Enzyme lab report

.docx

School

University of Alabama, Birmingham *

*We aren’t endorsed by this school

Course

123

Subject

Biology

Date

Apr 3, 2024

Type

docx

Pages

Uploaded by MagistrateElectron9761

Miller 1 “The Effect of pH, Temperature, Enzyme, and Substrate Concentration on the Enzyme Activity of Catecholase” BY 123L-B4 Gage Miller

Miller 2 Introduction: All living organisms use chemical reactions to stay alive. Metabolic reactions can occur in living organisms, but they happen too slowly to sustain life (Campbell, 2020). Enzymes can be used to help speed up these reactions. Enzymes are organic molecules, with one or more polypeptide chains, that lowers the activation energy which contributes to speeding up the reaction process (Bluedoor, 2019). All enzymes have an active site to which a substrate binds to. The shape of the substrate and the active site are similar, people often compare it to how a key fits a lock or how puzzle pieces complement each other. There are several factors that affect the shape of the active site which in turn causes the enzyme to react in many different ways. When the substrate binds onto the active site, the reaction speeds up and products are created, then the enzyme goes back to its original condition and is free to react with another substrate (“Enzymes and the Active Site”). Enzymes can work on many different pH and temperature levels; however, they do have optimal values for both pH and temperature. The rate of reaction can also change depending on the concentration levels of both the enzyme and the substrate (Bluedoor, 2019). Additionally, if they are not at their optimal value for pH or temperature. Then there is a possibility that the protein loses its tertiary or secondary structure and breaks down, this is known as denaturing (Bluedoor, 2019). When the temperature is raised, so does enzymatic activity, increasing the number of collisions between enzymes and substrates. When temperatures reach about 40 degrees Celsius, the enzymes start to denature (“Enzymes and the Active Site”). Changes in pH can affect the enzyme and make it hard for the substrate to bind to it. Enzymes work best within a certain pH range, but extreme acidic or basic

Miller 3 values can cause the enzyme to denature (“Enzymes and the Active Site”). When enzyme concentration rises there will not be enough substrates to bind to them causing them to become a limiting reactant. However, if substrate concentration is increased then the rate of enzymatic activity will increase until the enzymes cannot hold anymore substrates (Bluedoor, 2019). The purpose of this experiment is to perceive how these four factors affect catecholase. Hypothesis: Temperature: The original hypothesis is that if temperature increases, then the catecholase reaction increases. If temperature decreases, then the catecholase reaction decreases. The null hypothesis is temperature change will not affect enzymatic activity. The alternate hypothesis is that there will be an optimal temperature where the enzyme activity will peak. Decreasing at temperatures that are above or below the optimal temperature. pH: The most optimal pH value for enzymes is around 6-8. The enzyme will start to denature if it goes beyond these values. The original hypothesis is if pH increases, then the catecholase reaction rate will increase. If pH decreases, then the catecholase reaction rate will decrease. The null hypothesis is that pH will not affect the enzyme performance. The alternative hypothesis is that there will be an optimal pH at which the enzyme activity peaks and then decreases when the pH level is above or below the optimal level. Substrate concentration:

Miller 4 The primary hypothesis is that substrate concentration will only increase the speed of the reaction to a certain point until it reaches its maximum. The null hypothesis is that increased substrate concentration will not affect enzymatic activity. The alternative hypothesis is that substrate concentration increases so does enzymatic activity, until it reaches its maximum. Enzyme concentration: The original hypothesis is that as enzyme concentration increases, then the catecholase reaction rate increases. If enzyme concentration decreases, then the catecholase reaction will decrease. The null hypothesis is that the rise in enzyme concentration will not affect enzyme activity. The alternative hypothesis is that as enzyme concentration increases so does the enzymatic activity until it reaches its maximum. Materials and Methods: The Effects of Temperature on Enzymatic Activity: Acquire three test tubes and add exactly 3 mL of pH 7 buffer to each of the three tubes. Label the first tube “10” and place the tube into an ice-water bath. The “10” stands for 10 degrees Celsius. This tests how enzymes function in cold temperatures. Label the second test tube “24” but keep the test tube at room temperature. The “24” stands for 24 degrees Celsius. This tests the effect of enzyme productivity at room temperature. Lastly, label the third test tube “50” and place it into a beaker of warm water kept at approximately 50 degrees Celsius. This tests for enzyme activity at an elevated temperature. Wait 10 minutes for the buffer in each test tube to reach equilibrium. While the 10 minutes is ticking, get two test tubes containing potato

Miller 5 juice and place one on ice at 10 degrees Celsius and the other in a warm water bath at 50 degrees Celsius. Get two more test tubes containing catechol. Place one on ice at 10 degrees Celsius and the other in a warm water bath at 50 degrees Celsius. Once the 10 minutes is up add 10 drops of catechol from a tube at the matching temperature to each buffer. Add 10 drops of potato juice at the correct temperature to each tube. Allow these tubes to stand for 5 minutes then shake the mixture several times during the 5-minute period. Record your results by indicating the intensity of the color in each tube. 0 indicates no color change, 1 indicates a slight color change, 2 indicates a moderate color change, 3 indicates a strong color change (Bluedoor, 2019). The Effects of pH on Enzyme Activity: Label five test tubes with the following pH values: pH 4, pH 5, pH 6, pH 7, pH 8, pH 9, and pH 10. These will serve as experimental tubes. Fill each experimental tube with 3 mL of the matching phosphate buffer. Add 10 drops of catechol and 10 drops potato juice to each tube. Cover the tube with Parafilm and invert several times to mix the contents then remove the parafilm. Observe any color changes or color intensity. Allow the tubes to stand for 3 to 5 minutes. Invert and mix each tube at 1-minute intervals. The intensity of color at a given pH of the enzyme catalyzed reaction of time will be proportional. Use observations on a scale of 0 to 3 where 0 indicates no color change, 1 indicates a slight color change, 2 indicates a moderate color change, 3 indicates a strong color change (Bluedoor, 2019). The Effects of Enzyme Concentration on Enzyme Activity:

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version