This document discusses an enzyme kinetics lab activity for students at different school levels. The activity involves adding pineapple containing the enzyme bromelain to gelatin to observe how enzymes break down their substrates. For primary students, the goal is to distinguish controls from variables and understand enzyme presence. High school students additionally analyze temperature effects and enzyme denaturation. College students conduct detailed experiments, model reaction equations, and quantify results graphically. The activity aims to teach enzyme function through discovery learning at different cognitive levels.

1. ENZYME KINETICS

2.
BACKGROUND
• Students in introductory biology classes often have difficulty
understanding many aspects of enzymes.
•Since the physiology of organisms is based on the existence and speed of
chemical reactions, it is essential to understand basics in enzyme
activity in order to understand how life can exist.
•As students discover the importance of enzymes, they are better prepared to
apply their knowledge to real world applications.
•Study of enzymes is a difficult topic for most students because it is an
intangible topic.

3. Objectives

To allow students to learn
science through the
process of discovery

To provide a representation
of how one of life’s basic
processes occur

To motivate learners to
make their own discoveries
of knowledge

4. Enzyme Salad Lab

5. Background Information

Enzymes

Effect of temperature

Gelatin

Pineapple

6. Pre-Lab Discussion





Rationale
Time
Objectives
Materials
Procedure

7. TUBE CONTENTS
RESULTS
1. Gelatin and Fresh Pineapple
2. Gelatin and Canned Pineapple
3. Gelatin and Frozen Pineapple
4. Gelatin

8. DISCUSSION
QUESTIONS
1. Why did test tube #4 contain only gelatin?
2. What could account for the different results in the tubes?
3. How could the canning process change bromelin?
4. What other fruits contain protein-digesting enzymes?
5. Using fresh pineapple, determine the temperature at
which the enzyme denatures. (for HS and college
students)
6. Design an experiment to find a temperature at which a
meat tenderizer works the best. (for college
students)

9. NOTES
1. We usually do this lab when we are discussing digestive enzymes and
temperature dependence of enzymes. The students like the application of
biochemistry to something they eat.
2. Suggestions:
a. Preparing the gelatin: Stir two envelopes of unflavored gelatin into 800
ml of hot water. This should be enough for three classes. Store it in a warm
water bath when the students are
using it so it will pour easily.
b. Remind the students to rinse of the razor blade between types
pineapple. Clean up is easier if they cut the fruit on paper plates.
c. Canned Pineapple: Use the chunky style.
of

10. Application of the
Enzyme Kinetics
•• of the three activities comes with quiz questions to be completed after the
All
experiment. These questions will be used to evaluate the learning
experience for the class.
•The concepts explored will apply to different students at different levels. For
example, the concept of a reaction mechanism is too complex for
elementary or even some high school students to understand. Thus,
quantitative analysis of the kinetics is reserved to the college level.
• The experiment provides a big picture of the framework of the basic concepts
of enzyme kinetics: what enzymes are, how they work, and how
they can be used.

11. The
DISCOVERY APPROACH
The discovery
approach was first
popularized by Jerome
Bruner in a book The
Process of Education

The concept behind the
discovery approach is that the
motivation of pupils is to learn
science will be increased if they
experience the feelings scientists
obtain from "discovering"
scientific knowledge
The idea was supported by the
notion that pupils would learn about
the nature of science, and the
formation of scientific knowledge
through the process of "discovery"

12. In a Discovery Lesson…
• t he t eacher decides t he
concept , pr ocess, law or
piece of scient if ic knowledge
which is t o be "discover ed“

t he lesson pr oceeds t hr ough
a hier ar chy of st ages which
may be associat ed wit h
Br uner ' s levels of t hought

13. 3 Stages of the
Discovery Approach
• Enactive Level
• Ikonic Level
• Symbolic Level
J. BRUNER

14. Enzyme Kinetics for 3
School Levels
Level
Achievement of Learning Goals
Skill Sets
Primary
Make a distinction between the controls and
variables of the experiment in order to
conclude the presence of enzymes
Scientific Observation
Record Keeping
Following Instructions
High
School
Recognition of the Enzyme-Substrate Complex
Analysis of Temperature Sensitivity of the
Enzyme
Recognition of the effect of denaturation on
enzyme activity
Hypothesis Development
Scientific Inference
College
Perform a detailed experiment with quantitative
analysis
Justify modeling equations with experimental
results
Use graphical methods on MS Excel to quantify
the results
Data Analysis
Reaction Mechanisms
Teamwork

15. References
Balala, S. (2003). Activities-To-Go. www.acessexellence.org.
Retrieved on December 4, 2006.
http://accessexellence.org/AE/ATG
Collette, A. and Chiapetta, E. (1994). Science Instruction in the
Middle and Secondary Schools. New York, USA: Macmillan
Publishing Company.
Duit, R. (2002). Pineapple-Jell-O Lab. www.dev.mdk12.org.
Retrieved on December 6, 2006.
http://dev.mdk12.org/instruction/curriculum/hsa/biology/enz
yme_activity/ teachers_guide_evaluation.html
Scott, S. Mixed Plate Biology. (2004). www.woodrow.org.
Retrieved on December 4, 2006.
http://woodrow.org/teachers/aelm