Factors Affecting Enzymes Reaction
Enzymes are proteins by nature that serve as catalysts in different biological reactions. In the biochemical reactions, they speed up various activities. Enzymes help the reacting molecules by accelerating the activity. A substance that makes a reaction occur faster is called a catalyst. By forming temporary bonds with the reacting molecules, it allows the required energy to produce. During the reaction, the catalyst can be used again and again since it was not permanently destroyed. The speed of a chemical reaction is affected by several factors, including temperature, pH, concentration of the enzyme, and concentration of the substrate.
In these lab tests, one learns how to successfully carry out an experiment in order to detect the specific changes of activity of enzymes under the influence of the aforementioned factors. The lab provides a researcher with a chance to use different lab equipment, such as digital thermometer and a stopwatch. There are also initial challenges associated with accuracy, but they are manageable. It is required to have a lab notebook in order to record all the results for analysis. Moreover, guessing is not acceptable in the tests. The results are determined by the results recorded in the lab notebook.
Materials and Methods
In the first lab, the following materials are needed to investigate the effect of enzyme concentration on enzyme activity: hydrogen peroxide, stirring rods, test tubes, distilled water, catalase enzyme. First, I prepared four tubes. I labeled them 1, 2, 3, and 4. Next, I added different amount of catalase to the tubes one at a time. To the four tubes, I added equal amounts of hydrogen peroxide. Then, I measured the height of the bubble column every 20 seconds and wrote the results in the lab notebook.
In the second experiment, the following materials are needed to test the effect of temperature on enzyme activity: hydrogen peroxide, catalase enzyme, stirring rods, test tubes, thermometer, tube heater, ice bath. To begin with, I checked the temperature of the enzymes in each of the tubes using a digital thermometer and recorded the findings in the lab notebook. Next, I added hydrogen peroxide to each of the tubes. Lastly, I measured the height of the bubble column every 20 seconds and recorded the results in the lab notebook.
In the third experiment, the following materials are required to observe the activity to a certain pH value: hydrogen peroxide, catalase enzyme, stirring rods, distilled water, hydrochloric acid (HCl), sodium hydroxide (NaOH), test tubes, pH-meter. I prepared five test tubes and labeled them 1 to 5. To each of the tubes, I added the same amount of catalase. To obtain different levels of pH, to each of the five test tubes I added different amounts of HCl and NaOH. Then, to each of the test tube, I added hydrogen peroxide in equal amounts. Next, I observed and measured the height of bubble column every 20 seconds writing the findings in the lab notebook.
After carrying out the three lab experiments, I observed rising and falling of bubble column. Thus, I was able to make my conclusions and prove my hypothesis. From the experiments, I was able to make the following observations. In the first experiment, the hypothesis was about increasing enzyme concentration increasing the rate of reaction; after the first 20 seconds where the catalase was 0ml, the volume of bubbles was also 0. Where the catalase was 1 ml, the volume of bubbles was 1.5 ml. At 2 ml and 3 ml of catalase, the volume of bubble column was constant, 2.5 ml.
The second experiment was aimed at determining whether increasing the temperature will speed up the rate of reaction. Initially, the test tube contained catalase with the temperature of 0° in Celsius, and the volume of the bubble column after 20 seconds was 1 ml. In the tube that contained catalase with the temperatures of 25°C, the volume of the bubble column increased to 2 ml. In the tube with the catalase temperature being 37°C, the volume of the bubble column increased to 1.5 ml. At 45°C, the volume of the bubble column decreased to 0 ml.
In the third experiment, it was necessary to determine whether the activity is connected to a particular pH value. In the test tube where the pH levels were lowest equating to 3, the volume of the column bubbles was 0.5 ml. At the pH levels amounting to 5, the volume of the bubble column amounted to 0.5 ml. When the pH levels were 7 and 9, the volume of the bubble column was highest, 2.5 ml; increasing the pH levels to 11, the volume of the bubble column decreased to 0.5 ml.
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Discussion and Conclusion
In the first experiment, there are four tubes with different amounts of catalase. Hydrogen peroxide is added to each tube while the records are written in the lab notebook. The reason for the volume of the bubble column being recorded at the interval of 20 seconds is to have enough data to compare afterward because some reactions are much faster than others. Hydrogen peroxide ions are decomposed to hydrogen and oxygen. From the results, it is evident that when the catalase is high, the volume of the bubble column is observed to be higher because there are more ions to be decomposed. This leads to the following conclusion: when the substrate is increased, the interaction with the enzyme became increased as well. This resulted in the hike of the volume of the bubbles implying the increase in the reaction rate. The opposite dependence is also true. Therefore, my hypothesis is confirmed.
In the second experiment, concerning the effect of temperature on the enzyme activity, the catalase enzyme was well-equilibrated to different temperatures before the beginning of the test because temperature was the independent variable in the experiment. The volume in the bubble column was increasing with temperature raised to 37°C which was optimum. A further rise in temperatures resulted in the absence of the bubble column. This experiment supports the hypothesis that, indeed, the enzymes convert substrate to product faster at optimal temperatures.
The third experiment was related to the effects of pH on the enzyme activity. From the data, it is evident that when the pH levels are increased, the volume of the bubble column rises as well. The pH level that amounted to 7 is optimum for the reaction. As the pH level was being increased, the activity dropped significantly, hence decreasing the volume of the bubble column. Therefore, the enzyme activity is influenced by pH concentration. At the optimal pH level of 7, the enzymes convert substrate the most quickly since the reaction is sped up. Thus, pH has an effect on ions since the acidity and the basis have carboxyl functional groups and amine functional groups respectively, and once altered, they affect the ionic bonds that actually help to determine the 3D-shape of the protein. This may lead to deactivation of the enzyme (Hochachka & Somero, 2014).
These experiments taught me the importance of lab tests. Various factors affect enzyme activity and their functions. Carrying out the experiments and handling different lab equipment are quite enlightening and interesting procedures. The experiments taught me how to prove a hypothesis by using notes in the lab notebook. I also appreciate the importance of keeping records and ensuring accuracy when carrying out experiments. Learning and practicing are vital in conducting different biological experiments.