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To investigate the effect of changing concentration of hydrogen peroxide (H2O2) on the enzyme catalase

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To investigate the effect of changing concentration of hydrogen peroxide (H2O2) on the enzyme catalase 2 H2O2 + catalase 2H2O + O2 Background information H2O2 is a by-product of a chemical reaction inside the body metabolism. H2O2 has to be broken down into less toxic compounds or molecules. All enzymes are proteins. Temperature affects the rate an enzyme works, all enzymes work best at body temperature. Excess heat denatures enzymes rendering them useless. Catalase is an enzyme designed especially for H2O2. It works under a lock and key theory, where the catalase is the key and the H2O2 is the lock e.g. Rate Rate Substrate concentration enzyme concentration Reaches a plateau because all the Plenty of enzyme molecules to enzyme molecules are used up so deal with the substrate. ...read more.


Amount of catalase If more the enzyme would work faster. Here is an annotated diagram to explain the way I am going to carry out the experiment. I will carry out this experiment with 1,2,3,4,5&6? concentration of H2O2 repeated 6 times. To make my results make my results accurate I will take all the precautions I have pointed out in the planning and make sure I use the same equipment (washed out) every time. I will find out the rate by dividing the mean by the time (3 minutes). Hypothesis I predict that the rate of reaction will decline as I add substrate. I think this will happen because if you add more substrate to be broken down with the same amount of catalase, the catalase will have too work harder, slowing the rate. ...read more.


Evaluation The limitations in my method were, using 0.5g of yeast (the catalase) if I had've used more catalse, the rate of the reaction would steadily get faster as there is plenty of enzyme to deal with the substrate. Also, only doing the experiment with 1,2,3,4,5& 6 % of substrate, if we used more the reaction reach a plateau because the there would be too much H2O2 for the enzyme to deal with. There are many reasons why I could get anomalous results for example, human error (reaction times, equipment set up wrong). Luckily I did not get any anomalous results. To extend my investigation I would take the results and try to find any connections e.g. the rate against the mean may be proportional in some way? Overall the expt went really well and I got fairly accurate results, with witch I investigated the reaction. ...read more.

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