Classic Research Articles as Classroom Texts for PBL in Undergraduate Biochemistry Hal White Dept. of Chemistry and Biochemistry University of Delaware.

Classic Research Articles as Classroom Texts for PBL in Undergraduate

Biochemistry

Hal WhiteDept. of Chemistry and Biochemistry

University of Delaware

16 June 2012University of Michigan – Dearborn

ASBMB NSF-RCN Meeting

Introductory Science Courses Stereotype

1. Lecture format that is content-driven.

2. Abstract concepts introduced before concrete examples.

3. Enrollments often more than 100.

4. Limited student-faculty interaction.

5. Grading based on a few multiple choice examinations that emphasize recall of information.

6. Reinforce intellectually immature students to a naïve view of knowledge.

Common Features of aProblem-Based Approach to Learning

• Learning is initiated by a problem• Problems are based on real-life, open-ended

situations, sometimes messy and ill-defined.• Students identify and find the information

necessary to solve the problem using appropriate resources.

• Students work in small permanent groups with access to an instructor.

• Learning is active, integrated, cumulative, and connected.

What Does a PBL Classroom Look Like?

Overview of This Presentation

• The Case for Classic Articles as PBL Problems

• Example of an Article-Based Course • Experience a Classic Article Problem• Designing a Course Around Classic

Articles• Student Response

Characteristics of Good PBL Problems

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

Classic Articles as PBL Problems

Advantages

• Authentic (not contrived)

• Complex

• Relevant to the Discipline

• Introduce Important Historical Figures

• Encourage use of Internet Resources

Science as Literature?

“There is no form of prose

more difficult to understand

and more tedious to read that

the average scientific paper.”

Francis Crick (1995)

Science as Literature?

“I am absolutely convinced that science is

vastly more stimulating to the imagination

than are the classics, but the products of

this stimulus do not normally see the light

of day because scientific men as a class are

devoid of any perception of literary

form”

J. B. S. Haldane

Introduction to BiochemistryRelation to Other Science Courses

Biochemistry

BiologyChemistry

PhysicsMathematics

Provides the relevance

Provides the methods and molecular perspective

Provides the means toevaluate and predict

Provides physical models

NO NCH

NC N OC

H3C H3C

CH2

COO COO

CH3 CH3

CH2

H HH H H HH

Introduction to BiochemistryEvolution of the Course

1970's Course for non-science majors based on Herman Epstein’s 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.

Introduction to Biochemistry:

An Article-Based PBL Course

• 3 Credits, No Laboratory, 8:00 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

Stokes (1864)SpectroscopySolvent Extraction

Zinoffsky (1886)Elemental Analysis

Bohr et al (1904)Gas Laws

Herrick (1910)Medical Case

Diggs et al (1934)Epidemiology

Peters (1912)Stoichiometry

Conant (1923)Electrochemistry

Pauling & C (1936)Magnetic Properties

Adair (1925)Osmometry

Svedberg & F (1926)Sedimentation Eq

Individual and Group MidTerm Exam

Classic Hemoglobin Articles Read Before Spring Break

Concept Maps

Home Groups

Produce

“Jigsaw” Groups

Individual and Group Final Exam

Dintzis (1961)Direction Protein Syn

Pauling et al (1949)Electrophoresis

Ingram (1958/59)Peptide Sequencing

Allison (1954)Malaria Resistance

Shemin & R (1946)Heme Biosynthesis

HemoglobinopathyAssignmentGenetic MutationsProtein Structure

Classic Hemoglobin Articles Read After Spring Break

GroupWork

IndividualProject

Course Timeline

1850 1900 1950 2000

Stokes Zinoffsky

Adair

Peters

Pauling +

Pauling et al.

IngramAllison

HemoglobinopathyAssignment

Before Midterm

DiggsBohr

Shemin

Dintzis

After Midterm

Herrick

Conant

Svedberg

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.

