Enzyme Test Lab Report

Improved Essays
For the first part, the qualitative polyphenol oxidase test (Table 1), we looked at 3 qualitative test tubes, where only test tube 2 turned orange since this tube had both the 40 mM dopa, the substrate and PPO enzyme extract. However, the test tube 3 did have a cloudy component because of the presence of PPO extract, but there was no color change. For a color change to occur, there needs to be a presence of both the dopa and PPO extract. Furthermore, we calculated the final concentrations of dopa using the C1V1=C2V2 formula for the control groups (test tubes 1,3,5,7) which was 0mM and the experimental groups (test tubes 2,4,6,8) which was 4mM (Table 2). A standard curve of dopachrome concentrations vs. absorbance at 475nm was generated …show more content…
Based on our experimental results, we can conclude that our hypothesis is correct (Graph 2). To further explain, there is a greater amount of the enzyme available for the dopa to interact with and will lead to more formation of dopachrome. The rate of the enzyme-catalyzed as measured by velocity, also showed a linear relationship (Graph 3) and the enzyme being a limiting reactant, so the reaction will proceed at a maximum velocity. When the substrate in in excess, more enzyme will produce more product at a higher rate since Vi will be equal to Vmax. However, the linear relationship will not hold if the dopa becomes the limiting reagent. In the Qualitative polyphenol oxidase test (Table1), only one of the three reactions formed an orange product. The orange product is formed because of production of dopachrome. For dopachrome to be produced, both the substrate (dopa) and PPO enzyme must be present. The reactions that only contained one of the two hence will not produce dopachrome. With just PPO, and no dopa, there is no substrate for the enzyme to catalyze, and therefore no color change will take …show more content…
However, looking at the r-squared values of Graph, 1 2 and 3, it shows a strong positive correlation since it is closer to 1 between the two variables. To further the study the effect of enzymatic browning, this is an essential component. In this lab, we study the conversion of the substrate dihydroxyphenylalanine (dopa) to dopaquinone quickly converted to dopachrome in the presence of oxygen. It is interesting how the direct product of dopa, dopaquinone was never really measured and neither was PPO extract enzyme. Furthermore, the differences between the dilution factors 1/5 to 1/10 was a factor of ½ similarity to 1/20 and 1/40 as displayed on the graphs. This might be due to collisions between the molecules. Since temperature plays a huge role by affecting the shape and activity of enzyme, it must be kept higher for the enzyme to not cause denaturation. During this lab, the enzyme was always kept in the ice-cold bath. Similarity, people put most fruits and vegetables in the fridge. Thus, putting cut open potatoes in a refrigerator would help keep PPO active and prevent enzymatic browning. In addition, Enzymes are controlled by two different types of inhibition; competitive and non-competitive. Competitive inhibition occurs when inhibitors compete with the enzyme substrate to bind to the active site. While Non-competitive inhibition is when the inhibitor binds to the active site that

Related Documents

  • Improved Essays

    What predictions would you make about the enzyme activity if you were to continue to change each of the factors in Parts A – E? The predictions that would be concluded about the enzyme activity if it were to continue and change each of the factors in Parts A – E, would be that enzyme activity will decrease due to the optimal temperature, pH, concentrations, and metal salt concentration not being obtained. How does changing the concentration of enzyme affect the rate of decomposition of H2O2?…

    • 680 Words
    • 3 Pages
    Improved Essays
  • Improved Essays

    Rg's Ischaemic Case Study

    • 528 Words
    • 3 Pages

    The dose given at 3mcg/kg/min which is in the range of 1-5 mcg/kg/min IV (low dose) may increase urine output and renal blood flow. 8mcg/kg/min is in the range of 5-15 mcg/kg/min IV (medium dose) may increase renal blood flow, cardiac output, heart rate, and cardiac contractitlity. Duration of onset is 5 min while duration of absorption is less than 10 minutes. Volume of distribution is 1.8 to 2.45L/kg. Dopamine is metabolized in liver, kidney, and plasma by monoamine oxidase and catechol-O-methyl transferase, convert it into active norepinephrine and inactive metabolites.…

    • 528 Words
    • 3 Pages
    Improved Essays
  • Improved Essays

    Peroxidase Lab Report

    • 450 Words
    • 2 Pages

    The hypothesis was proven wrong by the timing and values of the graph. I believe this was caused by the enzyme having to break apart a heightened amount of substrates in the mixed test tubes. This caused the initial data to yield a quicker reaction (on the basest of browning in color) compared to the altered data. The independent variable of this experiment was time, while the dependent variable was the color as the reaction is completely dependent on the duration of time. There were numerous potentially sources of error during this experiment.…

    • 450 Words
    • 2 Pages
    Improved Essays
  • Improved Essays

    INTRODUCTION: The objective of this lab is to measure the activity of an enzyme and the effects of environment conditions on enzyme activity. Enzymes are catalysts; agents that speed up chemical reactions by lowering the activation energy required. This means that a catalyst helps reactions occur at a greater speed and lower temperature.…

