As several contributors to this blog have pointed out, Joel Karty’s text introduces biochemistry topics early in the course through supplementary sections at the end of most chapters titled, “The Organic Chemistry of Biomolecules.” Many instructors have lauded this early inclusion of biomolecular topics as a motivator for biology majors and pre-professional students; one that facilitates understanding of subsequent and current coursework in biochemistry and biology. In addition, the modular nature of these sections provides significant flexibility for instructors, allowing us to decide what to teach and when to teach it.
During my year-long organic course for chemistry majors, I skipped over the biomolecule sections in the first quarter with plans to return with a single biochemistry unit in the spring quarter. Needless to say, it didn’t quite work out that way. The active learning emphasis of the course (see my previous post titled POGIL and Mechanisms are Natural Allies) slowed our progress, leaving us without adequate time for a biochemistry unit at the end. Instead, I decided to introduce beginning biochemistry topics through take home portions of hour exams. The biomolecular topics addressed in these assignments include chirality in biochemistry, pH and amino acids, and major classes of biomolecules. Since the reference sections of the Karty text were from early in the course, student’s anxiety is reduced toward the self-directed learning experience. Ultimately, with the strong foundation afforded by the course and the Karty text, the students had developed skills necessary to handle this material on their own.
By the time we approached later biochemical topics, such as aromaticity and DNA (14.12), and mutarotation of monosaccharides (18.14), it was apparent that there would not be enough time for a large biochemistry unit at the end of the course. Thus, these topics were fit into their respective chapters, or soon thereafter. For example, heterocyclic aromaticity can be a rather obscure topic without the application of DNA base pairing. Likewise, hemi-acetal formation seems rather pointless without discussing monosaccharide cyclization, and biomolecular polymers fit naturally in a discussion of polymers of all types (Ch26).
By incorporating biomolecular topics in multiple ways and formats, my students apply organic structure and principles in biomolecular systems, in a manner seamlessly supported by the Karty text. Skipping early biomolecule sections allows students to focus on the organic chemistry fundamentals at the beginning of the course. Later, self-directed learning provides an introduction to structure and acidity topics in biomolecules, while grabbing the interest of the students with a biochemistry concentration. The introductory nature of the early topics also provide both a review of fundamentals or organic chemistry, and a confidence boost for students. Further along in the course, biochemistry-oriented topics fit well with the organic content surrounding them, providing natural pathways linking organic chemistry and biomolecular subject matter, and therefore leaving my students with a more substantial understanding.
-Kimberley Cousins, California State University, San Bernardino