Classic Research Articles as Classroom

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Feb 22, 2014 (3 years and 4 months ago)

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Classic Research Articles as Classroom
Texts for PBL in Undergraduate
Biochemistry

Hal White

Dept. of Chemistry and Biochemistry

University of Delaware


16 June 2012

University 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 a

Problem
-
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 Biochemistry

Relation to Other Science Courses



Biochemistry

Biology

Chemistry

Physics

Mathematics

Provides

the relevance

Provides the

methods and

molecular perspective

Provides the means to

evaluate and predict

Provides

physical models

N
O
N
C
H
N
C
N
O
C
H
3
C
H
3
C
C
H
2
C
O
O
C
O
O
C
H
3
C
H
3
C
H
2
H
H
H
H
H
H
H
Introduction to Biochemistry

Evolution 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)

Spectroscopy

Solvent 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

Hemoglobinopathy

Assignment

Genetic Mutations

Protein Structure

Classic Hemoglobin Articles

Read After Spring Break

Group

Work

Individual

Project

Course Timeline

1850

1900

1950

2000

Stokes

Zinoffsky

Adair

Peters

Pauling +

Pauling et al.

Ingram

Allison

Hemoglobinopathy

Assignment

Before Midterm

Diggs

Bohr

Shemin

Dintzis

After Midterm

Herrick

Conant

Svedberg

Introduction to Biochemistry

Course 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 Biochemistry

Instructional Goals For Students

1.
Become intellectually independent learners

2.
Recognize and confront areas of personal ignorance

3.
Review and apply chemical, biological, physical, and
mathematical 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

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

O
2

+ O
2

+H
2
CO
3

H
2
O

Irreversible

Reducing

Agents

Oxidized

Products

O
2

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 of

sodium dithionite,

Na
2
S
2
O
4


Stir in the presence of air

O
2 (g)

O
2 (l)

HbO
2

Hb

SnII

SnIV

H
2
O

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

Clotting

Factors

Fibrinogen

Colored Compound

Absorption

Spectra

Spectroscope

Red Blood Cells

O
2

Oxyhemoglobin

(Scarlet Cruorine)

Deoxyhemoglobin

(Purple Cruorine)

Arterial

Blood

Venous

Blood

Brown

Hematin

Heme

Anionic

Hematin

Protein

Precipitate

OXYGENATION AND DEOXYGENATION

BLOOD TRANSPORT

OF OXYGEN

HEMATIN FORMATION

AND SEPARATION



OXIDATION AND

REDUCTION REACTIONS

CELLULAR RESPIRATION

CHEMISTRY

BIOLOGY

H
2
CO
3

H
2
O

Reducing

Agents

Oxidized

Products

Acid

Ether

Aqueous

Base

Reduced

Carbon

(Food)

Carbon

Dioxide

Sn
II

Fe
II

Fe
III

Colorless

Product

Tartaric Acid

Indigo

Sn
IV

Water

Oxygen

Oxygen

Oxygen

irreversible

slow

fast

Stabilized by

2H
+

Spontaneously reacts

with oxygen forming

Heat, Acid, Ethanol

decomposition to form

Reversible dissociation

In lungs

In tissues

In tissues

Lyse in water

to release

Contains

Contains

Has a

distinctive

Observable

with a

Which

includes

Such

as

Soluble in

Soluble in

Concept 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 Biochemistry

Student 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 Biochemistry

Student 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


4
6.9


5. Collaboration with

Classmates


72.7


11. Conceptualization


40.5


6. Oral
Communication

Skills


5
7.8


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 week

Hours 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
21
0
3
6
9
12
15
18
21
Post
course
Test Score

Pre
course
Test Score

Post > Pre test

Pre > Post tes
t

Spring 2012

0
3
6
9
12
15
18
21
0
3
6
9
12
15
18
21
Post
-
course
Tes

Score

Pre
-
course Test Score

Post > Pre test

Pre > Post test

Ave 10.98 → 12.23

Ave 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