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Introduction

The effect of pH on the activity of catalase Introduction Enzymes are biological catalysts. Catalase, an enzyme found in many tissues, catalyses the breakdown of hydrogen peroxide (H2O2) into water and oxygen. It is one of the fattest known enzymes. 2H2O2 catalase O2 + 2H20 Enzymes speed up reaction but not involved in the reaction. They provide a surface for reaction to occur. They also work very rapidly in reactions. Observation Enzymes are globular proteins that increase the rate of specific biochemical reactions; they act as organic and biological catalyst. Enzymes are specific for the reaction they catalyst. Each enzyme operates on a limited number of substrates of similar to generate product under well-defined conditions of concentration, pH, temperature etc. Hypotheses I predict that catalase will work at its optimum at pH 7 to 8. The optimum pH for most enzymes is neutral that is pH 7.Catalase will be denatured at in acidic conditions as the globular three dimension shape will be tortured and permanently be destroyed. Requirements This experiment will be successful done with these materials: Buffer solutions at pH 4.4, pH 5.2, 6.5 and pH 7.5.you will also need a pod, a burette, a pipette, Hydrogen peroxide, syringe, stop clock, test tubes, stoppers, Safety measures Hydrogen peroxide is an irritant product; it bleaches the skin instantly as it gets to it, therefore extra care must be taken when using it. ...read more.

Middle

7.7 5.4 12 9.27 90 9.1 11.8 15.3 7.9 9 6.3 13.2 10.37 105 9.9 12.3 16.1 9.1 10.2 7.2 14.3 11.30 120 10.7 12.8 16.6 10.1 11.2 8 14.8 12.03 135 11.5 13.2 17 11.1 12.1 8.5 15.7 12.73 150 12 13.5 17 11.7 12.7 9.1 16.2 13.17 165 12.4 13.8 17.7 12.4 13.4 9.6 16.6 13.70 180 12.8 14.1 17.9 13 13.9 9.8 17.1 14.09 ph7.5 Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7 Mean Time (s) Volume Volume Volume Volume Volume Volume Volume Volume 0 0 0 0 0 0 0 0 0.00 15 3.1 7.2 3.9 1.3 2.9 2.4 5 3.69 30 7.7 11.5 9.9 3.1 8.2 4.4 9 7.69 45 10 13.4 12.9 5.9 11.4 7 11.9 10.36 60 11.7 14.4 14.9 8.1 13.3 9.2 13.5 12.16 75 12.9 15 16.2 9.9 14.7 11 14.6 13.47 90 13.7 15.5 17.1 11.3 15.7 12.3 15.5 14.44 105 14.4 15.9 17.5 12.4 16.4 13.4 16.2 15.17 120 15 16.1 18 13.3 16.9 14 16.8 15.73 135 15.5 16.5 18.6 14 17.4 14.6 17.2 16.26 150 15.8 16.7 18.8 14.7 17.7 15.1 17.7 16.64 165 16.2 16.8 19 15.2 18 15.8 18 17.00 180 16.5 16.9 19.2 15.7 18.3 16 18.3 17.27 Mean of all the results PH4.4 ph5.2 ph6.5 ph7.5 0 0.00 0.00 0.00 0.00 15 1.29 0.84 1.50 3.69 30 4.23 2.89 3.87 7.69 45 6.27 5.00 6.13 10.36 60 ...read more.

Conclusion

It may also be that the enzyme catalase haven't yet reached its optimum or had passed it optimum slightly, this would have be confirm or dealt with if say pH 7 and pH 8 was used in this experiment. With reference to my error bars on mine graph, it is shown clearly how accurate the class mean was on each pH. It is also shown clearly that if I compare pH's 4.4 and 6.5 to pH's 5.2 and 7.5, I can tell that because the error bars on pH 4.4 and 6.5 are spreadout , the results are less accurate then that of pH's 5.2 and 7.5 which are much much closer. Evaluation Overall I think my hypothesis was correct and the experiment proved it. There are so many factors that could contribute to some improvement in the method. One isa gas syringe could have been used to measure the volume from the burette was turned upside down and many people found it difficult reading the the volume taken at each time interval. Time could also cause a be error as time may be different at diferrent times and redings may be inaccurate. Another cause of an error in this pratical could be reading the volume on the burette, this was because the readings were white and was almost the same colour as the water and therefore made it difficult to read and record accurate volumes. This could be eliminated next time by using burettes with coloured readings when repeating this practical. ...read more.

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