Prepare a laboratory report on investigating the effect of PH on the rate of catalase activity.
Materials
a. Enzyme source
b. Thermometer
c. Hydrogen peroxide (20%)
d. Knife
e. Range of buffer solution -acidic, neutral and alkaline
f. Chopping board
g. PH paper
h. Electronic balance
I. Washing up liquid
j. Weigh boats
k. Large beaker of water at 25°c
l. Disposable gloves
m. Graduated cylinder (100cm³)
n. Labels
o. Strange
p. Timer
q. Boiling tubes
r. Dropper
s. Test tube rack
t. Pipette
u. Stopper
v. Distilled water
Procedure
1. Set up the experimental materials and equipment as shown in the diagram below.
2. Label the boiling tubes as acidic, neutral, and alkaline.
3. Prepare the buffer solutions by following the instructions provided with each buffer solution.
4. Use the thermometer to measure the temperature of the water in the large beaker. Adjust the temperature to 25°C if necessary.
5. Put on disposable gloves and carefully chop the enzyme source into small pieces. Weigh 3g of the enzyme source using the electronic balance and transfer it to a weigh boat.
6. Pour 50cm³ of hydrogen peroxide (20%) into a graduated cylinder.
7. Use the dropper to add 1 drop of washing up liquid to the hydrogen peroxide. Mix gently with the dropper.
8. In the test tube labeled "acidic," add 10cm³ of the acidic buffer solution.
9. In the test tube labeled "neutral," add 10cm³ of the neutral buffer solution.
10. In the test tube labeled "alkaline," add 10cm³ of the alkaline buffer solution.
11. Using the pipette, add 10cm³ of the enzyme source to each test tube. Start the timer immediately after adding the enzyme.
12. Observe the reaction in each test tube and record the time it takes for the reaction to stop.
13. Repeat steps 8-12 for each pH level at least 3 times to ensure accuracy.
14. Clean all equipment thoroughly with distilled water after each run to prevent cross-contamination between pH levels.
Results
Record the time taken for the reaction to stop in each test tube at each pH level. Calculate the average time for each pH level.
Analysis
Plot a graph of pH level (x-axis) vs. rate of catalase activity (y-axis) using the average times from the results. Analyze the graph to determine how pH affects the rate of catalase activity.
Conclusion
Summarize the findings from the analysis and draw a conclusion regarding the effect of pH on the rate of catalase activity. Discuss any limitations of the experiment and suggest areas for further research.