Two students discussing the process of ATP hydrolysis (ATP + H2O ADP + Pi) make the following comments: Justin: “The O-P bond in ATP is called a ‘high-energy bond’ because the energy released when ATP is hydrolyzed is large. That released energy can be used to do useful things in the body that require energy, like making a muscle contract.” Kim: “I thought chemical bonds like the O-P bond in ATP could be modeled by a potential energy curve like this, where r is the distance between the O and the P. If that’s the case, then breaking the O-P bond in ATP would require me to input energy. I might not have to input much energy to break it, if that O-P happens to be a weak bond, but shouldn’t I have to input at least some energy?” How did Kim infer from the PE graph that breaking the O-P bond requires an input of energy? Who’s right? Or can you reconcile their statements?
NEXUS/Physics: Rethinking Physics for Biology and Pre-‐med Students Edward F. Redish1, Chris Bauer3, Karen Carleton1, Todd, Cooke1, Melanie Cooper4, Catherin Crouch5, Benjamin W. Dreyfus1, Benjamin D. Geller1, Julia Gouvea1,2, John Gianini1, Mike Klymkowsky6, Wolfgang Losert1, Kim Moore1, Joelle Presson1, VashV Sawtelle1, Katrina Thompson1, Chandra Turpen1, Royce Zia7
1 University of Maryland, College Park 2 University of California, Davis 3 University of New Hampshire 4 Michigan State University 5 Swarthmore University 6 University of Colorado 7 Virginia Tech
A Team of Interdisciplinary Experts NEXUS/Physics: Using a Research & Design Approach to Build an Interdisciplinary Course
References [1] NRC: Commi`ee on Undergraduate Biology EducaVon to Prepare Research ScienVsts for the 21st Century, Bio 2010: Transforming Undergraduate Educa8on for Future Research Biologists (Natl Academy Pr, 2003). [2] Scien8fic Founda8ons for Future Physicians: Report of the AAMC-‐HHMI Commi`ee (AAMC/HHMI, 2009). [3] Watkins, Coffey, Redish, & Cooke, “Disciplinary AuthenVcity: Enriching the reform of introductory physics courses for life science students”, Phys. Rev. STPER, 8, 010112. [4] Meredith & Redish, ReinvenVng Physics for Life Science Majors, Physics Today 66 (2013) 38. [5] (authors of this poster) “NEXUS/Physics: An interdisciplinary repurposing of physics for biologists,” to be published in Am. J. Phys. (summer 2014) [6] Svoboda, Sawtelle, Geller, & Turpen, “A framework for analyzing interdisciplinary tasks: ImplicaVons for student learning and curricular design,” CBE-‐LSE 12 (2013) 187. [7] Moore, Gianini, & Losert, “Toward be`er physics labs for future biologists,” to be published in Am. J. Phys. (summer 2014) [8] Dreyfus, Geller, Gouvea, Sawtelle, Turpen & Redish, “Chemical energy in an introductory course for the life sciences,” Am. J. Phys. (2014) in press
Acknowledgments This work is supported by the NSF Graduate Research Fellowship (DGE 0750616), NSF-‐TUES DUE 11-‐22818, and the HHMI NEXUS grant. Many thanks to the University of Maryland Physics EducaVon Research Group (PERG) and Biology EducaVon Research Group (BERG). Contact: [email protected]
Change of Topics from a TradiVonal Introductory Physics Class Goals for the Course
An Examples of New Content: Understanding Chemical Bond Energy [8]
Coherence-‐seeking between • Physics topics (“crossing chapters”) • Physics, biology, and chemistry • Physics and everyday knowledge (“feet on the ground”)
Meta-‐representaVonal competence
• RepresentaVon translaVon • Choosing when to make representaVons • How representaVons display informaVon • Building mathemaVcal competence:
Thinking with mathemaVcs
Modeling • Being explicit about modeling and models • System schema • ExplicaVng the value of “toy models”
• Redesign the physics for biologists course so that it has authenVc value for biology students – in both content and skill development [3][4][5]
• PosiVon the course within the biology curriculum • Assume will be taken in the second year • Chem, Bio, and Calculus as prerequisites
• InnovaVve content focused on the need to support student learning
• View the development as an iteraVve process where research with student response to the curriculum informs what we do in the next iteraVon [6]
• Maintain criVcal components – quanVficaVon, mathemaVcal modeling, mechanism, mulVple representaVons and coherence (among others)
Development Team
Off-‐Campus
Collaborators On-‐Ca
mpus D
iscussa
nts
• 7 Physicists • 4 Biologists • 3 Biology EducaVon
Specialists
• 3 Physicists • 4 Biologists • 2 Chemists • 3 EducaVon
Specialists (Phys, Bio, Chem)
• 7 Physicists • 1 Biologist • 2 Chemistry
EducaVon Researchers
Expand the treatment of thermodynamics
Include atomic and molecular examples from the beginning
Eliminate rotaVons, angular momentum and magneVsm
Light Intro Waves Thermo Electricity Exam 1 Ex 2 Light
How a Kinesin walks
Membrane 1 Nernst equaVon
Diatomic VibraVons
IntroducVon to opVcs
DNA SalVng Out
What’s “free” about free energy?