Introduction to BiochemistryInstructional Goals For Students

1. Become intellectually independent learners2. Recognize and confront areas of personal ignorance3. Review and apply chemical, biological, physical, and

mathematical principles in a biochemical context 4. Improve problem-solving skills5. Create, understand, and value abstract biochemical models6. See biochemistry in relevant historical and societal contexts7. Discover and use the resources of the library and the Internet8. Gain confidence in reading and understanding scientific

articles9. Experience the powers (and pitfalls) of collaborative work10. Appreciate importance of clear oral and written communication 11. Learn to organize logical arguments based on evidence

Sir George Gabriel Stokes (1819-1903) became Lucasian Professor of Mathematics at the University of Cambridge in 1849. This prestigious professorship once was held by Sir Isaac Newton and now is held by Stephen Hawking. Like Newton, Stokes served both as president of the Royal Society (1885) and as a conservative member of Parliament (1887-1892)

Author of the first article students read.Known for:“Stokes Law”“Stokes Radius”“Stokes Reagent”“Stokes Shift”

Instructions for Stokes (1864)

In groups of two or three, consider the introductory section of the Stokes (1864) article.

Assignment: Make a list of the concepts and facts that your students would need to know (or review) in order to understand this section.

Oxidation and Reduction of Hemoglobin

CHEM-342 Introduction to Biochemistry

Question for Group Work on Midterm Examination

Prof. Essigsaure returned to his lab one night to prepare for a lecture demonstration based on the experiment presented in the second paragraph of Section 11 in Stokes’ 1864 article. Within minutes he was looking high and low for the glacial acetic acid and mumbling angrily about associates who don’t replace the things they use up. Frustrated, but undaunted, he figured any acid would do and substituted concentrated hydrochloric acid. After all, he reasoned, a stronger acid should work even better. — Not so. Sure enough the hemoglobin solution turned brown immediately upon addition of HCl but, much to his initial puzzlement, the resulting hematin did not extract into the ether layer.

Explain in chemical terms why HCl cannot be substituted for glacial acetic acid in

this experiment. Draw chemical structures and diagrams to support your argument. If you are uncertain of the explanation, please outline the possibilities you have considered or how you analyzed the problem.

Scarlet Cruorine Purple Cruorine

Brown Hematin Red Hematin

O2

+ O2

+H2CO3

H2OIrreversible

ReducingAgents

OxidizedProducts

O2

Reducing Agents

Acid, Heat,Organic Solvents

Albuminous Precipitate

Acid, Heat,Organic Solvents

Reversible

Irreversible Decomposition

Conceptual model for the reactions of “cruorine” described by Stokes. The color of the squares corresponds to the spectral properties of the compound involved.

Conceptual Representation of the Stokes (1864) Article

Reversible “Reduction” of Oxyhemoglobin

Add a small amount ofsodium dithionite,

Na2S2O4

Stir in the presence of air

O2 (g)

O2 (l)

HbO2 Hb SnII SnIVH2O

Air

Water 2. Shaking, rapid transfer

1. Diffusion, very slow transfer

Reversible binding

Irreversible oxidation

Constructing Models to Explain Observations

slow

rapid

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

BLOOD

Plasma

ClottingFactors

Fibrinogen

Colored Compound

AbsorptionSpectra

Spectroscope

Red Blood Cells

O2

Oxyhemoglobin(Scarlet Cruorine)

Deoxyhemoglobin(Purple Cruorine)

ArterialBlood

VenousBlood

BrownHematin

Heme

AnionicHematin

ProteinPrecipitate

OXYGENATION AND DEOXYGENATION

BLOOD TRANSPORTOF OXYGEN

HEMATIN FORMATION AND SEPARATION

OXIDATION ANDREDUCTION REACTIONS

CELLULAR RESPIRATION

CHEMISTRY

BIOLOGY

H2CO3

H2O

ReducingAgents

OxidizedProducts

Acid Ether

AqueousBase

Reduced Carbon(Food)

CarbonDioxide

SnII

FeII FeIII

ColorlessProduct

Tartaric Acid

Indigo

SnIV

WaterOxygen

Oxygen

Oxygen

irreversible

slow

fast

Stabilized by2H+

Spontaneously reactswith oxygen forming

Heat, Acid, Ethanoldecomposition to form

Reversible dissociation

Mim

ics

Mim

ics

In lungs

In tissues

In tissues

Lyse in waterto release

Contains

Contains

Has adistinctive

Observablewith a

Whichincludes

Suchas

Is a

Is a

Is a

Soluble in

Soluble inConcept map illustrating the relationships among significant words and ideas in Stokes’ 1864 article.

