Integrating hands‐on model building with graded online discussions to learn DNA structure‐function relationships in an upper level General Biochemistry course for majors

Abstract

An active‐learning DNA structure/function exercise was undertaken in a 4000‐level majors biochemistry course. During the fourth in‐person class period of the spring 2020 semester majors enrolled in a three‐credit General Biochemistry course were asked to build a physical model of DNA consisting of one turn of the helix including 10 base‐pairs. Students were told to self‐associate into groups of six and each group was then instructed to build a specific base‐pair: 5 groups were assigned GC, 5 were assigned AT. Students were further instructed to divide the labor by partnerships, one to build a purine base, another to build the complementary pyrimidine, and the third to build the sugar‐phosphate. The class was provided with large bundles of six different brightly colored pipe‐cleaners, a bamboo skewer to use as an in‐plane scaffold for the base‐pairs, a large ring stand, and 10 perpendicular rod clamps. They were then given 10 minutes to build their respective base‐pairs then the last five minutes to work together as a class to assemble a single model. The instructor and many students photographed the model and uploaded image files to the online learning platform accompanied by the following prompt.“How much information can we obtain from the admittedly incomplete model we built in class today? Examine the photograph and see if you can decipher the sequence on the two strands. We know adenine is yellow, thymine is purple, guanine is orange, and cytosine is blue. If this sequence were part of a gene which amino acids might they encode? What information would help us answer these questions more precisely? Feel free to share any photos you took during class in replies to this post. You may opt‐out of any one of the next three weekly graded discussions by building your own improved, more beautiful model using the same starting materials for equal credit.”This exercise incorporates multiple active‐learning techniques simultaneously including elements of “think‐pair‐share” during the initial partnership phase, small group work during the assembly of the mononucleotides, and large group cooperation during final assembly of the model. The online follow‐up discussion and optional model‐refinement assignment allow individualized student‐driven engagement with the structure of DNA and how it works to store genetic information.Support or Funding InformationDepartment of Biochemistry College of Agriculture and Life Sciences at Virginia Polytechnic and State University (Virginia Tech)A single turn of the DNA double‐helix: a physical model cooperatively created by students in a 4000 level General Biochemistry course as part of an active‐learning exercise. Model built with large ring stand, 10 perpendicular rod clamps, brighlty‐colored pipe‐cleaners, bamboo skewers, and small plastic beads.Figure 1