INVESTIGATIVE PROJECT
NAME:
DATE: 2022/05/17
SUBJECT: Biology Unit 1
TITLE: The effect of pH on the activity of Catalase
AIM: To compare the number of bubbles produced from the decomposition of H2O2 by the
enzyme catalase at different pH conditions.
INTRODUCTION
Give information about the enzyme catalase, where it is found and how it works.
Also discuss what the information is all about
APPARARTUS AND MATERIALS
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3 Test tubes
3 potato cubes
Sulfuric acid (H2SO4)
Sodium hydroxide (NaOH)
Hydrogen peroxide (H2O2)
Distilled water
Razor blade
METHOD
1. Three (3) test tubes were labelled with the numbers: 1, 2, and 3.
2. The following was added to the appropriate test tubes:
Test Tube # 1: 3 ml of distilled water and 1 diced potato cube.
Test Tube # 2: 3 ml of sulfuric acid (H2SO4) and 1 diced potato cube.
Test Tube #3: 3 ml of sodium hydroxide (NaOH) and 1 diced potato cube.
3. After 3 minutes, the pH of each test tube was measured with a small piece of pH paper.
4. 5 ml of hydrogen peroxide (H2O2) was added and the number of bubbles produced was
observed.
5. The results were tabulated.
RESULTS
Table showing the degree of bubbling at different pH conditions.
Test Tube
1-Distilled water
2-Suphuric acid
3-Sodium hydroxide
pH
Number of
Bubbles
Explanation
DISCUSSION
Discuss the results in detail.
Explain how the ph affected the activity of the enzyme catalase (be specific to the results
of the experiment
LIMITATIONS
 The potato cubes may not have been the exact dimension and the variations in size
may have affected the amount of catalase acting on H2O2
 The activity of catalase could have been affected by the temperature of the
environment.
SOURCE OF ERRORS
 Experimenter error in counting bubbles when they were generated.
PRECAUTIONS
 Care was exercised when handling the chemicals.
REFLECTION
State what you learnt from the experiment
State how the experiment is relevant to real life
Discuss the Impact of knowledge gained from experiment
How can the experiment be changed and improved
CONCLUSION
Make a conclusion and state if the hypothesis is true or not.
Investigative Project
Skill Assessed: A/I
Criteria
Results
Complete set of results from quantities mentioned in method
Discussion
Complete set of calculations or statement of observations or
trends
Interpretations of calculated values, observations or trends
linked to data in results
Limitations and Sources of Error
Limitation stated
Source of error stated
Reflections
Relevance of experiment to real life
Impact of knowledge gained from experiment
How can experiment be changed and improved
Conclusion
Clearly stated and related to aim in PD
Total
Maximum
Marks
2
2
2
1
1
1
1
1
1
12
Marks
Awarded