Effect of Amylase on Starch

Question: Write a report about the Effect of Amylase on Starch? Answer: The experiment was performed to determine the activity of salivary amylase, where the enzyme converts the starch to maltose. The enzyme hydrolyzes the-(1-4) glycosidic linkage of the starch polymers (Amira et al., 2012) into maltose and dextrin. The enzymatic action is influenced by pH and temperature (Amira et al., 2012). The amylases isolated from diverse sources (including plants, animals, and microbes) play a vital role in carbohydrate metabolism. In addition, due to associated low cost, the enzyme is being widely used in industrial production for food processing and fermentation etc. However the action of the enzyme varies from source to source. Hence the efficacy of the enzyme should be determined. The effect of amylase can be determined using iodine as an indicator. In brief the starch is treated with known concentration of amylase under identical conditions. The starch gets hydrolyzed proportionally to that of action of amylase. The starch show blue colour in presence of iodi ne solution and disappears with the degradation (conversion to smaller units) of starch. Hence the method, iodine-starch combination is used for the quantitative assessment (Xiao, et al., 2006). Amylase also shows a partial degradation of starch to amyloamylose and erythroamylose (Freeman Hopkins, 1936). As soon as the conversion is in progress the blue colour gets transformed to clear zone due to hydrolysis of starch to maltose. The results of zone of clearance obtained from the experiment are shown in Table-1 and Fig-1. Table-1: Effect of Amylase on digestion of starch based on zone of clearance Amylase conc (%) Zone of clearance/m2 0 0 0.5 40 1 80 1.5 136 2 96 2.5 128 The results suggesting that there exists haphazard pattern of results. The experimental values are not on straight-line for 2 and 2.5% amylase solutions. The zone of clearance is marginally linear to that of concentrations of amylase solution standalone (r=0.88); whereas the elimination of terminal points yielded a straight line (r=1). The correlation coefficient (r) is used as an indicator to express the linearity. The results indicate that the zone of clearance values resulted for the concentrations, 2 % and 2.5 are not in linear. Therefore these two points could be considered as the anomalies among the values. Precautions to avoid the errors Specific volumes of the samples should be pipetted accurately and trasnfrred to the glas tubes. The experiemntal considitons should be identical to all the samples. Ideally the samples should be exposed to a temperature of 37o C. In the current case, there were few errors that include improper pippeting, droping temperare from 36o C to 29o C and spillage of the samples. These are the probable reasosn for showing descreency of the results. Therefore the experiemnts showed haphzardous results. The experiemtnal errors can be minimized by care ful experimentation. The experiemnt looks to be sensitive to changes in the temperature. In addtion the method is sesnitive to changes in pH. Therefore the method further can be improved by maintaining a cosntant pH utilizing buffers and temperature for all the experiemnts. Else an advanced method based on electrophoresis (Martinez et al., 2000) may be used to yield consistent and reproducible results. References FREEMAN GG Hopkins RH (1936) The mechanism of degradation of starch by amylases: Kinetics of action of - and -amylases on starch, its components and partial degradation products. Biochemical J 30(3) p. 446-450 MARTINEZ TF., ALARCON FJ., DIAZ-LOPEZ M MOYANO FJ (2000) Improved detection of amylase activity by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with copolymerized starch. Electrophoresis. 21(14) p. 2940-3. XIAO, Z., STORMS, R TSANG, A. (2006) A quantitative starch-iodine method for measuring alpha-amylase and glucoamylase activities. Anal Biochem. 351(1) p. 146-8. AMIRA E-F., MOHAMMED AD., AHMED E-S NOHA O (2012) Starch and microbial -Amylases: from concepts to biotechnological applications, carbohydrates-comprehensive studies on glycobiology and glycotechnology, Retrieved from https://www.intechopen.com/books/carbohydrates-comprehensive-studies-on-glycobiology-and-glycotechnology/starch-and-microbial-amylases-from-concepts-to-biotechnological-applications