Name: _______________________________
Date: ___________
AP Biology Lab 2: Enzyme Catalysis
Report
WHAT
Topic: enzymes, enzymatic action
Vocabulary: activation energy, active site, allosteric site, catalyst, coenzyme, cofactor,
denatured, enzyme, product, substrate
Expected results:
• The titrated amounts will decrease over time
AP Lab 2: Enzyme Catalysis Sample Results
2/22/10 7:
AP Lab 2: Enzyme Catalysis Sample Results
2/22/10 7:
Actual results:
• No consistent results obtained
Lab 2
2
Lab
(alternative results)
Enzyme Catalysis
Catalysis
Enzyme
Results: Table 1: Test of Catalysis Activity
Results: Table 1: Test of Catalysis Activity
Part I
Part I
Experiment
Experiment
Hydrogen Peroxide
Hydrogen Peroxide
Catalase in potato
Catalase in potato
Hydrogen Peroxide
Hydrogen Peroxide
Catalase in potato
Catalase in potato
+ Fresh
+ Fresh
+ Boiled
+ Boiled
Hydrogen Peroxide + sulfuric acid
Hydrogen Peroxide + sulfuric acid
+ potato
potato
+
Observations
Observations
Bubbling in solution with the release of
Bubbling in solution with the release of
oxygen.
oxygen.
No reaction occurred.
No reaction occurred.
No reaction occurred
No reaction occurred
Part II
II Reaction
Reaction Rate
Rate with
with Changing
Changing Enzyme
Enzyme Concentrations
Concentrations
Part
Enzyme Concentration
Concentration
%of reaction (s)
Enzyme concentration
(%) Speed%
Enzyme
20
20
20
15.8
40
40
12.1
6040
60
Speed of
of Reaction
Reaction in
in seconds
seconds
Speed
15.8
15.8
8060
80
100
100
80
9.9
12.1
12.1
9.9
9.9
5.8
5.8
5.8
41.
41.
100
4.1
Name: _______________________________
Date: ___________
HOW
Ideal procedure: Set up controlled enzyme catalysis experiment.
• Keep most conditions constant (same containers, same amounts of hydrogen peroxide, same
titrate solution)
• Vary some conditions -- the independent variables (different reaction times)
• Measure one variable over time -- the dependent variable (titrated amounts)
Actual procedure: (alternative)
• Keep most conditions constant (same containers, same amounts of hydrogen peroxide, same
titrate solution)
• Vary some conditions -- the independent variables (different enzyme concentrations)
• Measure one variable over time -- the dependent variable (reaction rate)
WHY
Explanation of alternative results:
• Enzymes like catalase are chemical catalysts; under the right conditions, each enzyme can
catalyze multiple reactions
• The more enzymes present, the faster the reaction rate
Explanation of alternative process:
• All of the substrate molecules present in solution will be converted into product molecules
when enzymes are present -- the time it takes for that to happen is measurable
CONCLUSIONS
Big ideas:
Connections: