Examining and Supporting Mechanistic Explanations Across Chemistry and Biology Courses.

Causal mechanistic reasoning is a thinking strategy that can help students explain complex phenomena using core ideas commonly emphasized in separate undergraduate courses, as it requires students to identify underlying entities, unpack their relevant properties and interactions, and link them to construct mechanistic explanations. As a crossdisciplinary group of biologists, chemists, and teacher educators, we designed a scaffolded set of tasks that require content knowledge from biology and chemistry to construct nested hierarchical mechanistic explanations that span three scales (molecular, macromolecular, and cellular). We examined student explanations across seven introductory and upper-level biology and chemistry courses to determine how the construction of mechanistic explanations varied across courses and the relationship between the construction of mechanistic explanations at different scales.

How Do Instructors Explain The Mechanism by which ATP Drives Unfavorable Processes?

Concerns regarding students' difficulties with the concept of energy date back to the 1970s. They become particularly apparent for systems involving adenosine triphosphate (ATP), which plays a central role in maintaining the nonequilibrium state of biological systems and in driving energetically unfavorable processes. One of the most well-documented misconceptions related to ATP is the idea that breaking bonds releases energy, when the opposite is true.