Chemistry, Life, the
Universe and Everything
Melanie Cooper
Department of Chemistry, Clemson University
Michael Klymkowsky
Bioliteracy Project
Molecular, Cellular & Developmental Biology
University of Colorado, Boulder
CLUE: A New General Chemistry
Curriculum
Why?
Who are the students in our chemistry
courses?
Nationally > 50% students in general
chemistry are in bio-oriented majors.
Many take chemistry (only) because
medical professions require it.
Biology-related majors enrolled in Organic
Chemistry, Clemson, Fall 2008
And
most of
these are
Pre-med
Let’s face it: chemistry has a bit of an
image problem
“Chemistry is the subject that at least 6 out of every
6.0225 Americans insist they “flunked in high school”.
The boilerplate evil scientist of Hollywood is often
some type of chemist….. People rant against all the
“chemicals” in the environment ……”
“Chemists may be thought by adult survivors of high
school to have the sex appeal of a cold sore”
Angier, N. (2007). The canon: A whirligig tour of the beautiful basics of
science. New York: Houghton Mifflin.
Is there a conspiracy involved?
“There seemed to be a mystifying universal conspiracy among textbook
authors to make certain the material they dealt with never strayed to the
realm of the mildly interesting and was always a long distance phone call
away from the frankly interesting”
All mine (science texts) were written by men (it was always men) who
held the interesting notion that everything became clear when expressed
as a formula and the amusingly deluded belief that the children of
America would appreciate having chapters end with a series of questions
they could mull over in their own time. So I grew up convinced that
science was supremely dull…… “
Bryson, B. (2003). A short history of nearly everything. NY, NY.
And yet…
“The chemist’s world is the world around us, a
pampered stratum of relatively mild temperatures, and
manageable atmospheric pressure, and liquid water in
abundance”
“From the 115 elements you can build a near infinity of
molecules, of any type you need, to get all the
structural and functional diversity you can ask for.
There are at least 100,000 different molecules in the
human body. Some 900 volatile aroma components
have been found in wine. Chemistry is molecules. We
are molecules. Chemistry is a truly anthropic science.
Roald Hoffman quoted in “The Canon”
General Chemistry Courses Emphasize
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Stoichiometry, Stoichiometry, Stoichiometry
The structure of atoms
Bonding
Inorganic Reactions (precipitations)
Equilibrium, Equilibrium, Equilibrium
Perhaps the grim death march through units,
measurement, and stoichiometry is not as productive or
engaging as we might hope?
Sadler, J.R.S.T 2005 42, 987, Science 2007, 317, 457
Why are we squandering our
opportunities to engage students
with our subject?
Research (and experience) suggests that
students get “turned off” during general
chemistry (especially the second
semester)
Grove, N.P.; Bretz, S.L. J. Chem. Educ., 2007, 84(9), 1524-1529
Two questions:
What should students be learning?
Are they learning it?
Biological systems involve
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•
•
•
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Relatively few elements / bond types
Relatively few reaction types
Constrained reaction conditions
Coupled, non-equilibrium systems
Intermolecular interactions (surface properties)
Hydrophobic effects (self-assembly/folding)
Are they learning what we teach?
Many biology faculty do not apparently think
so, since they “re-teach” basic chemistry in a
week or two.
Why? Don’t students already know this material?
Growing body of education research suggests that they do
not (at least not confidently enough to use it)
Calls for reform are not new
Havighurst, R. J. (1929). Reform in the chemistry
curriculum. J.Chem.Educ., 6, 1126.
National Research Council. (2003). Bio 2010:
Transforming undergraduate education for future
research biologists. The National Academies Press
Nameroff, T. J., & Busch, D. H. (2004). Exploring
the molecular vision. J.Chem.Educ., 81, 177.
Core principles of student learning
• Identify and
address pre/misconceptions
• Knowledge of how
science is done
• Metacognition
• Context
National Research Council. How people learn: Brain, mind, experience, and
school (2001). Bransford J., D., Brown A., L. and Cocking R., L. (Eds.), .
Washington DC: National Academies Press
Current Gen Chem (and lets face it
most chemistry) texts
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•
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Not based on research on learning
Difficult to read/bloated and full of “asides”
No narrative theme (reason to read)
No efficacy data (in fact evidence that they
don’t produce meaningful learning)
• Attempt to teach process skills by using the
wrong medium
A researchbased,
integrated
curriculum based on
emergence and
evolution of life
Goals
Engaging Text
Researchbased Learning
Objects
Assessments
Interactive Materials
Tutorials (skills) eg
Lewis structures,
dimensional analysis
Tutorials (deductive)
e.g. structure
property
relationships
Assessments,
Formative and
Summative
Applets (inductive)explorations of
concepts), eg
bonding/energy
Research Base: existing and
proposed research on student
learning:
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Conceptual development
Problematic Pre-/Misconceptions
Development of problem solving expertise
Assessment
Conceptual Change
What chemistry concepts are important in
biology? (and do chemistry students
understand them?)
Can we address both these and core chemistry
concepts?
What order should concepts/skills be
introduced?
What is fundamental/foundational and what
“can wait”?
How to identify and address misconceptions?
