Enzyme Amylase - Lab Report Example

An enzyme is a protein-based catalyst that raises the reaction rate of a reaction by lowering the activation energy needed for that reaction. It is not used up in the process. It is hypothesized that the enzyme activity changes when various parameters such as temperature, pH and the concentration of the enzyme are changed. Materials: The materials used were: 400 mL beakers, thermometers, hot plate, ice, 1% starch solution, 2 grams of soluble starch, iodine in dropper bottles, buffer solutions with pH levels of 4, 7 and 10, well (spot) plate labeled 1, 2, 3 and 4, saliva (amylase) solution, test tube rack, test tubes, droppers, a 10 mL graduated cylinder and water squirters.

Method: a) Reference color A few drops of 1% starch solution were placed on a spot plate. One drop of iodine was added to the spot. The color that formed was taken to be the reference color. b) Effect of concentration. A 400 mL beaker was half-filled with water and then warmed to 37?C. The temperature was kept constant at 37?C. Saliva was collected in a disposable tube. 4 mL of 1% starch solution was placed in a test tube. This tube was placed in the water bath for five minutes. In spot plate 1, no spit was added, in plate 2, one drop of saliva was added, in plate 3, three drops of saliva were added and in plate 4, five drops of saliva were added.

Eight drops of 1% starch solution were then added to each well plate. . The plate was then rinsed with water and the test repeated twice after intervals of 5 and 10 minutes. After each test, the observations made were recorded. A graph of the enzyme activity against the amount of amylase at 10 minutes was then plotted. c) Effect of temperature. 1 mL of 1% starch solution was placed in two test tubes. One of these tubes was placed in a water bath with boiling water and the other in an ice bath.

1 mL of the 1% starch solution used in method a) above was placed in a test tube. This test tube was then placed in a water bath with a temperature of 37?C. The three tubes were left in the baths for 10 minutes. The temperatures of the baths were then recorded. Two drops of saliva were placed in 3 well plates and then one drop of iodine added to each plate. Four drops of the 1% starch solution in the test tube contained in the ice bath were added to one spot, another four drops of the starch solution in the test tube contained in the water bath at 37?

C were added to the second spot, and finally four drops of the starch solution in the test tube contained in the water bath with boiling water were added to the third spot. The observations made were recorded and a graph of enzyme activity against temperature plotted. d) Effect of pH 2 mL of each of the three buffer solutions (with pH levels of 4, 7 and 10) was placed in separate test tubes. 2 mL of 1% starch solution was then placed in three other test tubes. All the test tubes were then placed in a water bath with a temperature of 37?

C for five minutes. The three 1% starch solutions were then poured into three buffer solutions and then mixed thoroughly. The test tubes with the mixtures were then returned to the water bath. Three drops of spit were placed in three spot plates. Using clean droppers,