Enzyme Lab Report
The major objective of this experiment was to observe the effects of catalase under varying controlled conditions. The scope of this experiment includes Metabolic processes, such as cellular respiration, and it poisonous byproduct hydrogen peroxide. The methodology includes procedures; multiple variables were tested in specific concentrations; that test the reaction rates of the enzyme catalase over a fixed period of time.
The major conclusion was that catalase reacts faster in warm temperatures that are neither freezing nor boiling, catalase performs well in lower concentrations than the substrate, and catalase prefers neutral pH levels around 7. Introduction Enzymes are proteins that catalyze metabolic reactions vital for the survival and functioning of cells . Without enzymes, metabolic processes would occur at unfeasible rates. Catalase is a naturally occurring enzyme that breaks down hydrogen peroxide into water and oxygen; it is essential to cellular respiration.
I asked if enzyme activity was affected when exposed to different conditions, such as temperature, substrate concentration, and pH levels. My first hypothesis is that higher temperatures amplify catalyzation, although too high of a temperature denatures enzymes. My second hypothesis is that smaller concentrations of enzyme in the enzyme to substrate concentration ratios produce higher reactions. The last hypothesis is that enzyme reactions work best at a neutral pH. I observed and recorded the effect of these conditions on catalase.
The enzyme catalase is important because it handles the decomposition of approximately half of generated H2O2 in living organisms . It is important for biologists to understand catalase because all cells produce hydrogen peroxide, and its the job of catalase to break it down. This research will help increase the knowledge of enzyme activity in complex environments, and under what conditions the enzyme catalase will perform best. Materials and Methods.
The materials used in this experiment included 4 test tubes (5 for pH), atalase, hydrogen peroxide, an ice water bath, a warm water bath, a boiling water bath, thermometer, test tube rack, a wax pencil, a metric ruler, a timing device, and pH solutions at 1, 4, 7, 10 and 13. Three different experiments were tested in this lab; temperature, substrate concentration and pH. In the temperature experiment, I filled all 4 test tubes with 3 centimeters of hydrogen peroxide and 2 centimeters of catalase, and then labeled them 1) Room Temperature(20°C), 2) Ice(0°C), 3) Body Temperature(37°C), and 4) Boiling(100°C).
The positive control of this experiment was the test tube kept in room temperature, and the negative control was the test tube placed in the ice. The independent variables of this experiment were time and temperature, and the dependent variable was the amount of reaction that occurred. Each test tube was left at the designated temperature for two minutes, and then afterwards were tested every ten seconds for a minute. My technique included swirling the test tube 3 times each after every ten seconds, and then I would record the bubble height in centimeters.
In the Substrate concentration experiment, I filled the test tubes with different enzyme to hydrogen peroxide concentrations, which were measured in centimeters. Next, I labeled the test tubes accordingly; 1) 1(cm):4(cm), 2) 2:3, 3) 3:2, and 4) 4:1. The positive control of the experiment was the test tube with the 1:4 ratio of enzyme to substrate concentration, and the negative control was the 4:1 ratio of enzyme to substrate concentration. The independent variables were time and the ratio of enzyme to substrate concentration and the dependent variable was the amount of reaction that occurred.
Each test tube was left at room temperature and then tested every ten seconds for a minute. The technique used was the same as experiment one. In the pH experiment, I filled all 5 of the beakers with 2 centimeters of Catalase and 3 centimeters of hydrogen peroxide. Afterwards, I labeled the beakers 1) pH 13, 2) pH 10, 3) pH 7, 4) pH 4, and 5) pH 1, and then added the pH solutions accordingly. The positive control was the pH 4 test tube, and the negative control was the pH 13 test tube. The independent variables were time and pH levels, and the dependent variable was the amount of eaction that occurred. Each test tube was left at room temperature for one minute and then tested every five seconds for thirty seconds.
The technique used was also the same as the first experiment. Results Figure R. 1 In figure R. 1, the test tube stored at body temperature reacted the fastest, and the test tube that was boiled had no reaction, because the enzyme was denatured. This supports my hypothesis that higher temperatures amplify catalyzation, although too high of a temperature denatures enzymes. Figure R. 2 In figure R. , the two highest reactions were the 1 to 4 ratio and the 2 to 3 ratio, this is because the amount of catalase added to the substrate was enough to cover the reaction. The lowest reaction was the 4 to 1 ratio, this is because the 3 to 2 and 4 to 1 ratios, too much catalase was added. The catalase broke down all the hydrogen peroxide and then had a surplus after the reaction occurred.
This supports my hypothesis that smaller concentrations of enzyme in the enzyme to substrate concentration ratios produce higher reactions. Figure R. 3 and R. 4 Figure R. 3 contains the recorded data of the effect of pH on enzyme reactions. Figure R. is the graph of the recorded data; it shows that the most reaction occurred at a pH of 7, this is because catalase works optimally at that pH. The least reaction occurred at a pH of 13 because it is too basic for catalase, and it works independently from basic pH levels. This supports my hypothesis that enzyme reactions work best at a neutral pH of 7. Discussion Principles, Relationships, and Generalizations.
The principles of this experiment were that 1) higher temperatures amplify catalyzation, although too high of a temperature denatures enzymes, 2) smaller concentrations of enzyme in the enzyme to substrate concentration atios produce higher reactions, and 3) enzyme reactions work best at a neutral pH. The correlation between these three principles is that they all speed up the process of enzyme activity. The basic generalization made is that enzymes are extremely efficient. Enzymes are biological catalysts that can speed up, and control, chemical reactions that would otherwise virtually never occur at normal body temperature. Thousands of chemical reactions are occurring in the human body every moment of life, and each of these reactions is controlled by a particular enzyme .
Comparing Results Considering my experiments and data, my end result was the exact criterion I originally expected. The results assembled clearly supported all three of my hypotheses. Compared to the Catalase Lab, conducted by Gen Nelson, the results are reflected almost exactly. The same exact procedures and materials were used, but the dependent variables were measured in different concentrations. The general results matched my results. The Big Picture The significance of my work is to demonstrate efficiency of catalase.
Hydrogen peroxide is a toxic byproduct of metabolism that can destroy cells if it is not removed. It adds understanding to the success of cellular respiration and how the hydrogen peroxide is decomposed. Without catalase, cells would commit suicide due to the high concentration of hydrogen peroxide in the cells; also it would create lesser amounts of oxygen and water in metabolic reactions because catalase handles the decomposition of approximately half of generated hydrogen peroxide in living organisms. This would also halt the metabolic processes inside the cell.
Suggestions for future work would be to test how the enzyme catalase is able to function in extremophiles and mesophiles, because of their extreme conditions. This research should take a professional and informational stance, such as helping the general public, as well as other scientists comprehend how bacteria are able to survive in their complex environments. Conclusion Overall, my hypotheses were supported by my results. This means that catalase reacts faster in warm temperatures that are neither freezing nor boiling.
This conclusion also means that catalase performs well in lower oncentrations than the substrate. Lastly, it also concludes that catalase prefers neutral pH levels around 7. Summary This experiment tested the reaction of the enzyme catalase under different conditions. The main findings were supportive of my hypotheses. The significance of these experiments can be best described as informational data that informs young scientists as well as the general public. This needs to be known to understand metabolic reactions and its poisonous byproducts, as well as what decomposes the byproducts.