Potato Enzyme Lab Report

The instructor began our experiment by creating a catecholase enzyme solution using a chilled potato. He did this by removing the skin of the potato, this was necessary because the catecholase is contained under the skin. Another, reason is because if the skin is left on then the reading of the spectrophotometer would be inaccurate since the skin is brown as well as the benzoquinone. The potato was kept chilled so that the enzymes were not denatured. Next, the instructor chopped the potato and placed the pieces in a chilled blender along with 500 milliliters of chilled, distilled water. The water was used create a hypotonic environment so that the cells of the potato did not burst. He then blended the mixture with three, 10 second bursts so that the motor of the blender would not heat up causing the enzymes to denature. He did this to release the enzymes from the starch matrix of the potato. Once, the mixture was blended the instructor then used a cheesecloth and a funnel as a strainer to separate the starchy potato matric and other cell parts from the enzyme solution. Next, he filled it to the brim of the container and sealed

While the spectrophotometer was warming up we began to set-up our test tubes using the values seen in Table 1 as our guide. In test tube 1, we place 1 mL of enzyme and 2 mL of EDTU. In test tube 2, we placed 1 mL of enzyme and 2 mL of PTU. In test tube 3, we placed 1 mL of enzyme and 2 mL of citric acid. Finally, in test tube 4, we placed 1 mL of enzyme and 2 mL of dH2O. Once, these components were added to the test tubes they were left at room temperature for 10 minutes stirring the mixtures every 2 minutes. It is to allow the chelating agent to fully mix with the enzyme and allow the chelating agent to bind to their respective metallic ion. The catechol is added after the 10 minutes so that the reaction does not start