Membrane 2 Vision Pulses and
SHO
PE analogs for chem.
rxns
Fields and potenVals
Capacitance in
Nerve Cells
DNA Shielding
Enthalpy of simple
molecules
Evap. Membrane
Polymer folding / EvoluVon
Micro-‐ scope
Modeling chromophores
DNA and photons
Biology-‐linked Group Problem-‐Solving Tasks
Biology components of HW Assignments
Macro KinemaLcs Math Energy Thermodynamics Dynamics Dynamics Exam 1 Exam 2
Scaling a Worm
MoVon of a vesicle
Exam Review Arteries / Speed of blood
PIP2 Water coat force / DNA charge
Wood-‐pecker
Exam Review
Moving a Para-‐
mecium
Blood and Breath
Diffusion
Muscle Contract / Thermal-‐chemical
Bound States /
Deeper Well None
Cat & Antelope
Protein Unfolding
Gas properVes & pressure
FricVon Problems
Force Problems
Micro-‐states Temp.
RegulaVon Energy Skate
Park
Biology components of HW Assignments
Biology-‐linked Group Problem-‐Solving Tasks
Semester 1
Semester 2
Include discussions of kineVc theory, diffusion, and randomness
Responding to a Call for Change
• Biology students are becoming a significant proporVon of the service load of a physics department – enough that we should provide a course that meets their needs.
• Biologist are calling for [1][2] • Be`er development of
scienVfic competencies • More coherence among the disciplines
• Project NEXUS – A mulV-‐university demonstraVon project created by HHMI to provide science courses for a biology major • Physics (UMCP) • Chemistry (Purdue) • Math for Bio (UMBC) • Capstone Synthesis (Miami U)
New Laboratories [7]
• Develop student research skills • Focus on Sensemaking • Focus on Experimental Design • Focus on the Value of
QuanVficaVon • Convey a modern view of physics
• Use modern equipment and tools • Foster interdisciplinary transfer
• “What biology do you learn from a physical measurement?”
For more info: hNp://nexusphysics.umd.edu
The chemical reacVon of ATP hydrolysis is the primary source of energy in basic biological metabolic processes. Pusng in a small amount of energy allows one to break a phospate bond in ATP. That phosphate then bonds with the surrounding water, forming a strong bond and releasing usable energy.
Biology students all know that “ATP is the currency of biological energy” but oten have a weak understanding of mechanism. Many think bonds “store” energy and release it when broken (“Piñata model”). We build the connecVon from basic physics concepts to help them understand chemical bonding and exothermic reacVons in a more effecVvely.
Exam essay ques+on
How Big is a Protein
The DNA spring
Electric forces:
H bonding
Electro-‐phoresis
Cell polarizaVon (diffusion)
Fluid flow in arteries
Exam Review Exam Review
Moving through a cell /Listeria
Random walk and entropy
Photosyn-‐thesis
Spectroscopy Light/ma`er interacVon
Electric circuits
Membrane model
VibraVons
Fourier construcVon of wave shapes
