The oxygen can b e observed as bubbles coming from the reaction site. Catalane is found in m any living tissues of organisms, including chicken liver. The purpose of this experiment is to determine what changes in pH, temperature, and enzyme e concentration have on the rate catalane works to break down hydrogen peroxide. If the pH, temperature, or enzyme concentration changes, then the reaction rate of catalane will either speed up or slow down.
Materials and Procedures Materials needed include 1 molar HCI solution, 1 molar Noah solution, 6 test tub SE, measuring pipette, ml graduated cylinder, 40 ml 3% hydrogen peroxide solution , straightedge razor blade, scissors, forceps, stirring rod, fresh liver, fresh apple, fresh potato, test tube holders, ice bath, warm water tat, and boiling water bath. Place 2 ml of the 3% hydrogen peroxide solution into a clean test tube. Using force peps and scissors, cut a small piece of liver and add it to the test tube. Push it into the hydrogen p reside with a stirring rod.
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Observe the bubbles. Assume this reaction is rated 4 on a scale of 05. This reaction is the control group for the experiment. The 05 s call based on bubbles is the measurement technique for each experiment. Pour off the liquid into a second test tube. This used liquid is the independent variable . Add more liver to this liquid. Record the reaction rate. The reaction rate will be the depend NT variable in each experiment. Add another 2 ml of hydrogen peroxide e to the liver remaining in the first test tube. Record the reaction rate.
Place 2 ml of hydrogen peroxide in each of 3 clean test tubes and then add each of the three test substances (potato, apple, chicken) to the tubes. The t here substances are the independent variables. As you add each test substance, record the reaction rate for each tube. C Put a piece of liver into the bottom of a clean test tube and cover it with a small a mount of water. Place this test tube in a boiling water bath for 5 minutes. Remove the test tube from the hot water bath, allow it to air cool, then pour out the water.
The fact that the liver was boiled is the independent variable. Add 2 ml of hydrogen peer oxide. Use a tested holder for hot test tubes. Record the reaction rate. Put equal quantities of liver into 2 clean test tubes and 1 ml H2O into 2 other test tubes. Put one test tube of liver and one of H2O into an ice bath. Place the other set in a warm water bath (not boiling). The temperature of each set of liver and peroxide e is the independent variables. After 3 minutes, pour each tube of H2O into the responding tube of liver and observe the reaction. Record the reaction rate.
Add 2 ml hydrogen peroxide to each of 5 clean test tubes. Add 4 drops of HCI to t he first test tube, 1 drop HCI and 3 ml water to second, 4 drops Noah to third, 1 drop Noah and 3 ml water to fourth, and 3 drops water to fifth. The independent variable is pH of the solution added to each test tube. Add liver to each of the test tubes at the same time. Record the reaction rate of each tube. Results,Data Collection, and Analysis The H2O fully reacted with the catalane in the first experiment because it did no t react anymore hen more catalane (liver) was added.
However, the catalane was still pre sent after the reaction because it converted additional H2O at the same reaction rate. The reaction rates of the three tests are in the following table: Substance Rate of Reaction (05) normal hydrogen peroxide and liver 4 reused hydrogen peroxide reused liver The potato, apple, and chicken liver all contained catalane became use they caused a noticeable reaction when hydrogen peroxide e was added. The reaction rates of the three test substances: Potato 5 Apple 3 Chicken liver Boiling the liver caused no reaction when added to hydrogen proper De.
The cold liver and peroxide reacted much faster than the war m liver and peroxide. The reaction rates of the three substances: boiled liver and hydrogen peroxide cold liver and hydrogen peroxide warm liver and hydrogen peroxide The reactions in acids were slower than the neutral and weak base reactions, which were slower than the strong base. The e reaction rates of the acidic, neutral, and basic substances: HCI solution 2 diluted HCI solution H2O solution diluted Noah solution Noah solution The following graph contains the reaction rates of all the tests performed in this lab: Conclusion
Catalane had various changes in reaction rate when the pH, temperature, or enzyme me concentration were changed, supporting the hypothesis. The enzyme is affected by it’s sours ending environmental conditions. This lab showed that reusing the substrate did not produce a reaction. Reusing the catalane produced a reaction aqua I to the control. Different tissues showed the presence of catalane in differing quantities. Catalane denaturized when boiled and did not induce faster reacts on rates.
Catalane worked more efficiently in cold environments than in warm environments. Catalane worked faster in more basic environments. From the r exults gathered, the conclusion can be drawn that catalane is a reusable enzyme that works better in basic, cold environments and is denaturized when heated to o much. The measuring systems used were not very accurate, especially using p hysterical observations to measure the reaction rates. A person can be inaccurate a ND inconsistent in comparing reaction rates on a small scale like the one used.
The amount of catalane available for the reaction v aired with the size of the liver and how much surface area was available, so the a mount of catalane could not be regulated in every experiment. A machine or substance can be used to measure the react ion rate more precisely, possibly by measuring the rate oxygen is release De. The liver can be blended and measured in specific quantities or catalane can be extracted to regulate the amount of catalane being used. Literature Citation Cain, M. L. , Campbell, N. A. , Jackson, R. B. , Minority, P. V. Erect, J. B. , Airy, L. A. , and Wassermann, S. A. , 2010, An Introduction to Metabolic ism, Campbell Biology, San Francisco, CA: Benjamin Cummings. Questions Part A What gas is being released? Oxygen is being released. Has it gotten warmer or colder? The test tube has gotten warmer. Is the reaction endothermic or exothermic? The reaction is exothermic. What is this liquid composed of? The liquid is composed of water. What do you think would happen if you added more liver to this liquid? No reaction would occur. Is catalane reusable? Explain how you know.
Catalane is reusable because it isn’t used up in the reaction and reacted when used again. Part B Which tissues contained catalane? All three substances potato, apple, and chicken liver contained catalane. Do some contain more catalane than others? How can you tell? Some contained more catalane than others because SE the reaction rate was faster, so more catalane as present. Part C What will boiling do to an enzyme? Boiling an enzymes will denaturized it, or make it unusable by altering its shape. Part D What is the optimal pH for catalane (estimate)?
The optimal pH for catalane is approximately y 8 because it worked best in a weak base. Part E Using the techniques you learned in this lab, design a n ewe experiment to test the properties of enzymes and substrates. Add 2 ml of hydrogen peroxide to a clean test tube. Place this test TU be in a boiling water bath for 5 minutes. Using the test tube holder, r move the test tube from the hot water bath. Add a piece of liver. Record the reaction rate. Data Analysis Describe the relationship between catalane and hydro gene peroxide.
Indicate which is the enzyme, which is the substrate and what occurs during the reaction. Catalane (enzyme) speeds up hydrogen peroxide ( substrate) breakdown. The hydrogen peroxide interacts with catalane, causing faster breakdown into water and oxygen. Is catalane reusable? Use data to support your answer. Catalane is reuse able because one liver was used to speed up two different reactions. How does temperature and pH affect the reaction rate of catalane? Cold water and basic solutions increase the rat of the reactions, while warm water and acidic solutions slow the reaction rate.