LAB 2: Enzyme Catalysis
I.
TITLE AND OBJECTIVES:
Discuss the four parts of the lab:
a. Observing Catalysis Behavior (catalase, heating, & liver).
b. Establishing a Base Line
c. Determining Rate of Reaction without an enzyme
d. Determining Rate of an Enyzmatic Reaction when the Substrate is exposed to
Catalase at Different intervals.
e. State your prediction for Part C & D
f. Briefly State your Results
II.
MATERIALS AND METHODS:
In four paragraphs summarize the procedure for each of the four parts of the lab.
a. Observing Catalysis Behavior (catalase, heating, & liver).
b. Establishing a Base Line
c. Determining Rate of Reaction without an enzyme
d. Determining Rate of an Enyzmatic Reaction when the Substrate is exposed to
Catalase at Different intervals.
III.
***RESULTS/DATA/OBSERVATIONS:
This should be divided into four clear sections with Headings
A. Title of this Section: TEST OF CATALASE ACTIVITY
One sentence summary of this part of the lab. Followed by data table below.
TABLE 1: Test of Catalase Activity Under Various Conditions
Test
H2O2 WITH CATALASE
Observations
H2O2 WITH BOILED CATALASE
H2O2 WITH LIVER
B. Title of this Section: ESTABLISHING A BASE LINE
One sentence summary of this part of the lab. Followed by data table below.
TABLE 2: Base Line Calculations
Data
Initial Reading of Burette
Recording (mL)
Final Reading of Burette
Base Line
(Final – Initial)
C. Title of this section: UNCATALYZED RATE OF H2O2 DECOMPOSITION
One sentence summary of this part of the lab. Followed by data table below.
TABLE 3: Uncatalyzed H2O2 Decomposition
Data
Initial Reading of Burette
Recording (mL)
Final Reading of Burette
Amount of KMnO4 titrant
Amount of H2O2 spontaneously decomposed
(Base Line from Table 2 – KMnO4)
% of H2O2 which spontaneously decomposed in
24 hours
(ml baseline – ml 5 or 6 days)/ ml baseline x
100
____________%
D. Title of this section: TIME COURSE DETERMINATION
One sentence summary of this part of the lab. Followed by data table & Graph
TABLE 4: TIME COURSE DETERMINATION OF CATALASE
KMNO4
10
30
60
90
sec
sec
sec.
sec
BASE LINE
(from table 2)
Initial Reading
120
sec.
180
sec.
Final Reading
Amount of
KMnO4
consumed
(Final – Initial)
Amount of H2O2
(Baseline –
Amount of
KMnO4)
TABLE 5 SAMPLE DATA TIME COURSE DETERMINATION OF CATALASE
360
sec.
KMNO4
10
sec
30
sec
BASE LINE
(from table 2)
Initial Reading
3.4
3.4
60
sec.
3.4
120
sec.
3.4
180
sec.
3.4
360
sec.
3.4
8.6
10.2
11.2
11.5
11.6
11.6
Final Reading
6.1
8.6
10.2
11.2
11.5
11.6
Amount of
KMnO4
consumed
(Final – Initial)
Amount of H2O2
(Baseline –
Amount of
KMnO4)
2.5
1.6
1.0
.3
.1
1 drop
.9
1.8
2.4
3.1
3.3
3.4
One sentence Summary of Graph
Graph of the Data:
X Axis: Time in seconds
Y Axis: Amount of H2O2 used
Title of Graph: Amount of H2O2 Decomposed by Catalase for Different Time Intervals
IV.
***ANSWERS TO QUESTIONS: In this section, put answers to the questions in your
lab book.
Write Question & Answer out
1. From this formula Change y/Change X determine the initial rate of the reaction and the rates
between each of the time points. Record the rates in the table below.
Rate of Reaction
Initial
10 to 30
30 to 60
60 to 90 90 to 120
120 to
180 to
0 to 10
180
360
RATES
2. When is the rate the highest? Explain why.
3. When is the rate the lowest? For what reason is the rate low?
4. Explain the inhibiting effect of sulfuric acid on the function of catalase. Relate this to enzyme
structure and chemistry.
5. Predict the effect that lowering the temperature would have on the rate of enzymatic activity.
Explain your prediction.
6. Design a Controlled Experiment to Test the Effect of Varying pH, temperature, or enzyme
concentration.
V.
***DISCUSSION:
First Paragraph: Restate objective of each part of lab and summarize results for each section.
Second Paragraph; Discuss Data from Table 1. Use words used in your data table. Was your
hypothesis correct? Yes or no and why?
Third Paragraph: Discuss Data from Table 3. How much H2O2 spontaneously broke down. Did
this meet your prediction? Why or why not?
Fourth Paragraph: Discuss Data from Table 4 & your graph & Rate of Reaction. Did the data
make sense? Explain your numbers. If there were errors can you explain what happened? What
direction was the graph? Did this make sense? Was your object met?
Fifth Paragraph: Discuss Errors in lab. What went wrong & how can it be improved?
Sixth Paragraph: Extend this lab. What implications does studying enzymes have on your life?
Can you think of another experiment that could be done to benefit society.