Whatever Happened to the Organic Chemistry of Tomorrow?

WRITTEN BY YALE HUANG

ILLUSTRATED BY ANDREA ARMENDI

Thank you to Professor Jeremy Klosterman and Professor Valerie Schmidt for their vital insight into the changes made to the organic chemistry series!

The first time you sit behind the wheel of a car is an experience like no other. Maybe your first thought is, “Finally! Some real freedom!” Or maybe it’s, “I need to get an air freshener in here.” 

After all, driving in a simulation is nothing like driving on the road. The highway is an eight-lane nightmare, and you’re constantly surrounded by metal death traps and annoying pedestrians who wander onto the street with their eyes glued to their phones. The only thing stopping you from starting a Mario Kart-style pile-up on the I-5 is your instructor, the guiding angel in the passenger seat who hits the brakes when things get rough. 

The same can be said for organic chemistry. Having a patient professor with a well-structured curriculum is the difference between hating chemistry for the rest of your life or walking out of the final with a new appreciation for the function of the world. So when the Department of Chemistry and Biochemistry at UC San Diego rolled out drastic changes to the organic chemistry course in Fall 2022, dividing what had once been the CHEM 40ABC series into CHEM 40AB for biological sciences and CHEM 41ABC for physical sciences, many undergraduates were confused. Organic chemistry has long stood as one of the hardest classes in university, challenging students to adapt divergent thinking processes required in industry and post-graduate school. Was there a need to disrupt the status quo?

In short, yes.

At UC San Diego, the School of Physical Sciences encompasses everything from chemistry to astrophysics, while the School of Biological Sciences includes general biology, ecology, neurobiology, and more. With the variety of majors offered in both schools, students in each often have diverse interests and needs specific to their track. Whereas a chemistry major may take organic chemistry to delve deeper into the synthetic elements immediately applicable to their post-graduate education, a human biology major may take the course to satisfy an MCAT requirement. 

While this heterogeneity makes for a flourishing research institution, the original chemistry sequence struggled to accommodate these two dynamic student populations with distinct goals and passions. As a result, the pacing of the course was paradoxically too fast and too slow. Important connections between organic chemistry and biological mechanisms would be skipped, leaving biological science majors bewildered by the poor connection to their current coursework. At the same time, many topics intended to provide physical science majors with a foundation for upper-division coursework would be trimmed to avoid overloading biology majors with irrelevant content. 

This awkward compromise between chemical and biological concepts of organic chemistry caused students to engage less with the material. By attempting to accommodate both types of students, the original CHEM 40ABC series failed to satisfy either.

“[Professors] would go, ‘Well, we’d want to update the curriculum or textbook to help our [chemistry] majors, but the majority of our students are biology majors with different needs,’” says Professor Jeremy Klosterman, a professor in the Department of Chemistry and Biochemistry. As one of the professors who teaches the new CHEM 41 series, he helped organize the transformation from CHEM 40 and 40H to 41ABC. “So you’re kinda stuck in that one-size-fits-most, but not very well.”

Which brought up another issue with the original organic chemistry series: time. 

“We were trying to serve the chemistry and physical science majors, who need the traditional three-quarter organic chemistry series. But we were also trying to serve the much larger life science student body—biology—who only had to take two quarters of organic chem,” Professor Klosterman explains. “So we were under a massive time crunch to try to fit most everything in two quarters, but yet also teach in three quarters.” 

With various issues emerging from attempts to accommodate two student populations, the solution was obvious. Split the class in half, catering one towards biological sciences and the other towards physical sciences, reaping the rewards for both students and faculty. 

So that’s exactly what the department did! 

According to Professor Klosterman, the content of the curriculum underwent very little change. After all, organic chemistry remains a foundational science that introduces students to essential concepts such as chemical structure and reactivity predictions. “Whether it’s your flavor of chemistry, you’re still in the chemistry world,” he says. 

Instead, the department focused on structural changes. How should students from different STEM backgrounds approach organic chemistry? What learning outcomes will further student understanding? 

“The 40AB series tests student understanding of these concepts through the assessment of structure-function relationships and reactivity, whereas the 41ABC series focuses more on demonstrating understanding through synthesis,” says Professor Valerie Schmidt, who spearheaded the new curriculum for CHEM 40AB along with Professor Haim Weizman. She describes the distinction between 40AB and 41ABC as a matter of emphasis, not of content: “It is a fundamentally different framework through which organic chemistry is approached and, because of that, assessed.”

In the process, the dual series aims to address a bigger issue: the divide between physical sciences and biological sciences. By setting different learning outcomes for both types of students, professors are able to draw tailored examples from research and industry to engage students with topics relevant to their advanced coursework. 

“When everyone’s in the same class together, you can’t really teach either audience,” Professor Schmidt says. “By having the 41ABC [and 40AB dual] series, we can actually do really innovative things to specifically address our different student populations.” 

One example Professor Schmidt provides is phosphate kinases. While substitution chemistry is covered in detail in the old course, heavy emphasis is placed on halogens and tosylates, often neglecting nature’s favored leaving group, ATP-derived phosphates. In fact, there is an entire class of enzymes called kinases dedicated to the transfer of phosphate from ATP to a willing recipient like alcohols, creating the perfect leaving group for vital substitution reactions seen in the Citric Acid Cycle, glycolysis, and other metabolic pathways.

“[But phosphate kinases] are an incredibly huge class of enzymes in biochemistry we never explain [in the original series],” says Professor Schmidt. “We were never explaining that this is what nature does versus what synthetic chemists would do in a flask.”

By neglecting the biochemistry of enzymatic reactions in introductory organic chemistry sequences, biological science majors miss out on connections to cell processes. However, the renovated 40AB series seeks to rectify this discrepancy by supplementing biology-focused examples to the course, including closer examinations of specific enzymatic reactions and biological processes that serve as introductory organic mechanisms. 

“By learning these concepts of organic chemistry, we’re going to help you look at all those biological processes that you know and love through a molecular lens,” Professor Schmidt says. 

The ability to immediately connect organic chemistry concepts to biological examples has inspired new, invigorated interest in her 40AB students. “I’ve had so many students email me and say [the class] was so cool,” Professor Schmidt says with a laugh. “They’re like, I’ve heard about ATP and ADP over and over, but I’ve never understood why ATP is this energy currency, and now you’ve shown me what it looks like at the molecular level. It was really amazing to see light bulbs go off throughout the room. Like, yeah! Isn’t that awesome?”

Professor Klosterman notes something similar in 41ABC: “We brought back some stuff that had been cut away… like the Diers-Alder reaction. That’s really important in organic chemistry! Not so much in biology, which is why it was dropped out. But now you have time to cover how this reaction broke organic chemistry and made us finally accept molecular orbital theory as important.” He adds, “[Another example] is how some of the radical chemistry or the ideas of kinetics and thermodynamics were moved through quicker because we didn’t have time. Now you can slow down and dig into it a little bit more.”

He also identifies a benefit for organic chemistry professors. A single track for physical science majors means that both professors and students are able to accommodate one another. No longer will instructors need to guess which students have covered which topics under which professor. With a single condensed track of organic chemistry, professors can easily reference previous courses and check which topics students struggle with the most. They can then adjust their own courses to accommodate those gaps, facilitating a comprehensive mastery of organic chemistry. 

Perhaps most importantly, the dual organic chemistry series ensures that everyone who takes 41A will be funneled into 41B and 41C (and 40A into 40B). With the reassurance of familiar faces throughout the year, students are free to take the same section as their friends, form study groups, and attend industry events together, creating a web of students and faculty that all love and pursue chemistry—a much-needed step after the alienation of the COVID-19 pandemic.

Professor Schmidt comments, “I definitely see that sense of community even more amplified in the advanced upper division electives I’m teaching this quarter. We want to foster and celebrate that sense of community, because that’s actually how research is done. I was so happy to hear these students coming through the 41ABC series and how they felt like that’s been a benefit for them.”

Of course, all of these improvements don’t mean the work is complete. While students have mostly settled into the logistical side of the new series, the long-term effects of 40AB and 41ABC have yet to be seen.

Nonetheless, Professor Klosterman and Professor Schmidt remain optimistic. 

“We’ve developed a multi-year plan… and that includes assessment of how this is going,” Professor Schmidt says. “Is it working for our students? Is it working for our instructors? Are people still confused about it? What are the areas where we can continue to innovate and increase our original high-level goals?” 

She adds, “It’s not over yet. To me, this is not a past tense thing. We’re still in the active present tense of it all.”