Action Of Enzyme Catalase On Hydrogen Peroxide - Lab Report Example

Action of enzyme catalase on hydrogen peroxide The aim is to find out the effect of the enzymecatalase found in liver on hydrogen peroxide (H2O2) a poison.. Catalase is an enzyme present in the cells of plants, animals and aerobic (oxygen requiring) bacteria. It promotes the conversion of hydrogen peroxide, a powerful and potentially harmful oxidizing agent, to water and molecular oxygen. 2H2O2 to 2H2O + O2 Catalase also uses hydrogen peroxide to oxidize toxins including phenols, formic acid, formaldehyde and alcohols. H2O2 + RH2 to 2H2O + R (http://www.seps.org/cvoracle/faq/catalase.html) Catalase was one of the first enzymes to be purified to homogeneity, and has been the subject of intense study. The enzyme is among the most efficient known, with rates approaching 200,000 catalytic events/second/subunit (near the diffusion-controlled limit). (http://biology.kenyon.edu/BMB/Chime/catalase/frames/cattx.htm) Hydrogen peroxide is formed as a waste product of metabolism in many living organisms. It is toxic and must be quickly converted into other, less dangerous, chemicals. To manage this problem, the enzyme catalase is frequently used to rapidly catalyse the decomposition of hydrogen peroxide into harmless oxygen and water.(Wikipedia-the free online dictionary) There are certain factors that influence the activity of catalase: Substrate Concentration Temperature pH Salt Concentration Presence of Inhibitors Presence of Activators Hence even if the same experiment is performed several times different results may lead to different results. The student feels that the more the concentration of the liver the more the enzyme that would result since more amount of oxygen would react with the hydrogen peroxide molecules. For accomplishing this, the student has taken five test tubes with the first test tube having twice the suspension as that of the fifth tube expecting that there would be twice the amount of oxygen given off. This seems that the student wants to prove that the amount of oxygen that would be evolved would be directly proportional to the amount of the liver suspension take. Since it cannot be decided in a single experiment the student repeats it three times to observe whether the desired changes have taken place in each experiment or not. The independent variable to be considered here would be the amount of liver suspension and distilled water and the dependent variable would be the amount of oxygen evolved. This experiment deals with quantitative analysis. The overall experiment can be summed up by the following table (Note: Exp indicates experiment) It can be observed that there is a significant variation in the amount of oxygen evolved in the three experiments. The variation can be clearly understood observing the graph below It can be inferred from the graph that there is a gradual decline in the amount of oxygen evolved considering the concentrations of the enzyme. (The x-axis represents experiment and the y-axis represents the amount of oxygen evolved). It is only in the second experiment that the discrepancy arises. It is highly probable that there might have been a replacement of the suspension. It can be clearly understood that there is a direct relationship between the amount of suspension and the amount of oxygen evolved. The experiment is in fact a relatively simple one and can be performed easily if the conditions are ideal. The student has done it appropriately and has a good analytic skill. The prediction is purely based on understanding as it involves mainly quantitative analysis rather than the chemical reaction. The student has opted the right materials for accomplishing this experiment. The only requirement would be to do the experiment under perfect conditions and conduct the experiment singly so as not to confuse with other experiments. The following experiment would boost the above observation Hypothesis: Iftime is increased, then more hydrogen peroxide molecules will be split into water and oxygen. Materials: The materials used in this lab were pencils, scissors, envelope, 100 paper hydrogen peroxide molecules, and a watch with a second hand so that a person would be able to keep time for the person tearing the strips. Methods: Take a paper template and cut out 100 hydrogen peroxide molecules. Place the cut out pieces into an envelope. Then have a person act as a catalase and take one piece of the paper molecules out of the envelope at a time and rip it in two and place the pieces back into the envelope. Have a person hold the envelope person, while another student keeps track of the "tearing" time intervals (10, 20, 30 ,60, and 60 seconds). Count how many molecules are ripped at the end of each time interval and record this number in your data table. When all time intervals and counts are completed, use the formula below to figure the reaction rate for catalase. This data is recorded into the data table. M2 - M1/ T2 - T1=rate Bibliography: "Catalase FAQ", "Catalase:H2O2:H2O2Oxidoreductase", "Catalase", Read More