SBI 4U
Petrany
Investigating Factors That Affect Enzyme Function
Adapted from Nelson Biology 12 (2012)
Enzymes are catalysts that increase the rate of specific reactions in living
organisms. In this investigation, you will plan and conduct an experiment to test how
different environmental conditions affect enzyme activity. The compound hydrogen
peroxide is a by-product of metabolic reactions in most living organisms. However,
hydrogen peroxide is damaging to molecules inside cells. As a result, nearly all
organisms produce one of a group of enzymes called peroxidases, which break down
hydrogen peroxide as it is formed. Potatoes are a source of a peroxidase specifically
known as catalase. Catalase facilitates the breakdown of hydrogen peroxide into water
and gaseous oxygen. This reaction can be detected by observing the oxygen bubbles
generated.
The Assignment
Using the information given in the above paragraph, the resources provided in
class by your teacher and your own research, you must create and implement an
investigation into the factors that affect enzyme function. Specifically, you will be testing
the effects of specific factors on the rate of activity of the enzyme catalase on the
substrate hydrogen peroxide (H2O2).
For this assignment you must provide:
1. A title page
2. An introduction to the investigation
5. A list of materials used
6. Procedures Used to Conduct the Investigation
7. Results
8. A discussion of your results (see the discussion questions on page 2 of this handout
for guidance).
9. Conclusions
Please refer to the 4U General Lab Outline and the Purdue University APA Style Guide
(link on class website) for proper formatting and content.
SBI 4U
Petrany
Guiding Discussion Questions
1. Did your results support your prediction and hypothesis (should be restating
prediction and hypothesis)? Explain. (T/I; C)
2. What evidence (results compared to prior knowledge) do you have to explain why
your prediction and hypothesis were either supported or not supported? (i.e. possible
sources of error? Problems or things you could change about your experimental
design?) (T/I; C)
3. Were you able to control all possible variables while manipulating only one in this
experiment? (i.e. are temperature and pH the only factors that could affect enzyme
function?) (T/I; C)
4. What possible variables or conditions could you manipulate to further study the
function of this enzyme? (A; C)
5. The catalase we used to breakdown H2O2 in this experiment was present in the
potato. What other foods is catalase found in? Can catalase work on other substrates?
(T/I; A; C)
Mark Breakdown
Title Page – 5 marks
Introduction – general knowledge; background research; question, prediction,
hypothesis – 10 marks
Experimental Procedure – 10 marks
Discussion Questions:
#1 – 4 marks
#2 – 5 marks
#3 – 4 marks
#4 – 2 marks
#5 – 4 marks
Conslusion – 6 marks
Total = ______/50 marks
This assignment is due Wednesday, March 6 – Sunday, March 10 at 11:59 pm.
You may hand in your lab using ONE of the following methods:
1. A hard copy delivered to your teacher in class.
2. As an attachment through e-mail – tracy_petrany@kprdsb.ca Please remember
to include an appropriate and specific subject for the e-mail i.e. Factors That
Affect Enzyme Function Lab
3. A “DROP BOX” on D2L. The drop box for this assignment can be found using
the following pathway: Assessments --- Drop Box --- Factors That Affect Enzyme
Function Lab (Under Unit 1).