Running head: LAB 5: INVESTIGATING AN ENZYME-CATALYZED REACTION
Lab 5: Investigating an Enzyme-Catalyzed Reaction
September 24, 2014
Principles of Biology 120.601
Mrs. Annemarie Duncan
This experiment was performed in order to examine ways in which a potato catalase enzyme reacts to various assays with differing variables. To do so a baseline assay (undiluted extract and room temperature H2O2) was used within the experiment with only one other variable changed in the other assays. These variables included a boiled, frozen and then thawed, and frozen potato extract and dH2O instead of the potato extract. It was noted that the temperature and or way the potato extract was prepared effects how the enzyme with the potato will react. Therefore the results of each assay varied, suggesting there is more than one way that a catalyzed reaction can occur.
The main purpose for this experiment was to explore how an enzyme catalase caused a reaction to catalyze through doing various assays using potato extracts. Enzymes are catalysts that are crucial in helping to speed up reactions, and catalase is a common enzyme found in almost every living organism that is exposed to oxygen. For this experiment, potatoes were used because they were previously known to have significant catalase activity. The potato catalase was mixed with hydrogen peroxide because the catalase helps to breakdown the hydrogen peroxide which helps determine how long a paper disk takes to float to the surface, which in return provides the time of the complete reaction. Since various assays were mostly used in combination with the potato extract, the extract should aid in speeding up the reactions with the assays that it is used. With the following information, the various ways that the assays were prepared within the realm of temperature differences, it was hypothesized that there would be a significant rate of reaction. If the reactions were to be similar, it would suggest a null hypothesis. Safety goggles were worn whenever handling the hydrogen peroxide.
Materials and Methods: (Allen)
Before this experiment begins, potato extract will be used as a source of catalase enzyme. In order to prepare the extract, 300 grams of potato are blended with 300 ml of ice and water. It than will be filtered through cheesecloth and the filtrate adjusted to a final volume of 600 ml. The extract should be kept on ice throughout this whole experiment. There will also be 3 other extracts experiments to do, one test tube full of the extract that will be thawed for 30 minutes before anyone is able to use it. The question is does different temperatures of the extract affect the outcome of the soaked paper disk. The materials needed for this experiment will be 0.3% of Hydrogen Peroxide, a 10ml of pipettes, pipetters, P1000 micropipette, blue tips, test tubes, racks, filter paper disks, graduated cylinder, flasks, beakers, forceps, timer, tape, markers. (Should be wearing goggles at all times during this experiment.) Also, the experiment will need some additional supplies, ice bucket, hot plate, water baths, and refrigerator. Experimental Procedure: (Allen)
In this experiment, before anything else clean all glassware that is being used in this experiment to get better results, than obtain about 100 mL of 0.3% H2O2 in a clean flask. After that obtain about 50 mL of potatoes extract and keep it on ice. Pipette 5 ml of 0.3% H2O2 into a clean test tube. Use tweezers to take a single piece of filter paper (do not touch with hands) and soak the paper disk in potato extract for 5 seconds or until it is completely covered in the solution.) Than place the disk into the test tube of H2O2 and wait for it to sink to the bottom and then start the timer. Once the disk rises to the top stop the timer and record the time. Do this 4 more times and record each result. Once that one is done do the Boiled...
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