Catalase Lab Report Example
Introduction
Enzymes are proteins found in many organisms that act as a catalyst for important chemical reactions. Without these various enzymes, important chemical reactions would happen at too slow a rate for life. For example, humans would not be able to digest food because it would take too long. The food that the human ate would go through the digestive system before the body was able to get any important nutrients from it. Different factors affect enzymes, such as temperature and pH level. Depending on how out of order or in order temperature or pH is, it could slow down or speed up the chemical reactions that enzymes cause. If temperature or pH is too irregular, an enzyme could become denatured. This means that the interactions that hold the proteins together in an enzyme become disrupted, and the three-dimensional structure of the enzyme unfolds, meaning the substrates will not fit into it anymore. During a chemical reaction, a substrate will couple with the enzyme in its active site, where the chemical reaction takes place. After the chemical reaction takes place, the products will have been formed, the products then leave the active site, and the enzyme is ready to take in another substrate and complete the whole process again. Catalase is an enzyme, it catalyzes a chemical reaction with its substrate H2O2 (Hydrogen Peroxide), a toxin in your cells. Catalase is important to your body because if it was not present, hydrogen peroxide would cause harm to cells in your body. Catalase catalyzes a reaction with hydrogen peroxide, which decomposes it into water and oxygen. The reaction is as follows- 2 H2O2 → 2 H2O + O2. In this lab, the group will be placing spheres of yeast into hydrogen peroxide to test for the presence of catalase. If catalase is present, it will catalyze a reaction with the H2O2, which will turn it into water and oxygen, causing the spheres to rise to the surface. This same test will also be completed at various temperatures to determine which is optimum for the catalase enzyme. This will be done by comparing the time that it takes for the spheres to rise to the surface while taking into account the varying temperatures. The hypothesis of the group is that room temperature (about 23°C) would allow for the catalase to have the fastest reaction rate. This is because room temperature is in the middle, it is not too hot nor too cold for the enzyme. The group also hypothesized that the hot water bath (about 45°C) would cause the catalyst to have the slowest reaction rate (or to not react at all) because hot temperatures are more likely to destroy something than cold temperatures.
Materials
Material
Quantity
Function
Yeast
spheres
10
The group will test this to determine if the enzyme catalase is present.
H2O2
50ml of .3% H2O2
The substrate will react with the catalase if it is present.
Incoluating Loops
1
Will be used to move the yeast spheres.
Waste cup
1
Used to put waste in.
Water bath
1
The yeast will be bathed in this before being placed in H2O2
Ice bath
1
The yeast will be bathed in this before being placed in H2O2
Design set up
Catalase lab setup
The yellow stick is the inoculation loop, which is used to transfer the yeast spheres into the graduated cylinder. The graduated cylinder is in the middle, it is filled with hydrogen peroxide, which will react with the catalase (if it is present) in the yeast spheres. The square bowl in the bottom left corner is filled with a calcium chloride solution, which has the yeast spheres in it, the spheres can be seen in the bowl, they are a sort of off-white color.
Procedure
#1 Place the Yeast sphere into the graduated cylinder filled with H2O2
#2 Wait for the catalase to react with the H2O2
#3 Take out the yeast sphere and place it into the waste cup
#4 Record data
#5 start trial 2 with the remaining yeast spheres, place the yeast sphere into the graduated cylinder filled with H2O2
#6 Wait for the catalase to react with the H2O2
#7 Take out the yeast sphere and place it into the waste cup
#8 Record data
#9 Start trial 3 with the remaining yeast spheres
#10 Place yeast into the graduated cylinder
#11 Wait for the reaction to take place
#12 Take yeast out of the cylinder and place into the waste cup
#13 Repeat the steps
Data and Analysis
Table 1: Groups individual data, and average.
This data table represents the data from the lab, it describes the type of treatment, how many trials took place, the time in seconds that each yeast sphere took to sink and rise, and the average time in seconds for all trials.
Table 2: Data for the whole class (all groups): Average time for Yeast Spheres to sink and rise
Cold Group 1
( 4℃)
Room Temperature Group 1
(22℃)
Hot Group 1
(69℃)
58.22 seconds
18.02 seconds
4 seconds
Cold Group 2
(4℃)
Room Temperature Group 2
( 23℃)
Hot group 2
(69℃)
92.8 seconds
16.231 seconds
5.31 seconds
This data table represents the data, average time for yeast spheres to sink and rise, and types of treatments, of all groups in the class.
Graph of all data from class
The graph above is a summary of all of the average times for the yeast spheres to sink and rise at different temperatures. It can be seen in the graph that the hotter temperature was, the faster the catalase catalyzed a reaction with the H2O2 in order to create oxygen and water, causing the yeast spheres to rise. When the temperature was a cool 4°C the reaction took an average of 76.01 seconds to take place. When the temperature was a normal temperature of 22°C or 23°C (roughly room temperature) The reaction rate was quicker than the rate than it was when it was cold, the reaction rate at this temperature was on average 17.0205 seconds. The temperature was then increased to a high of 69°C, this caused the reaction rate to increase largely again, the average time for the reaction to happen with this temperature is an average of 4.655 seconds to happen. It is a clear trend that the hotter the temperature is, the quicker a reaction with catalase and H2O2 happens, this may be because the hotter the temperature is, the quicker particles (such as enzymes and substrates) move around, causing there to be a higher likelihood of an enzyme and substrate colliding.
Conclusion
In conclusion, the purpose of this experiment was to test for the presence of the enzyme catalase by putting small spheres of yeast into a .3% hydrogen peroxide solution. The experiment also tested how the rate of reaction changed at different temperatures. The group hypothesized that room temperature (about 23°C) would allow for the catalase to have the fastest reaction rate. The group also hypothesized that the hot water bath (about 45°C) would cause the catalyst to have the slowest reaction rate (or to not react at all) because hot temperatures are more likely to destroy something than cold temperatures. Based on the results of the experiment, the group decided to reject the original hypothesis as it was incorrect. The group hypothesized that the hot temperature would yield the slowest reaction, however, it was the exact opposite. The reaction was the quickest when the temperature was hot, the reaction rate took an average of 4.655 seconds in the hot temperature. The group also hypothesized that the room temperature would be the quickest because it was in the middle, this was also incorrect, and so has been rejected. The results of the experiment showed that the enzyme catalase was indeed present in the yeast spheres. The group can tell that this is true because the yeast spheres catalyzed a reaction when placed in the hydrogen peroxide, which caused the decomposition of the H2O2 into water and oxygen gas which in turn caused the yeast spheres to rise to the top. The data collected during the experiment also showed that a cold temperature (4°C) causes the catalase to react at the slowest rate out of other temperatures with the reaction taking an average time of 76.01 seconds, room temperature did not cause the fastest or slowest chemical reaction time but was in the middle with the reaction taking an average of 17.0205 seconds, and the hot temperature caused the fastest reaction with the reaction taking an average of just 4.655 seconds. No modifications were made to the original procedure. There were some limitations, such as the people who followed the procedure were not trained scientists, which would make human error much more common, because the group had less experience in this field. Enzyme reactions are very important to life, because many enzymes create vital reactions that life would not be able to exist without. For example, there is DNA polymerase, an enzyme that synthesizes DNA, which is extremely important for life, and life would not exist without it (Britannica, 2021). A
References
Kornberg, Hans. "metabolism". Encyclopedia Britannica, 5 Nov. 2021, https://www.britannica.com/science/metabolism. Accessed 3 December 2021.
