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The aim of this investigation is to find out the effect of pH on an enzyme activity (Catalase).

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Introduction

The aim of this investigation is to find out the effect of pH on an enzyme activity (Catalase). This reaction is about the enzyme catalase and how it is affected by pH. Enzymes are affected by a number of different factors, these are:- * pH * temperature * surface area * concentration In this investigation I will be looking at the effect of pH. Different digestive reactions happen in the different parts of your alimentary canal. The different parts have different levels of acidity or alkalinity (different pHs). Very acid Neutral Very alkaline pH 1 7 14 Increasing acidity Increasing alkalinity The level of acidity or alkalinity is measured on the pH scale. Each digestive reaction is controlled by a different specific enzyme which works best at the pH which exists in the region of the alimentary canal, where it controls digestive reactions. A catalase is an enzyme; an enzyme is a biological catalyst. Catalysts speed up the rate of reactions without being used up. In this investigation catalyse will catalyse the Hydrogen Peroxide. Hydrogen Peroxide Water + Oxygen H2O2 H2O O2 In the human body a catalase is produced in the liver. ...read more.

Middle

the syringe * Place measuring cylinder into water bath once thoroughly rinsed and make sure it is aerated, then stand up the cylinder. * Place the long tube coming conical flask into the cylinder. * Once syringed the H2O2 into the flask start stop watch. * Once 25ml of oxygen has been collected stop the stop watch. I will repeat each experiment three times; I will find the average results for accurate measurements. For this investigation to be accurate and for me to reach a firm conclusion I will need to insure that my experiment is a fair one. For this to happen I will need to make sure of and carry out the following: * The temperature will need to be constant - this was done at room temperature, by using a thermometer. * Use the same potato for each experiment. * Make sure the potato is grated to a similar size. * Use separate pipettes for each solution. Make sure it's not cross contaminated. * The Peroxide solution should come from the same bottle for each experiment. I will need to follow a set of rules for safety measures. These are: * To wear goggles at all times. ...read more.

Conclusion

I found out that the catalase works best at a pH of 7.5. This is the optimum pH. If the pH is above or below the optimum pH, it will begin to denature. As you can see from my results table and my graphs, catalysts work best at a particular pH. Graph A shows that at a pH of 4.4 it takes a long time to collect 20ml of oxygen. This is because there is very little enzyme activity, as you can see on Graph B. At a pH of 5.2 and also 6.5 the time taken to collect 20ml of oxygen is very short. This you can see on Graph A. Graph B shows that there is still, very little enzyme activity. However, Graph A shows that the time taken to collect 20 ml of oxygen is a lot less than any other pH. This is for pH 7.5. Graph B shows that pH 7.5 has the most enzyme activity. This is can prevent the Graph B shows that at a pH of 8.4, the enzyme activity has dropped, Graph A shows that it is taking a long time to collect 20ml of oxygen. As you can see from both Graph A and B, 7.5 is the optimum pH. My predictions are correct. The effect of pH on the activity of catalase Fariha Choudhury 13228 9100 ...read more.

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