Connecting Chemistry: Using Green Chemistry and Health to Show Students Why Stereochemistry Matters

[ACSGCI]

Contributed by Kendra Leahy Denlinger, Teaching Professor at Xavier University; Rebecca Haley, Assistant Professor at University of Wisconsin-River Falls; and Heather Hopgood, Assistant Professor of Instruction at Ohio University

Working together to connect chemistry

What do women’s health and health inequity have to do with the ability to identify a stereogenic center? This was a question we set out to answer as we began our journey with the Green & Sustainable Chemistry Education Module Development Project. Before diving into how we have attempted to answer this question, let’s go back to a scenario you may have encountered in the classroom.  Every now and then, chemistry educators get the bold student who speaks on behalf of the class: “Why does this matter?” with the accompanying sigh and eye-roll. In the past, we have answered this question with some broader picture context and the obvious “you’ll need it for your next course.” This answer isn’t all that satisfying for us, or the students.

What we would really like is to offer the opportunity for students to cultivate their own understanding of how chemistry is connected to their passions, other disciplines, and society at large. However, addressing this part of chemistry is challenging given an already packed curriculum. It often feels like there is only enough time to cover the traditional content details and never enough time to connect those details to other areas of life. This lack of time and resources does not even address the other issue, which is that students tend to struggle due to insufficient background knowledge and skills while trying to master a difficult course. While it is undoubtedly important that we support our students through these struggles, to truly prepare them for the next stages of their careers, it is essential to find a way to incorporate how chemistry is connected to “the big picture.”

When the ACS Green Chemistry Institute (GCI) extended the opportunity to develop classroom materials that would intertwine the typical chemistry content with green chemistry, systems thinking, and the UN Sustainable Development Goals, we were ecstatic. Suddenly we were being given the time, space, and permission to present the chemistry content through the lens of its importance and connection to relatable global issues. Once we got started, though, the questions of “how do we do this?” and “what is systems thinking, really?” quickly emerged. While we have the desire to teach our students how to connect chemistry to important real-world systems, we were not taught that way. It seems we had some learning to do ourselves. Fortunately, the GCI has a leadership team to help guide us along the way. Their expertise has complemented our roles as organic chemistry educators and allowed us to develop our first module in a way that is true to the organic content but through the important lens of green and sustainable chemistry.

Finding the relationship between health inequities and stereochemistry

As three women who teach organic chemistry, we were particularly interested in developing a module that would encourage our students to think about how chemistry impacts inequities in our social systems. We were also interested in tackling a topic that is essential to the foundation of organic chemistry - stereochemistry. The overlap of these two subjects seemed most natural to address UN Sustainable Development Goal #3 - Good Health and Well Being.

It is relatively common to introduce the importance of stereochemistry with pharmaceuticals that are sold as a single enantiomer because one of the enantiomers in the racemic mixture is harmful to the human body (e.g. naproxen). What is not often discussed is the impact synthesizing a single enantiomer may have on access to essential medicines. To incorporate more of this thinking, we integrated the World Health Organization’s (WHO) Model List of Essential Medicines throughout the entire stereochemistry module. Various types of medications are included throughout the module: NSAIDs, anti-epileptics, antibiotics, antimalarials, and others. However, instead of simply using ibuprofen as an interesting example of a chiral molecule, we guide the students toward a discussion of why ibuprofen and aspirin are on the WHO Model List of Essential Medicines while sodium naproxen is not. We hope that students will consider that sodium naproxen may be more expensive (and therefore less accessible for underserved populations) because only the S-enantiomer is anti-inflammatory, while the R-enantiomer is a liver toxin, necessitating that S-naproxen be isolated or synthesized as a single enantiomer.  On the other hand, ibuprofen can be sold as a racemic mixture and aspirin is simply achiral. After learning and studying stereochemistry with the focus on the human body and healthcare systems, we focus on UN Sustainable Development Goal #5, Gender Equality, in the module’s summative assessment. In this assessment, students consider inherent inequalities with respect to reproductive health, pregnancy, and childbirth. Too many women die each year due to complications surrounding pregnancy and childbirth, and this rate is especially high in low-resource settings. Students use examples from the WHO model list to demonstrate their understanding of chirality while also considering the importance of access to medications used for postpartum bleeding, postpartum infections, and oral contraceptives. 

We are eager to pilot this module in our classes beginning this fall, where we will be assessing the results of the module activities and assessments, and revising accordingly.

Adopting the module

For those of you who are thinking “that module sounds great, but there’s no way I could fit it into my already packed curriculum,” we have had those thoughts. We have been to the conferences that left you energized and had the conversations with colleagues that empowered you—only to realize how much time and energy it takes to actually do the work that makes it possible to replace the current content you are teaching. We have been there, so we worked hard to make this module an alternative to the class content you are teaching—not an extra to the content you are teaching. We all want our students to create and build their critical thinking skills in a way that is meaningful beyond just the chemistry content itself. We hope that adopting this module will be an easy way to do that. We designed it to be low-stakes for your time, but high-impact for your students. After we do our final pilots and incorporate revisions, you will be able to find it on the GCI website. We are aiming to have it available for you for the Fall of 2022. We hope you will consider adopting it, whether it is the whole module or just part of it.