Effects of Low pH on Enzyme Amylase - Research Paper Example

Outline of the effect of low pH on the activity of enzyme amylase on starch Definition of the enzyme amylase The background information about the enzyme and its role. Effects on the enzyme activity when subjected to extreme conditions of low and high pH. Hypothesis of the experiment 2. Materials and methods A simple experiment is showing effects of the enzyme when exposed to low pH values. The small sample size with equal treatments at very minimal time intervals. Control experiment without the enzyme and the changes it has with starch. 3. Results Color changes before and after reaction of the mixture enzyme amylase after being subjected to acidic fluid and starch with iodine solution in tabulated form. 4. Discussion Analyzing results and comparing with other results and literature before. 5. Conclusion Concluding the entire experiment and justifying the hypothesis. Effects of low pH on enzyme amylase Introduction Enzyme refers to the protein molecule serving as a biological catalyst by increasing the reaction rate but without changing its structure at the end of the reaction. The enzymes catalyze metabolic reactions within the living things by working to bind a substrate that is the reactant. This is mainly at their active sites thereby forming an enzyme- substrate complex and, the substrate converted to the product (Bernfeld 151). After the substrate has been converted, the product is released leaving the reaction in the same way it started. Thus, an enzyme can be used for many times in reaction purposes. The enzyme catalyzes specific reactions, for example; enzyme amylase catalyzes starch conversion to maltose. When an enzyme is not at the optimum level, it functions more slowly or at times does not even work at all. Enzyme denaturation takes place when the reaction is subjected to extreme high or low pH. This results in the enzyme losing secondary, tertiary and quaternary structures thereby becoming a chain of amino acids joined by peptide bonds (Van Der Maarel 137). In the scientific experiment below, the enzyme amylase was subjected on different pH concentrations of the acid HCl and the effect tested on its activity with starch. This is because the enzyme main function is to convert starch into maltose. The reagent iodine was used to test the presence or absence of starch after the enzyme was subjected in the different concentrations of the acid HCl. The hypothesis of the experiment is that during extreme conditions, in low pH concentrations that are very acidic, enzyme amylase will be rendered functionless in its activity on starch as a result of the denaturation effect. Materials and methods Materials Nine test tubes, four different solutions having different pH values of 2, 4, 5 and 6 in terms of concentration were used in the experiment. Moreover, water bath at a given temperature was used, 1% starch solution and amylase buffer solution. Lastly, iodine solution and spot place was used in the experiment. Methodology Four test tubes with pH solutions of 2, 4, 5 and 6 of hydrochloric acid each were arranged and labeled. 4ml of appropriate buffer solution was added to the different tubes corresponding to the pH concentration of HCl, allowed to react before adding 4ml of the solution of amylase to three tubes. The remaining tube without the amylase content acted as a control experiment to determine the presence of starch. Additional four test tubes were then arranged, and 4ml of 1% starch solution added. The 8 test tubes were then placed in a water bath for 370C for 5 minutes. Starch content was then poured into the test tubes containing amylase-buffer, and the one without amylase, mixed and returned to the water bath. Four drops of the reaction mixture were then transferred to the spot plate, and iodine solution added. Observations were then recorded and level of enzyme activity determined for each of the mixtures. A graph showing relationship between the pH and enzyme activity was plotted to analyze the results. Results Table1 shows color change in the different test tubes after addition of starch content Test tube pH value of the acid HCl concentration Color before adding iodine Color after adding iodine Test tube 1 (mixture of starch and amylase) 6 Colorless Color of mixture retained Test tube 2 (mixture of starch and amylase) 2 Colorless Color changed to blue-black Test tube 3 (only starch content) 4 Colorless Color changed to blue-black Test tube 4 (mixture of starch and amylase) 5 Colorless Color of mixture retained Discussion The addition of HCl of different concentrations to enzyme amylase changes its effect due to denaturation. Iodine solution is used to test the presence of starch. The enzyme amylase converts starch to maltose (Fuwa 599). The control test tube tested negative for the activity of the enzyme because the enzyme was lacking. The color changed to blue-black because iodine reacted with the starch present. The solutions of HCl of pH 5 and 6 retained the color of the mixture after the addition of starch content showing the absence of starch. The reason is that the starch content in the solutions has been converted to maltose and, therefore, the activity of the enzyme was positive. The concentration of the acid shown by the low pH did not denature the enzyme and thus, the enzyme could still act on the starch. In test tube two that had a pH of 2 of HCl acid, color changed to blue-black. This is because at the pH f 2, the condition is extremely acidic, and, therefore, the enzyme amylase gets denatured. Iodine, therefore, reacts with the remaining starch content thus color change. The activity of the enzyme at the acidic pH of 2 was lower and increased at the pH of 5 of the acid, representing the optimum pH value. Above the pH of 5, the activity lowered again at the pH of 6. Therefore, a graph of reaction velocity against pH of HCl acid on enzyme amylase is as shown in the graph below. A graph showing relationship between reaction of enzyme amylase and the pH in the activity (Van Der Maarel 145) Conclusion Each and every enzyme has optimum pH of a given acid in their level of activity. When the value is below or above the optimum pH, then the activity of the enzyme gets lowered. As exemplified by Bernfeld 151, optimum pH of any enzyme will correspond to pH of the natural environment the activity is taking place. Extreme low values of acidic fluid results in complete loss of most enzyme activities. The pH change also leads to stability of enzymes and as for the activity each enzyme has an optimal region for pH stability and varies considerably in the enzymes. Thus, the hypothesis of the experiment was tested. The pH of any solution may have several effects on the activity and structure of a given enzyme. For instance, pH has an effect on ionization effect of both basic and acidic amino acids. The side chains of acidic amino acids have the carboxyl as the functional groups, and the basic amino acids have the amine groups as the functional ones. Therefore, the alteration of the ionization state of amino acids in a protein leads to the alteration of the ionic bonds determining the 3-D type of shape of a protein. As a result, protein recognition is altered, and the enzyme may become inactive in the end. The pH changes of an acid affect the protein shape and also charge properties of the substrate are making it not to bind to the active site and not to undergo catalysis effects (Fuwa 596). Work Cited Bernfeld, Peter. "[17] Amylases, α and β." Methods in Enzymology 1 (1955): 149-158. Fuwa, Hidetsugu. "A NEW METHOD FOR MICRODETERMINATION CF AMYLASE ACTIVITY BY THE USE OF AMYLOSE AS THE SUBSTRATE." The Journal of Biochemistry 41.5 (1954): 583-603. Van Der Maarel, Marc JEC, et al. "Properties and applications of starch-converting enzymes of the α-amylase family." Journal of Biotechnology 94.2 (2002): 137-155. Read More