1. Investigating Catalase
IGCSE Biology

2. Aim
To determine which type of tissue contains the highest concentration of catalase

3. Background
Catalase is an enzyme found in almost every type of living tissue
Catalase catalyses the following reaction:
Hydrogen peroxide water + oxygen
catalase
Try to find out:
What is the optimum temperature for catalase?
What is the optimum pH for catalase?
What is the chemical equation for this reaction?

4. Hypothesis You will be setting up the experiment as follows:
Liver a
potato
Boiled liver
apple
Liver b
growing splint
5ml of 3% hydrogen peroxide solution and 2ml of 5% detergent solution (except test tube E) A B C D E
What do you think will happen in each test tube? And why?
(you don´t need to draw the diagram – a few sentences is all that is necessary here)

5. Variables What is the independent variable? -what are you changing?
What is the dependant variable?
-what are you measuring?
What are the controlled variables?
-what are you keeping the same?

6. Materials 5 test tubes and a test tube rack 2 pieces of liver
1 piece of boiled liver
1 piece of potato
1 piece of apple
3% hydrogen peroxide solution
5% detergent solution
10ml measuring cylinder
Ruler
Bunsen burner
Splint
stopwatch

7. Diagram Liver a potato Boiled liver apple Liver b glowing splint
5ml of 3% hydrogen peroxide solution and 2ml of 5% detergent solution
(NO DETERGENT IN TEST TUBE E!!!) A B C D E E
Liver b

8. Method Liver a potato Boiled liver apple Liver b glowing splint
5ml of 3% hydrogen peroxide solution and 2ml of 5% detergent solution
(NO DETERGENT IN TEST TUBE E!!!) A B C D E
Set up the experiment as shown in the diagram
Add all the pieces of living tissue at the same time and leave for 3 min
Measure the height of the foam in test tubes A-D and record in a table
Take the test tube marked liver B and insert a glowing splint (if oxygen is present then the splint will light)

9. Results How will you collect your raw data?
-make sure you have table drawn with sensible headings and units
How will you present your data?
-what kind of graph would be appropriate?

10. Conclusion Do you support or reject your hypothesis?
Quote data from your graph to prove this!!
If you had to do this experiment again how could you improve it?