Classic Articles as PBL Problems in Introductory Courses

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Classic Articles as PBL Problems in Introductory
Courses

• Hal White
• Dept of Chemistry and Biochemistry
• University of Delaware
• PBL2000 31 October 2000

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Session Outline

• The Case for Classic Articles
• Example of an Article-Based Course
• Experience a Classic Article Problem
• Designing a Course Around Classic Articles
• Student Response
• Questions and Answers

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Characteristics of Good PBL Problems

• Engage interest
• Require decision and judgement
• Need full group participation
• Open-ended or controversial
• Connected to prior knowledge
• Incorporate content objectives

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Classic Articles as PBL ProblemsAdvantages

• Authentic (not contrived)
• Complex
• Relevant to the Discipline
• Introduce Important Historical Figures
• Encourage use of Library

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Introduction to BiochemistryEvolution of the
Course

• 1970's Course for non-science majors based on
  Herman Epsteins model.
• 1989 Modified course initiated as part of a new
  B.S. Biochemistry curriculum.
• 1993 Problem-Based Learning format introduced.
• 1996 Undergraduate Tutor-Facilitators used for
  the first time.

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Introduction to BiochemistryAn Article-Based
PBL Course

• 3 Credits, No Laboratory, 800 AM MWF
• Theme - Hemoglobin and Sickle Cell Anemia
• First Biochemistry Course for Sophomore
  Biochemistry Majors
• Required for the Major
• Taught in a PBL Classroom
• Enrollment 20 - 35
• Uses Juniors and Seniors as Group Facilitators

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Introduction to BiochemistryCourse Description

• Heterogeneous groups of 4 discuss and work to
  understand about ten classic articles.
• Articles presented in historical context, show
  the development of scientific understanding of
  protein structure and genetic disease.
• Assignments and examinations emphasize conceptual
  understanding.
• Instructor monitors progress, supervises tutors,
  presents demonstrations, and leads whole class
  discussions to summarize each article.

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Introduction to BiochemistryInstructional Goals
For Students

• 1. Become intellectually independent learners
• 2. Recognize and confront areas of personal
  ignorance
• 3. Review and apply chemical principles in a
  biochemical context
• 4. Improve problem-solving skills
• 5. Create, understand, and value abstract
  biochemical models
• 6. See biochemistry in relevant historical and
  societal contexts
• 7. Discover and use the resources of the library
  and the Internet
• 8. Gain confidence in reading and understanding
  scientific articles
• 9. Experience the powers (and pitfalls) of
  collaborative work
• 10. Appreciate importance of clear oral and
  written communication
• 11. Learn to organize logical arguments based on
  evidence

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• CHEM 342
• INTRODUCTION TO BIOCHEMISTRY
• COURSE READER
• Spring Semester 2000
• CONTENTS
• About this Reader
• Course Syllabus
• Tentative Schedule
• Learning Issue Matrix for the Course
• Undergraduate Research Opportunities
• List of Articles in this Reader
• Articles in this Reader, () with Background
  Material
• Stokes (1864)
• Zinoffsky (1886)
• Bohr, Hasselbalch, and Krogh (1904)
• Peters (1912)
• Douglas, Haldane, and Haldane (1912)
• Conant (1923)

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Forming Heterogeneous Groups Without Information

• Had a college Chemistry course, add 100
  (100)
• Had a college Biology course, add 50
  -
• Avoided science in college, add 5 -
• If you are Male, add 100 (100)
• If you are Female, add 200 -
• Sum digits of your Social Security Number
  (43)
• Sum digits of your office Phone Number
  (31)
• GRAND TOTAL (Your Number) (274)
• When you have calculated Your Number,
  line up in numerical order.
• Source of method, Steve Richardson, Winona State

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Instructions for Stokes (1864)

• As a group, consider each numbered section of the
  Stokes (1864) article in order
• Begin each section by having one member of your
  group read it aloud.
• Spend as much time on each section as you want
  but dont go beyond Section 8.
• Assignment Make a list of the concepts and facts
  that students would need to know (or review) in
  order to understand this article.

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Constructing Meaning from Stokes (1864)

• What was done? Read Section 11 of the Stokes
  article. In the left-hand column of the work
  sheet, transform Stokes description into a
  multi-step protocol suitable for an undergraduate
  chemistry laboratory experiment.
• What was seen? In the middle column, describe
  what observations students would make.
• What happened chemically? In the last column,
  explain briefly in words the chemical basis for
  the observations.
• How do we represent it? On the back of the work
  sheet, construct a diagram (model) that
  represents the chemistry.

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Reducing Agents
Oxidized Products
H2CO3
O2
H2O
O2
Irreversible
Reversible
Scarlet Cruorine
Purple Cruorine
Conceptual model for the reactions of cruorine
described by Stokes. The color of the squares
corresponds to the spectral properties of the
compound involved.
Acid, Heat, Organic Solvents
Acid, Heat, Organic Solvents
Irreversible Decomposition
Albuminous Precipitate
Reducing Agents
O2
Brown Hematin
Red Hematin
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Introduction to Biochemistry Student Assignments

• Write an Abstract
• Construct a Concept Map
• Draw an Appropriate Illustration
• Critique from a Modern Perspective
• Find out about the Author
• Explore a Cited Reference

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Contains
BLOOD TRANSPORT OF OXYGEN
BLOOD
Red Blood Cells
CHEMISTRY
Lyse in water to release
Oxygen
Contains
In lungs
Plasma
OXYGENATION AND DEOXYGENATION
Arterial Blood
Venous Blood
Which includes
Oxyhemoglobin (Scarlet Cruorine)
Deoxyhemoglobin (Purple Cruorine)
In tissues
Clotting Factors
Reversible dissociation
Mimics
Water
Oxygen
Such as
H2CO3
Fibrinogen
O2
In tissues
H2O
Reduced Carbon (Food)
Heat, Acid, Ethanol decomposition to form
Carbon Dioxide
Is a
irreversible
Protein Precipitate
Reducing Agents
Oxidized Products
CELLULAR RESPIRATION
Colored Compound
Heme
Mimics
Is a
BIOLOGY
slow
Spontaneously reacts with oxygen forming
Has a distinctive
SnII
SnIV
Is a
Brown Hematin
Acid Ether
Soluble in
Absorption Spectra
fast
FeII
FeIII
Stabilized by
2H
Observable with a
Concept map illustrating the relationships among
significant words and ideas in the Stokes article.
Tartaric Acid
Anionic Hematin
Aqueous Base
Soluble in
Spectroscope
Colorless Product
Indigo
HEMATIN FORMATION AND SEPARATION
OXIDATION AND REDUCTION REACTIONS
Oxygen
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Introduction to BiochemistryStudent Perceptions
1995-2000A. Consider items 1 through 12 and
rate them with respect to how important they are
for success in CHEM-342, Introduction to
Biochemistry. (1 Extremely Important º 5
Not Important N 159 out of 163)
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Introduction to BiochemistryStudent Perceptions
1995-2000B. Consider the items 1 through 12 in
relation to other science courses. Circle those
items which, in your experience, are more
important in CHEM-342 than in most other science
courses you have taken. (N159)
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Learning Issue Matrix
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Acknowledgements

• National Science Foundtion
• Fund for Post-Secondary Education
• Howard Hughes Medical Institute
• Pew Charitable Trusts
• University of Delaware - Administration, Faculty,
  Staff, and Students

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u/pbl/