The Effect Of Enzymes: Polyphenol Oxidase

Introduction Enzymes are catalysts that speed up chemical reactions without being used up in the process. Enzymes are able to do this by bringing two substrates together and having them bind to the enzyme itself. This allows the enzyme to lower the activation energy required to start the chemical reaction by forcing the substrates into an unstable transition state. In order to make sure the substrates fit, enzymes are able to mold their half-moon shape to fit around the substrates. Changing its shape allows the enzyme to force the substrates closer together in just the right way to allow the electrons to interact (Freeman, 2014). The first experiment was conducted using an enzyme called polyphenol oxidase that was extracted from a potato. This enzyme is crucial to the potato because it enables the potato to fight off bacteria and other parasites. The enzyme does so by speeding up the reaction that causes catechol to become an oxidized form of itself called benzoquinone. This reaction creates the browning appearance often seen when potatoes are bruised, or damaged. In addition, two control experiments were run. In each control experiment, one of the components in the first experiment was left out. The hypothesis of this experiment was that a brownish color change will happen in the …show more content…
The results showed that a brown color change occurred in the mixture. The reasoning behind the color change in the mixture has to do with the chemical reaction that changes catechol into its oxidized form benzoquinone. This chemical reaction also requires oxygen, and an enzyme called polyphenol oxidase. The enzyme polyphenol oxidase is needed because it acts as the catalyst in the reaction. When the components of buffer, substrate, and enzyme were mixed, the oxygen in the surrounding air also chemically reacted with the