Catecholase Lab Report

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Michele Harman BI 112 Cell Biology March 3, 2009 Lab Report Final Draft The Rate of Reaction of Catecholase and Various pH Levels Purpose of Experiment To determine how the pH levels 3, 7, 9 affect the rate of reaction of the enzyme catecholase and its substrate catechol. Introduction The cells of living organisms are constantly performing thousands of chemical reactions to complete necessary functions and processes. These chemical reactions are required to happen extremely fast and precisely in order for cells to function properly. For cells to do this, they need to lower the activation energy. Activation energy is the amount of energy needed to start a chemical reaction. One way to lower activation energy is heat, but…show more content…
The rate of reaction is determined on a level of 0 to 4 which is slowest to fastest. Throughout the chemical reaction (the production on benzoquinone), there will be a series of color changes. At the very beginning the enzyme and substrate will be clear; as the benzoquinone is produced there will be a gradual change to a faint peach-ish color, then yellow to orange-ish red, and then on to its final stage at a dark brick reddish color (benzoquinone has now been produced). The time it takes for the enzyme to change to dark red is the rate of reaction. (2.) The enzyme with its substrate was exposed to three different pH levels. The pH levels that the enzyme with its substrate was exposed to are 3, 7, and 9. The rate of reaction with the exposure of each pH level was then measured. The dependant variable of this experiment will be the rate of reaction of the enzyme catecholase with its substrate catechol. The independent variable of this experiment is the various pH levels that the catecholase and catechol are exposed…show more content…
We thought that a pH level of 3 would be the optimal pH level for the enzyme catecholase and its substrate catechol to react in. There was no prior knowledge on the effect of pH levels on catecholase and catechol. The results of the experiment did not confirm this hypothesis; instead the hypothesis was rejected by the results of the experiment. The results showed that tube 1 had the slowest rate of reaction, and actually did not react at all. The results showed that tube 2 had the fastest rate of reaction; this tube was exposed to the neutral pH of 7. The results showed that tube 3 had the second to fastest reaction time; this tube was exposed to the more basic pH of 9. Tube 4 was the control tube and reacted the third fastest. The conclusion of the experiment is that the enzyme catecholase and its substrate catechol react the most efficiently in their most optimum pH level of 7, which is neutral. The catecholase enzyme and its substrate catechol cannot react in a pH level of 3, which is too acidic. The acidity of this pH level denatured the enzyme, thus destroying its ability to catalyze the reaction and stopping the production of benzoquinone.
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