Integrating research on student understanding of protein structure with implementation of a biochemistry laboratory experiment: Circular dichroism of globular proteins
Authors: Lewis Christopher , Nguyen Minh‐Tuan , Texter Frieda , Schlessman Jamie L , Teichert Melonie 
Published: November 2023

The importance of protein structure and function concepts has been identified in a set of foundational concepts and skills for majors in biochemistry and molecular biology; these are also included in the recommended curriculum of this society. Further, researchers have identified threshold concepts for biochemistry that include: (1) the physical basis of interactions, relating to the electrostatic interactions that govern structure; and (2) thermodynamics of macromolecular structure formation, including protein folding. At the same time, biochemistry educators have begun to investigate student understanding of protein structure and related function and have documented student difficulty with levels and representations of protein structure. Specifically, researchers have identified problems with molecular visualization and external representations, and small‐scale interviews have indicated that students are better at recognition and identification tasks relating to secondary protein structure than they are at drawing or generating their own representations. Coincident with the documentation of student difficulties has been the community's development of instructional materials to facilitate student learning of the concepts. Those in the literature thus far focus on classroom‐based activities. This poster presents work to incorporate a laboratory experiment that utilizes modern experimental methods (circular dichroism (CD) spectroscopy) to enhance evidence‐based student learning.

This project includes research on student learning in our current biochemistry sequence that will inform the development of our laboratory materials. The research aspect of this work will present student conceptions of protein structure as measured on written final exams. Our research cohort includes 109 students from 6 semesters of the biochemistry course. Analysis to be presented includes students’ detailed explanations of (a) protein structural hierarchy, (b) denaturant effects, (c) the thermodynamic basis of protein folding, and (d) the effects of various amino acid substitutions on structure. The procedural aspects of the lab are based on published and unpublished existing laboratory experiments to study globular proteins using circular dichroism and modified to match our pedagogical goals and instrumentation constraints. As part of the lab, students are able to explore the difference between far UV CD spectra for alpha‐helical, beta sheet, and mixed secondary structure and to study solvent effects. The pedagogical aspects of our laboratory development seek to specifically address the misunderstandings observed in our analysis of student exam data, and to incorporate evidence‐based practices such as eliciting students’ initial ideas, helping students to make their mental models explicit, using multiple external representations, and prompting students to revise their ideas in light of experimental evidence.