Extracts from this essay...

Introduction

Investigation of the effect of temperature on the action of peroxidase enzyme to decompose hydrogen peroxide Aim To find the effect of temperature on an enzyme in this case peroxidase, by studying it decomposing hydrogen peroxide. Planning I am measuring the amount of gas given off in the reaction. By collecting this figure I can determine the rate of reaction. If I know the rate of reaction I can find out what temperature peroxidase works best at. Equipment Variables Change The temperature of the reactants: 60 50 40 30 20 10 Control Amount of peroxidase (10ml) Amount of hydrogen peroxide (20ml) Length of experiment (2min) Time between measurements (15sec) Equipment used Safety I will keep my safety goggles on at all times to prevent painful eye injury. Method For accuracy I am using six different temperatures and I will repeat the whole experiment twice.

Middle

Prediction My prediction is that peroxidase will work best at body temperature. In my preliminary experiments I discovered this reaction doesn't coincide with the collision theory. I found this because if you heat up the reactants the reaction is slower. Using the theory that enzymes are sensitive to temperature, cooling the enzymes slows down the reaction. When they warm up again they continue to work at their normal speed. Over heating permanently damages the enzymes because they change shape or become denatured. As the temperature rises, so does enzyme activity - until the enzyme becomes denatured then its activity falls suddenly to a zero. 15 30 45 60 75 90 105 120 60 20 40 43 70 75 80 85 90 50 50 70 80 110 130 130 135 135 40 80 110 120 130 180 190 200 200 30 20 25 30 35 70 75 80 85 20 20 22 25 29 30 33 37 41 10 25 30 40 45 48 50 58

Conclusion

they do not die. When you rise the temperature it makes the enzymes work harder and faster. This means my prediction was right. Evaluation Our results were a bit off but we didn't have any really bad ones, they fact that they weren't that good was because of the reactants being the wrong temperature. Or the gas not being read properly. Or the fact that there was already some air in the measuring cylinder. The experiment couldn't really have been improved but it could have been more efficient. Like we could have been more careful at reading the results and putting the water filled measuring cylinder in the trough. I think my results were correct because the look right on the graphs (there are no anomalous results) If I was to do this experiment again I would make the temperature band smaller in order to find the temperature at which the enzymes are denatured , something like between 34 and 43 degrees. This is because my graphs suggest that it be between those to temperatures at which the enzymes denature. Tom Stone 1