Process Oriented Guided Inquiry Learning (POGIL) is an effective approach for group work in STEM courses. POGIL-style lessons foster active learning because they require students to communicate and co-construct knowledge to solve problems. Here, we have designed a POGIL problem set to help students learn about experiments that led to discoveries about protein import into the endoplasmic reticulum (ER). Approximately 30% of all known proteins get imported into a cell’s ER, where they either stay or travel to another location in the secretory pathway. Because this initial localization to the ER is shared amongst all secretory proteins, it is important for cell biology students to understand the mechanism of ER import. Our problem set directs students to answer questions about how an ER import assay works and how the channel for import (known as the translocon) was discovered. This lesson has been used over 100 times at our institution, where students and instructors alike have found it to be successful in solidifying students’ knowledge of ER import and facilitating students’ experimental design skill development.

Primary Image: Protein import into ER: The image shows a protein being inserted into the ER through the translocon.

Osmosis contributes to a range of biological phenomena, from functioning of nephrons in animals to stomatal opening and closing in plants; yet, scientifically simple ideas about osmosis are common. These ideas limit learners’ comprehension of biological processes involving osmosis. They limit, too, science graduates’ potential to contribute to the ecosystem of innovation, which has turned to osmosis for desalinating water and harvesting “blue energy,” for example. To deepen conceptual understanding of osmosis, this ~50-minute lesson asks students to analyze tabulated data, a graph, and photomicrographs related to osmolality of personal lubricants and then to formulate a scientific recommendation for the bulk procurement of personal lubricants. The lesson takes inspiration from an expert review panel convened by the World Health Organization to generate such a recommendation. The lesson includes at its start a consideration of diffusion. This inclusion allows a contrast between osmosis and diffusion to be drawn. The inclusion also deepens students’ understanding of stochastic processes in biology. We have used the lesson in an introductory undergraduate biology course and an upper-level one. Quantitative assessment data were collected from the latter and documented students’ adoption of scientifically rigorous views of osmosis and diffusion. Qualitative data collected from both courses revealed that students found the lesson personally relevant and its information surprising. Students were struck by the apparent inattention to women’s physiology in the design of lubricant. This surprise suggests ways to extend the lesson, for example, into the nature of science, in particular, into the social and cultural embeddedness of science.

Primary Image: Trajectories of three diffusing mastic particles overlying “Diver and Two Octopi.” “Diver and Two Octopi” comes from Kinoe no komatsu, volume 3 (Katsushika Hokusai [Japan, 1760–1849], 1814. Woodblock print. British Museum, asset number 583055001; © The Trustees of the British Museum, who permit use of image under terms of CC BY-NC-SA 4.0). Trajectories (in white) adapted from Figure 6 of “Mouvement Brownien et Réalité Moléculaire” (J. Perrin, Annales de chimie et de physique: tome XVIII. Paris: Gauthier-Villars, 1909. Source: gallica.bnf.fr / Bibliothèque nationale de France).