

                                                            Results

                        A graph showing the enzyme activity in each tube against time

            Y-Axis

                     9

                     8

                     7

                     6             A         B         C                         D

                      5

                      4

                     3

                     2

                       1

X-Axis

                                                    5                10                   15                   20

 

                                                                                    Time (seconds)

                                                KEY

                                                A –Test tube A

                                                B- Test tube B

                                                C-Test tube C

                                                D-Test tube D

               Based on the information collected above, we reject the null hypothesis because it does not take into consideration the impacts the pH has on the enzyme’s activity. The pH of such an enzyme is the one which have the capacity of affecting its enzymatic activities. Moreover, we fail to reject the alternative hypothesis because the graph indicates that the pH of the enzyme will have the capacity of affecting its activity. During the experiment, it was noted that the smaller pipette was not efficient in adding the reactants but it did not affect the measurements

              During the experiment, the enzyme was mixed with varying buffer solutions which in return inhibits its activity. At the same time, the buffering solutions are used for the purpose of trying to pH changes in the test tubes. In order to determine how active the enzyme is, it is important to measure the intensity of the color formed when the mixtures are given time to react fully. Using the control tube, it becomes easier to determine the volume of lead which was used to inhibit the enzyme.

                                                             Conclusion

The data collected indicates that the pH and the concentration of the catechol oxidase enzyme is the one which affects or increases the intensity of the brown color in the reactants. It should be noted that enzymes have an optimum pH within which they show maximum activity (Sigel et al., 2009). Any slight difference in the pH of an enzyme is the one which also reduces its activity. Basically, Catecheol oxidase has an optimum pH of about 7. The turning of fruits and vegetables browns is due to the effect of Catechol oxidase enzyme. The release of Catechol oxidase is when plant cells have been damaged. It is these damaged cells which react with this enzyme to form benzoquinone.

 

 

 

 

 

 

 

 

                                                            References

Sigel, A., Sigel, H., & Sigel, R. K. O. (2009). Metal-carbon bonds in enzymes and cofactors. Cambridge, UK: RSC Publishing.

Wood, E. J. (2014). Practical Biochemistry for Colleges. St. Louis: Elsevier Science.