2B) The purpose of this part of the lab was to determine the amount of hydrogen peroxide (H2O2) initially present in a 1.5% solution. We were testing the concept of establishing a baseline without adding catalase (enzyme) to the reaction mixture. The dependent variable is the hydrogen peroxide (H2O2), water, and H2SO4. The independent variable is the amount of KMnO4 used in the burette to get the solution a persistent pink or brown color.
This lab deals with enzymes, catalyze, and the reaction of the two together. Enzymes are proteins produced by living cells, and a catalyst is a substance that speeds up the reaction and lowers reaction energy. Enzyme catalyst connects to a site of an enzyme, lowering the amount of energy required to produce a reaction with the substrate.In this experiment we used the titration method to determine the quantity of substances in many different types of solutions.This experiment will help us to observe how catalyst enzymes work to speed up the reactions and turn hydrogen peroxide into water and oxygen gas. By letting these reactions take place for different amounts of time, we could compare and contrast which conditions and time limits cause more of a reaction and which cause less. WE LOVE ENZYMES!!!! :)
2B) We tested a baseline as a comparison for the experiment. We mixed water, hydrogen peroxide, and sulfuric acid. After removing a 5 mL sample of the mixture and added KMNO4 until the pink color remained visible in the liquid.
2C) We had 7 different cups labeled with 7 different times (10, 30, 60, 90, 120, 180, 360 seconds). In each cup we put the same amount of hydrogen peroxide, yeast, and acid; however, after adding the hydrogen peroxide and yeast, we controlled the amount of time we let the reaction take place. In order to stop the reaction we added sulfuric acid after a specific number of seconds. The times listed on the cups represented the amount of time we let the yeast and hydrogen peroxide react. Then, we removed a 5 mL sample and added KMNO4 until the pink color remained visible in the liquid. The longer we let the reaction take place, the less KMNO4 was needed in order to make the color stay.
|Data from part 2C|
|Data used from part 2C|
2B) In this experiment the level of KMnO4 the burette dropped from 27 ml to 24 ml. This means that the level of KMnO4 dropped 3.1 ml. These results are important because the baseline is used in every experiment. The baseline is used too test the amount of H2O2 in a 1.5 solutions.
2D) In this experiment we tested the same reaction as the last experiment but instead of no enzyme we added enzymes to the experiment. In this experiment we see that as time progressive the enzymatic rate lowered. The highest rate is the first in the first time interval (0-10) . It was the highest because iit had the highest catalysis amount and the most amount of H2O2 to decompose. The lowest rate was the last time interval (180 -360) there are 2 possible reason why it is the lowest. One is the H+ content makes the solution more basic. This moves the solution away from its optimal ph, thus causing the enzyme to denature. Denaturing is when the enzyme becomes biologically inactive because the proteins begins to unfold. Another reason could be is that all the catalysis amount is at the lowest because all the enzymes are already being used. This causes an inhibiting effect on reaction. Inhibiting is when the reaction is stopped or slowed down. If we were to lower the temperature it would still cause the enzyme to denature. Like ph, enzymes also have an optimal temperature if the temperature gets too low or too high it will denature.
By performing this experiment we were able to determine the quantity of a substance in different solutions through the titration method. We also recorded the rate of how quickly the catalsye enzyme was able to convert Hydrogen Peroxide to water and oxygen gas, which helped us expand our knowledge of the importacne enzymes and how they function.
|Yeast- catalyst used to start the reaction|
|Color of solution after being titrated|
|All the solutions being set up to be timed with the catalyst|