For Activity A, we first tested enzyme activity. First, we used an H2O2 syringe to transfer 10 mL of H2O2 into an unlabeled 60-mL cup. Then, we used a transfer pipet to add one mL of catalase solution into the unlabeled 60-mL cup that we put H2O2 in. After that, we observed the solution for one minute. Then we tested the effect of boiling on enzyme activity. First we used a transfer pipet to transfer 4 mL of catalase into a test tube. After that, we placed the test tube filled with catalase in a boiling water bath for five minutes. While we were waiting, we rinsed the unlabeled cup we used earlier when we tested enzyme activity.
Then we used a H2O2 syringe to transfer 10 mL of H2O2 into the rinsed unlabeled cup. After five minutes, we transferred 1 mL of the boiling catalase into the unlabeled cup with H2O2 in it with an unused transfer pipet and observed the results. After testing the effect of boiling on enzyme activity, we tested for catalase in living tissue. First, we rinsed the unlabeled 60 mL cup we used earlier. Then, we used a scalpel to cut a small piece of liver. After that, we macerated the piece of liver with a glass rod. When the liver was macerated enough, we put it in a cup with 10 mL of H2O2, which was transferred into the cup with a H2O2 syringe.
Lastly, we observed the cup. Procedures for Part B: First, we used a clean syringe labeled H2O2 and filled it with H202. Then, we transferred the contents of the syringe into a 60 mL cup labeled Baseline. Second, we used the plastic transfer pipet to add 1 mL of distilled water and added it to the Baseline cup. Third, we used the syringe labeled H2O2 to add 10 mL of H2O2 and transfer that into the Baseline cup. Fourth, we gently swirled the contents of the Baseline cup to mix the solution. Then, we used the syringe labeled Transfer and removed 5 mL of the solution in the Baseline cup into the cup labeled Titration.
Lastly, we titrated the 5 mL sample of the Baseline solution. To titrate the solution, we filled the titration syringe with 10 mL of KMnO4. Then, we added one drop of KMnO4 into the titration cup while gently swirling the contents of the cup until the purple color disappears. We repeated adding one drop of KMnO4 until the solution in the titration cup changed into a light brown color. Procedures for Part C: First, we lined up the 60 mL plastic cups labeled 10 sec, 30 sec, 60 sec, 120 sec, and 180 sec. Second, using a syringe, we transferred 10 mL of H2O2 into each cup.
Third, we added 1 mL of catalase into the 10 sec cup, using a transfer pipet and gently swirled the contents of the cup. After 10 sec, we added 10 mL of H2O2 while gently swirling the contents of the cup. Then, we repeated the last 3 steps for each cup, but allowed the reactions to proceed for 30, 60, 120, and 180 second as assigned before adding the 10 mL of H2O2. After adding the H2O2 to all of the cups, we removed 5 mL of each solution of each cup and transferred it into a separate cup labeled titrate. Lastly, we titrated each cup filled with sample solution until each solution reaches endpoint.