Laboratory Studies on Bio-Enzyme Stabilized Lateritic Soil - pmgsy
Enzyme Salad Laboratory
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Transcript of Enzyme Salad Laboratory
ENZYME KINETICS
• 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.
BACKGROUND
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
Enzyme Salad Lab
Background Information Enzymes
Effect of temperature
Gelatin
Pineapple
Pre-Lab Discussion
Rationale Time Objectives Materials Procedure
TUBE CONTENTS RESULTS
1. Gelatin and Fresh Pineapple
2. Gelatin and Canned Pineapple
3. Gelatin and Frozen Pineapple
4. Gelatin
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)
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 of pineapple. Clean up is easier if they cut the fruit on paper plates.
c. Canned Pineapple: Use the chunky style.
Application of the Enzyme Kinetics
• •All of the three activities comes with quiz questions to be completed after the
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.
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"
In a Discovery Lesson…
the lesson proceeds through a hierarchy of stages which may be associated with Bruner's levels of thought
• the teacher decides the concept, process, law or piece of scientific knowledge which is to be "discovered“
3 Stages of the Discovery Approach
• Enactive Level
• Ikonic Level
• Symbolic Level
J. BRUNER
Enzyme Kinetics for 3 School Levels
Level Achievement of Learning Goals Skill Sets
PrimaryMake a distinction between the controls and
variables of the experiment in order to conclude the presence of enzymes
Scientific ObservationRecord KeepingFollowing Instructions
HighSchool
Recognition of the Enzyme-Substrate ComplexAnalysis of Temperature Sensitivity of the
EnzymeRecognition of the effect of denaturation on
enzyme activity
Hypothesis DevelopmentScientific 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 AnalysisReaction MechanismsTeamwork
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/enzyme_activity/ teachers_guide_evaluation.html
Scott, S. Mixed Plate Biology. (2004). www.woodrow.org. Retrieved on December 4, 2006. http://woodrow.org/teachers/aelm