Peroxidase Lab Report
Determining the Catalytic Properties of the Enzyme Peroxidase
Extracted from a Turnip
Under the Conditions of Temperature, pH, Boiling and Competitive Inhibitors
By
Robin Caserta
BIO 101
September 30, 2013
ABSTRACT
The enzyme, peroxidase, extracted from a turnip was tested for its efficiency in binding to its substrate and its stability under several conditions. To do this, we tested effects on peroxidase activity, first, with different amounts of the enzyme, next at temperatures of 4oC, Room Temperature, 32oC, 48oC and boiling; then, at pH 3, pH 5, pH 7 and pH 9; and, finally, with the competitive inhibitor, hydroxylamine. We were able to measure enzymatic activity by the change in absorbance per second with a spectrophotometer. By testing different concentrations of peroxidase and its reaction rate in seconds, we were able to see that as the amount of enzyme increased the catalytic reaction also increased. The optimal amount of peroxidase concentration to be used in the subsequent experiments was determined to be 1.0 mL. Any amount above this would have caused the rate of absorbance to be too fast, making it too difficult to get accurate readings. Any amount below this would not have produced a reaction “at an appreciable rate.” (Dolphin, Vleck, Colbert and Westgate, p. 76) In addition, our results show that a rise temperature and pH only increase the rate of reaction to a certain point before the reaction rate begins to decline dramatically. In the case of boiling of the enzyme there was no rate of reaction found whatsoever. A similar result was found when hydroxylamine was added to the peroxidase and it caused an inhibition reaction. Overall, the results show that the peroxidase enzyme is sensitive with reference to the above factors in whether or not a reaction is catalyzed.
INTRODUCTION Enzymes are essential in the breakdown of certain materials or molecules that cannot be used by or are harmful to an organism as they are,
Extracted from a Turnip
Under the Conditions of Temperature, pH, Boiling and Competitive Inhibitors
By
Robin Caserta
BIO 101
September 30, 2013
ABSTRACT
The enzyme, peroxidase, extracted from a turnip was tested for its efficiency in binding to its substrate and its stability under several conditions. To do this, we tested effects on peroxidase activity, first, with different amounts of the enzyme, next at temperatures of 4oC, Room Temperature, 32oC, 48oC and boiling; then, at pH 3, pH 5, pH 7 and pH 9; and, finally, with the competitive inhibitor, hydroxylamine. We were able to measure enzymatic activity by the change in absorbance per second with a spectrophotometer. By testing different concentrations of peroxidase and its reaction rate in seconds, we were able to see that as the amount of enzyme increased the catalytic reaction also increased. The optimal amount of peroxidase concentration to be used in the subsequent experiments was determined to be 1.0 mL. Any amount above this would have caused the rate of absorbance to be too fast, making it too difficult to get accurate readings. Any amount below this would not have produced a reaction “at an appreciable rate.” (Dolphin, Vleck, Colbert and Westgate, p. 76) In addition, our results show that a rise temperature and pH only increase the rate of reaction to a certain point before the reaction rate begins to decline dramatically. In the case of boiling of the enzyme there was no rate of reaction found whatsoever. A similar result was found when hydroxylamine was added to the peroxidase and it caused an inhibition reaction. Overall, the results show that the peroxidase enzyme is sensitive with reference to the above factors in whether or not a reaction is catalyzed.
INTRODUCTION Enzymes are essential in the breakdown of certain materials or molecules that cannot be used by or are harmful to an organism as they are,
Citations: Dolphin, W. D. with D. Vleck, J. Colbert and L. M. Westgate (2011). Biological Investigations: Form, Function, Diversity & Process. Ninth Ed. New York: McGraw-Hill.