The results of the experiments show that our hypothesis a) that ‘increasing the concentration of the substrate will increase the level of activities of the enzyme’ has only been partially confirmed as an increase in concentration of the substrate will lead to an increase in enzyme activity only up to a point where the maximum rate for that reaction is reached. Beyond this point, any increase in concentration of the substrate will have no effect on enzyme activity as too many substrate molecules are competing for the active sites. The hypothesis b) that ‘increasing the concentration of the enzyme will increase the level of activities of the enzyme catalase’ has been confirmed by the results of the experiment which shows that the amount of increase in enzyme activity is proportional to the increase in concentration of the enzyme except for exceptionally high concentrations of the enzyme. Results of the experiment also confirm our hypothesis c) that ‘the enzyme’s activities maximised at an optimum of pH 7 and that the enzyme’s optimum pH range was 5 to 9. The enzyme experienced a decrease in activity when it was exposed to extremes of pH (i.e. below 4 and above l0)’ which were outside its optimum pH range. Finally, the results of the experiment indicate that our hypothesis d) has only been partially confirmed as an increase in temperature only brings about an increase in enzyme activity up to the optimum temperature of 25°C. After this temperature, any increase in temperature does not result in an increase in enzyme activity as the peptide bonds have been affected by the increase in temperature and the enzyme functions less efficiently as a catalyst. After 50°C, no enzyme activities were recorded as the enzyme had been denatured. We have also learned that the enzyme, catalase is specific and that is, it only acts on hydrogen peroxide, and not any other resolutions used in the experiment. We were able to verify this fact as the above tests showed no activities when a paper disc soaked with the enzyme catalase was placed into the solution with no hydrogen peroxide present.

From the above experiments, we have learned that the activities of the enzyme catalase can be seriously affected by environmental factors such as differences in pH, temperature and concentration of the substrate and enzyme. Knowing about this helps us to better understand how the enzyme in our own system works as neither the extracellular nor intracellular cell environment is uniform. For instance, the pH in our stomach is 2 while the duodenum has a pH of 8.5. On top of that, there are also the problems of salt concentration, substrate, enzyme concentration and inhibitors which seriously affect enzyme activities. Knowing that the enzyme would be destroyed at a temperature of 50º C, we would try to maximise our intake of the enzyme by consuming more uncooked food items such as fruits and vegetables. Our life relies to a certain extent on catalases to protect our cells from DNA damages, so it is worth the time to know more about how the enzyme works.

Possible errors may have occurred in measuring the exact quantity of the solutions each time. This error can be avoided by repeating the experiments a few more times. Another error may have occurred in not rinsing the test tubes thorough enough so that traces of the substrate or enzyme may have affected the results. This may be avoided by rinsing the test tubes a few more times. We have repeated the above experiments for many times and are satisfied that the evidence collected is sufficient to support the conclusions that we have arrived.