Students' interdisciplinary reasoning about "high-energy bonds" and ATP

Abstract

Abstract. Students' sometimes contradictory ideas about ATP (adenosine triphosphate) and the nature of chemical bonds have been studied in the biology and chemistry education literatures, but these topics are rarely part of the introductory physics curriculum. We present qualitative data from an introductory physics course for undergraduate biology majors that seeks to build greater interdisciplinary coherence and therefore includes these topics. In these data, students grapple with the apparent contradiction between the energy released when the phosphate bond in ATP is broken and the idea that an energy input is required to break a bond. We see that students' perceptions of how each scientific discipline bounds the system of interest can influence how they justify their reasoning about a topic that crosses disciplines. This has consequences for a vision of interdisciplinary education that respects disciplinary perspectives while bringing them into interaction in ways that demonstrate consistency amongst the perspectives.

Oersted Lecture 2013: How should we think about how our students think?

“…75 As part of this effort, we have been holding extensive conversations with biologists, 76 interviewing both students and faculty about their views of the relations between physics and biology, and observing our students both working on physics problems in biological contexts 77 and exploring biological situations from a physics point of view. 78 One thing that we have learned from our interdisciplinary conversations: Biology and physics faculty look at the goals and approaches towards introductory instruction in their discipline in dramatically different ways.…”

Chemical energy in an introductory physics course for the life sciences

“…Later in the series, the students are given a potential with multiple wells of different depths. This is used as an analogy for chemical reactions that involve going from one bound state to another, and helps students reconcile how it is that breaking a bond (such as in ATP 30 ) can lead to the release of energy (because other stronger bonds are formed). Unlike the single well (as in Fig.…”

“…7, that has students engage in interdisciplinary reconciliation around ATP hydrolysis. 37 As shown in the figure, the students are given two different representations: a potential energy diagram for a general chemical bond, and a chemical equation for this reaction showing the structure of each molecule. Students are asked to reconcile the idea (useful in biology) that the O-P bond in ATP is called a "high-energy bond" 38 because a large amount of energy is released when ATP is hydrolyzed, with the idea (based on modeling chemical bonds with potential energy) that an input of energy is required to break the bond.…”

Ontological metaphors for negative energy in an interdisciplinary context

“…electrostatic interactions based on Coulomb's Law) with canonical chemistry and biology models of bonding and chemical reactions (e.g. attending to overall energy changes in a reaction [3]). We have argued here that this goal changes the pedagogical considerations and conclusions regarding ontological metaphors for energy that are supported in the instructional context.…”