MISEP Chemistry 512 – Jacobs
Enzyme Catalyst Lab - Formal Report – August 8, 2007
This investigation examined what would happen to the rate of an enzyme-catalyzed reaction if the concentration of substrate changed. We hypothesized that if the concentration increased, then the reaction rate would also increase. To test our question, we varied a combination of substrate and buffer, totaling 6mL, with a constant amount of 2 drops of catalyst. The enzyme catalyst, peroxidase, increased the rate of the reaction. The results of our experiment can be found by comparing the reaction rates for each trial. These rates are actually the slopes of the lines that were graphed during each reaction. The trend of data showed that the enzyme-catalyzed reaction rates gradually decreased as the amount of substrate decreased.
MATERIALS AND METHODS
2 - 10 mL Graduated cylinders
5 to 10 medium sized test tubes
10 drops of cold Chicken liver (Enzyme Catalyst (Peroxidase)) 25 mL of buffer (H2O)
25 mL of substrate (H2O2)
Changing Concentration Methods:
Set-up LabPro equipment.
Place the chicken liver enzyme into a cold bath to maintain a cold temperature. In separate graduated cylinders, measure out 2ml of substrate and 4ml of buffer and pour both into a test tube. Add 2 drops of catalyst. Cap immediately with LabPro stopper, and start the computer measurement program. Stop recording once the stopper pops off. Using the software, find the slope of the line, which will represent the reaction rate. Print the graph for your records. Repeat steps 3 and 4, increasing the substrate by 1 mL and decreasing the buffer by 1 mL, keeping the total volume at 6ml. Do this until you reach 6mL of substrate and 0mL of buffer. (See data table) Compare reaction rates using the different slopes from the varying concentrations. RESULTS