Research into student thinking and language / Concept
Inventories elicit pre-/misconceptions
Research-validated applets – allow students to explore
bond formation and breaking and the accompanying
energy changes.
ConcepTests, conceptual assessments – check for
understanding (not pre-post)
Preliminary work
Bond Energy (source of
chemical energy)
Hydrophobic effect – driver for
protein/nucleic acid folding,
Molecular interactions, and
micelle/bilayer formation
Chemical Energy
• How do students develop understanding about
chemical energy/entropy/enthalpy, equilibrium,
non-equilibrium, coupled reactions?
• Central role of bond energy – bond making and
breaking
• Many misconceptions are didaskalogenic
(instruction-induced), since students have no
experience with bonds/reactions/etc.
Ed’s Tools – gather student language, begin to map student
thinking
http://bioliteracy.net (get an account)
https://solarsystem.colorado.edu/conceptInventories/
Sample open-ended questions
Describe what happens in terms of energy changes during
bond formation and breaking.
Describe the energy changes involved in the following
chemical reactions:
(a) CCl3F(g)  C(g) + 3Cl(g) + F(g)
(b) Na(s) + ½ Cl2(g)  NaCl(s)
Sample Concept Inventory Question
Which of the following statements describes the energy
changes during bond formation and breaking?
a) The energy released from bond breaking and formation is
remarkable.
b) During bond formation, energy is applied into the reactant molecules
so that their electrons will move around in order to form product
molecules.
c) During bond formation energy is released while during bond
breaking energy is consumed.
d) The reactant molecules absorb energy from their constituent atoms to
form product bonds.
e) Energy is released when bonds in the reactants are broken and energy
is required to build bonds.
General Chemistry Students (%) with Misconceptions
about bond energy and its role in chemical reaction
Misconceptions
% Students
Pre-instruction
Post-Instruction
Bond breaking/ making
69
50
Charge and electrons
44
7
Confusing/
contradictory
25
43
Bond-energy Concept Inventory Results
% Students by type with bond energy misconceptions
Chemistry level (#)
%
General Chemistry (77)
50
Inorganic (13)
54
Organic (172)
65
Analytical (35)
51
Physical (16)
56
Graduate Students (21)
68
Chemistry Post-docs
What happens to
the potential energy
when two hydrogen
atoms come
together
After
interaction
with the
“bonding
applet”
Hydrophobic Effects
Entropy driven
Micelle
formation
Protein folding
Oil and water
Ed’s Tools question:
Why Don’t Oil and Water Mix?
“Oil is not soluble in water, this is the main
reason why water and oil do not mix. When
mixing the oil and water, the oil will not
disperse throughout the water.”
Oil and water
Reason
% Preinstruction
% Post
instruction
% graduate
students
Density
33
24
40
Words without explanation
(intermolecular forces,
hydrophobic, “like dissolves like”)
76
71
60
Oil and water repel
38
18
20
Intermolecular forces cant be
overcome/energy (Δ H)
10
12
20
# of students who give correct explanation (Invoke G or
Entropy) = 0
Why don’t oil and water mix?
A. Like dissolves like
B. Oil and water have different densities which
causes them to separate.
C. There are no attractive forces between oil
molecules and water molecules, and therefore
the hydrogen bonds between water molecules
would require too much energy to break.
D. The entropy of the system is higher in the
unmixed state, because non-polar molecules
cause water molecules to cluster around them.
E. Oil molecules repel water molecules
Chemistry Post-docs
Development of structure-property relationships:
using range of interactive tutorials
Macroscopic
Particulate
Symbolic
Structural
C&LL Products
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Text
Interactive applets,tutorials, simulations
Concept inventories for “foundational ideas”
Formative and summative (ACS) assessments
NSF
Santiago Sandi-Urena
Nathaniel Grove
Todd Gatlin
Sonia Underwood
Alma Gonzales
Acknowledgments
• Alma Gonzales
• Sonia Underwood
• Nathaniel Grove
Problem solving “plan” from a general chemistry text
Many (most?) Introductory Level Biology
Courses Include:
• Equilibrium and non-equilibrium thermodynamics,
• Entropy-driven reactions
• Weak acid-base reactions
• Redox reactions
• Electrochemical gradient dynamics
• Catalysis and enzyme kinetics
• Protein folding
• Dynamics of molecular interactions
Which of the following statements describes the energy changes
involved in this chemical reaction
F
I
Cl – C – Cl (g) →
C(g) + 3Cl(g) + F(g)
I
Cl
a) The potential energy stored up in the reactant is released when it is
converted into atomic gases.
b) The energy originally in CClF3 splits into three parts and is
dispersed into the three elements.
c) The energy of the reaction does not really change since all the
products remain gases and the number of atoms after the separation
is the same as when they were together.
d) As the reactant is converted into products, energy is absorbed
to break bonds in the reactant.
e) The decomposition is caused by heating up such as in boiling
which would break the bonds holding the reactant together.
C&LL Proposed Materials
• Based on research on learning
• Engaging Text – theme emergence and
evolution of life
• Efficacy data will be provided
• Attempt to teach process skills will be
developed via interactive materials