    • 449 Words
    • 2 Pages
    Improved Essays
  • Great Essays

    Peroxidase Lab Report

    • 1615 Words
    • 7 Pages

    Nine tests tubes were used for the effects of temperature and effects of pH on the enzyme activity. Mixing two tubes at a time at four different temperatures and recording the absorbance given in twenty-second intervals found the effects that temperature and pH has on peroxidase. Tubes 2 and 3 were tested at 4°C, tubes 4 and 5 were tested at 23°C, tubes 6 and 7 were tested at 32°C and tubes 8 and 9…

    • 1615 Words
    • 7 Pages
    Great Essays
  • Improved Essays

    Tyrosinase Lab Report

    • 369 Words
    • 2 Pages

    It transforms the amino acid tyrosine to the compound dopaquinone. Then dopaquinone is converted to melanin in the hair follicles, skin and the retina. Tyrosinase is also responsible for the brown color that forms on the inside of fruits and vegetables after they have been cut. The tyrosinase catalyzes the reaction with oxygen and catechol. Catechol is an organic alcohol found in most plants.…

    • 369 Words
    • 2 Pages
    Improved Essays
  • Improved Essays

    Liver Lab

    • 544 Words
    • 3 Pages

    The difference between the two graphs is the speed of the reaction. The temperatures of the two tests were very similar throughout the experiment. when doing this experiment one should have a paper towel ready to wipe the side of the test tube to be able to read the temperature. Conclusion: This experiment tested the difference between a untreated and treated catalase enzyme.…

    • 544 Words
    • 3 Pages
    Improved Essays
  • Decent Essays

    In most cases, a chemical reaction is able to occur in more than one way; enzyme kinetics studies the effect of how biological catalysts can influence biochemical reactions. Enzymes play an important role in regulating metabolic pathways in the human body and without enzymes they will not function efficiently. The rate of a reaction is enhanced by enzyme activity which provides alternate pathways for the reaction to proceed by.…

    • 177 Words
    • 1 Pages
    Decent Essays
  • Superior Essays

    Amylase Biology Lab Report

    • 2820 Words
    • 12 Pages

    The Effect of Change in Temperature Conditions on Enzymes Bacillus licheniformis Amylase and Aspergillus oryzae Amylase Over Time ____________________________________ Roxanna Flores PID: 5199946 Lab Section U26 Group Members: Roudabyna Taleb Abstract This laboratory was performed in order to be able to determine the effect of temperature over time on bacterial amylase Bacillus licheniformis and fungal amylase Aspergillus oryzae. Bacterial amylase was introduced into four singular test tubes at different temperatures. A starch solution was added to each to be able to observe the behavior of the enzyme.…

    • 2820 Words
    • 12 Pages
    Superior Essays
  • Decent Essays

    Peroxidase Lab Report

    • 204 Words
    • 1 Pages

    In this experiment the effects of the peroxidase enzyme will be observed. Peroxidase is an enzyme that is largely contained in turnips, horseradish roots, and potatoes. This enzyme rids cells of peroxide forming water and oxygen. Peroxidase also aids in the oxidation of guaiacol into tetraguaiacol. The peroxidase (turnip extract) and substrate guaiacol will be mixed and the reaction rates will be monitored under the different conditions.…

    • 204 Words
    • 1 Pages
    Decent Essays
  • Superior Essays

    Albumin Synthesis

    • 1183 Words
    • 5 Pages

    Through this experiment we measured how fast a chemical reaction occurs, by changing the degradation rate in Albumin when added to different enzymes. Albumin is a protein found in egg white, which is considered to have important storage and nutritional functions. Albumin has also been used in medicine to treat heavy metal intoxication. We ran Albumin through four different conditions to see which would make the Albumin degrade faster. We predicted that the Albumin would degrade with pepsin the fastest since it is essential for digestion of substances in the stomach.…

    • 1183 Words
    • 5 Pages
    Superior Essays
  • Improved Essays

    The purpose of conducting this experiment was to explore how different factors affect the reaction rate of enzymes reacting with their corresponding substrates in order to learn more about how enzymes function in different environments. The independent variables investigated in this experiment were the concentration of different substrates, the temperature of the environment, and the effect of a catalyst on the reaction rate. The dependent variable for all of the investigations was the time it took for the reaction to occur. To investigate the effect of the concentration of the substrate on the reaction time, four test tubes were used.…

    • 1027 Words
    • 5 Pages
    Improved Essays
  • Improved Essays

    Many factors can affect the enzyme activity (including temperature, pH, substrate concentration), so all conditions apart from the one being quantified should be standardised. The…

    • 1627 Words
    • 7 Pages
    Improved Essays
  • Improved Essays

    Introduction: Enzymes have a huge effect on the human body and other organisms. Enzymes are catalysts that are used to accelerate the reaction process by lowering the activation energy. For this experiment the catechol oxidase was extracted from potatoes. The enzyme is called catechol oxidase because the oxygen is reacting to catechol. Catechol oxidase causes the browning of the fruits and vegetables because the compound is toxic to the bacteria.…

    • 1142 Words
    • 5 Pages
    Improved Essays
  • Superior Essays

    Potato Catalase Analysis

    • 692 Words
    • 3 Pages

    Explain the results you obtained using a piece of muscle and a piece of potato?. Both the test tubes will show decomposition of hydrogen peroxide because both potato and uncooked ham have catalase enzymes. 5. What effect did acetic acid (vinegar) have on the reaction?…

    • 692 Words
    • 3 Pages
    Superior Essays