Enzymes Lab Report Example | Topics and Well Written Essays - 1250 words

Enzymes - Lab Report Example Following addition of iodine to a solution of glucose, the only color observed was red or yellow (iodine color). Therefore, the faster the blue color is lost, the faster the enzyme amylase activity. The enzyme amylase can’t hydrolyze starch if it is inactivated, so the starch-iodine complex blue color will persist. The presence of glucose in the samples was tested using Benedict’s reagent. When blue solution of Benedict’s reagent is added to a glucose solution the color changes to green (at low concentrations of glucose) or reddish-orange (at higher concentrations of glucose). Starch can’t react with Benedict’s reagent, therefore the solution remains blue. The aim of the experiment was to look at how enzyme amylase activity is affected by pH, temperature and concentration of the enzyme. Introduction Enzymes are proteins in nature; they are catalysts for biological reactions. Like all catalysts, they speed up reactions by lowering the reactionâ€℠¢s activation energy without themselves being used up. Enzymes catalyze all biochemical reactions. They can be denatured in a variety of ways since they are proteins in nature, Therefore they work optimally under mild conditions. At body temperature and at a neutral pH, most of them have optimum activity. Enzymes also are known to be very specific; they act only on a specific substrate or one type of similar substrate molecules. This is because the enzyme active site is complementary to the polarity and shape of the substrate. Only one kind of substrate will â€Å"fit† into the active site. (Abu et al, 2005) Methods and Materials Preparation: Water baths of constant, low and high temperature were used in the experiment. A large water bath was set to 37 °C.For low temperature bath, a 250-mL beaker, was half filled with tap water, and some ice was added to the water to attain between 0 and 5 °C temperature. High temperature water bath was made by filling a 250-mL beaker to two-thirds full then heated to boil. The temperature of the bath was close to 100 °C. 1% starch solution was used for every experiment part. Iodine reagent for each experiment was also used. Commercial amylase solution, clean droppers and a white spot plate were also needed in the experiment. For starch testing, few drops of starch were transferred to one well of the spot plate. One iodine reagent drop was added. Iodine and Starch was reacted to form a deep blue-black complex. For glucose testing, 1% glucose solution of 3 ml was added in a test tube. 2 ml of Benedict’s solution was added and heated in a boiling water bath for 3-4 minutes. The reaction formed a red-orange solid. Experiment 1: Effect of Enzyme Concentration Five test tubes were labeled as 1-5. 4 ml of 1 % starch was placed in every first four test tubes. 4 ml of amylase solution was placed in the fifth tube. All of the tubes were placed in water bath (37 °C) for 5 minutes. 5 clean droppers were obtained the n labeled from 1 to 5.Separate dropper were used for each mixture to avoid contamination. Tube 1 was the control and it never had any enzyme. The tubes were momentarily removed from the water bath and quickly 3 drops of the warmed amylase solution was added to tube 2, to tube 3, 6 drops of amylase was added and in tube 4, 10 drops of amylase was added. The tubes were mixed quickly by shaking gently then later put immediately back into 37 °C water bath. The time at which the enzyme was added was