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Enzyme Activity Lab Hypothesis: 1] Are enzymes reusable? Yes, enzymes are reusable. 2] Which of the following do you think contain catalase? [Manganese dioxide, chicken meat, apple, carrot, potato, or chicken liver] I think that the manganese dioxide, apple, and carrot contain the catalase. 3] Would grinding the materials affect enzyme activity? I think that grinding the materials will increase enzyme activity. 4] Would temperature affect enzyme activity? I think that at normal body temperature, regular enzyme activity will occur. 5] What about pH levels?
I think that at a balanced pH level (pH 7) like water, enzyme activity will be at the highest. Objectives: -To demonstrate the activity of an enzyme in living tissues -To learn how changes in temperature and pH affect the activity of a catalase -To experimentally test for the presence of catalase in living tissue -To analyze factors affecting enzyme activity -To determine the affect of particle size on enzyme activity Materials: 3% Hydrogen PeroxideScissors Straight-edge razor blade10 Test Tubes Mortar and PestleBlender/Food Processor Test Tube RackDistilled Water PipetteGoggles Manganese DioxideStirring Rod
Fresh Chicken MeatForceps Fresh AppleThermometer Fresh CarrotIce bath Hot PlateFresh chicken liver Conclusion: In this lab, we were able to observe the affect that catalase has on different substances such as pieces of liver, chicken, apple, potato, and carrot. In the experiment, if the substance started to create bubbles, then it contained the catalase that could break down the hydrogen peroxide or H2O2. The reaction between liver and hydrogen peroxide or H2O2 was an exothermic reaction. After having reacted, the liver and hydrogen peroxide or H2O2 mixture caused the temperature to rise.
When heat is being released from a reaction it is caused exothermic. In the body hydrogen peroxide or H2O2 is separated and oxygen and water are released into the body. Thus, the reaction gives the body hydrogen peroxide or H2O2 and oxygen, two essential needs for the human body, from something that could possibly poison or kill your body. Although there were excellent reactions, there were several conditions that slowed down and stopped the action of the enzyme catalase. One condition was when the liver was boiled. The liver hardened and it did not react to the hydrogen peroxide or H2O2.
Also, when reused hydrogen peroxide or H2O2 was used, there was not a reaction. Catalase has an optimal temperature and pH for that of a human cell. The optimal temperature is average room temperature, which is about 25??C. With the class averages, it had the highest rate of reaction with a 3. 38. Also, the optimal pH was a neutral one of 7. By comparing this to the class data, ph 7 had a rate of reaction over 4, giving it the highest rate of reaction of all the pH levels tested. These pH and temperature levels are good because in the human body, there is a low pH and a constant body temperature.
When the temperature is changed, either lower or higher, the enzyme activity is greatly affected. When the liver was boiled, there was a little to no reaction. Also, with different pH levels, catalase acts very differently. The difference between the acidic pH levels and base-like pH levels were very different. In the lab, we were able to determine which tissues had catalase present. All of the tissues appeared to have catalase present in them. Although is seemed that all the tissues contained catalase, they did not have the same amount or quantity of it.
The tissue with the lowest rate of reaction, a rate of . 52, was the piece of apple. The tissue with the highest average rate of reaction was liver. Liver had an average rate of reaction of 3. Because the body creates so many deadly poisons, catalase needs to be present in order to speed up the rate of reaction. The liver and the hydrogen peroxide or H2O2 reacted through hydrolysis. The hydrogen peroxide or H2O2 was separated by taking out the water that bonded it. The gas that was produced was O2 or oxygen. One can tell that O2 or oxygen was produced because it the only gas the supported burning.
When the class did the demo, the splint stayed lit in the test tube, proving that oxygen was present. The liquid that was left behind was H2O better known as water. When hydrolysis took out the oxygen in the bond, the only thing that was left was H2O2. The group data compared to the class averages weren’t that different. To start with, the used hydrogen peroxide or H2O2 with the new liver were off. The rate of reaction that the group gave was a 1 while the class average was . 25. This might have happened by not pouring all of the used hydrogen peroxide or H2O2 into the new test tube with the new liver.
Also, the warm liver and hydrogen peroxide or H2O2 varied by a 2. 33 difference. This may have occurred by not having a constant temperature of 25??C. Another big difference that we had was with the hydrogen peroxide/ H2O2, liver, and acid pH3. Our group data showed that we had given the rate of reaction a 3 while the group data’s average was a 1. 63. I think that when we performed this part of the lab, we may have not fully used 2 mL of H2O2 because we getting close to the end of the lab and we decided to use as much of it as we could of without having to open another bottle.