Group Quizzes with IFAT® Answer Sheets

• Multiple Choice Format• Lottery Ticket Design• Immediate Feedback• Partial Credit• Tremendous Discussion

Stimulator• Students Like It• Potential for Multiple Use

• http://www.epsteineducation.com/• BAMBED 33, 261-2 (2005)

Allison, A. C., (1954) Brit. Med. J. 1, 290-294 Protection Afforded by Sickle-Cell Trait Against

Subtertian Malarial Infection.

Question for group consideration and subsequent class discussion:

How might you demonstrate that people carrying one allele for sickle cell hemoglobin

have increased resistance to malaria?

Introduction to BiochemistryStudent Perceptions 1995-2004

A. 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 to 5 = Not Important; N = 263 out of 268)

Item

Mean ± SD

Item

Mean ± SD

1. Personal Initiative

1.47 ± 0.61

7. Prior Knowledge

2.83

± 0.97 2. Library Research Skills

1.88

± 0.80

8. Memorization

3.90

± 0.95 3. Taking Notes in Class

2.92

± 1.00

9. Learning New Information

1.61

± 0.77 4. Writing Skills

2.16

± 0.85

10. Problem Solving Skills

1.64

± 0.79 5. Collaboration with Classmates

1.55

± 0.76

11. Conceptualization

1.50

± 0.65 6. Oral Communication Skills

1.77

± 0.81

12. Attendance

1.43

± 0.69

Introduction to BiochemistryStudent Perceptions 1995-2004

B. 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. (N=263) Item

Percent

Item Percent

1. Personal Initiative

40.8

7. Prior Knowledge

12.1

2. Library Research Skills

60.0

8. Memorization

1.1

3. Taking Notes in Class

1.9

9. Learning New Information

14.8

4. Writing Skills

37.5

10. Problem Solving Skills

46.9

5. Collaboration with Classmates

72.7

11. Conceptualization

40.5

6. Oral Communication

Skills

57.8

12. Attendance

39.7

Effect of Facilitators on Attendance

Attendance before facilitators: 91.1%Attendance after facilitators: 94.1%

(32% reduction in absences)

Allen & White (2001). In, Student-Assisted Teaching,Miller, Groccia & Miller, Eds. Bolton, MA: Anchor.

Effect of Facilitators on Effort

Hours before facilitators: 4.8 per weekHours after facilitators: 6.0 per week

(25% increase in time spent on course work outside of class)

Allen & White (2001). In, Student-Assisted Teaching,Miller, Groccia & Miller, Eds. Bolton, MA: Anchor.

Performance Comparison on 21-item Pre-post Test on Chemistry Concepts Important in

Biochemistry

0 3 6 9 12 15 18 210

3

6

9

12

15

18

21Chart Title

Pre course Test Score

Pos

t co

urs

e T

est

Sco

re

Post > Pre test

Pre > Post test

Spring 2012

0 3 6 9 12 15 18 210

3

6

9

12

15

18

21

Pre-course Test Score

Pos

t-co

urs

e T

es S

core Post > Pre test

Pre > Post test

Ave 10.98 → 12.23Ave 9.60 → 12.92

Sophomore PBL Course Upper-Level Lecture Survey

Fall 2010

Course Elements Gains

All Others CHEM-342 Students

CURE Survey Results

Course Web-Site

Introduction to Biochemistry

www.udel.edu/chem/white/CHEM342.html