The affordances given to a structured, timed, and proctored paper exam are not as readily applicable in a digital medium. Accordingly, the rapid shift from in-person to online enactments may have forced instructors to consider changing their assessment practices and priorities. As assessments convey strong implicit messages about “what counts” in a given learning environment, altering what is assessed may have a profound impact on what students view as important in a course. Our four-instructor team sought to examine whether we were able to maintain emphasis on assessing how and why chemical phenomena occur online while minimizing negative impacts to students, teaching assistants, and ourselves. To support claims regarding the degree to which online assessments emphasized sensemaking relative to past exams, we characterized all summative assessments given in organic chemistry II enactments from 2016 to the present using the three-dimensional learning assessment protocol. To examine the impact of enrolling in a rapidly assembled online organic course on student outcomes, we examined the distribution of students who performed above, at, or below the final exam score predicted by their midterm performance and compared this distribution with historic norms. Results suggest that we were able to maintain emphasis on student sensemaking as our course moved online (∼50% of points on exams administered remotely were dedicated to 3D performances). Additionally, the distribution of students enrolled this past spring who scored above, at, or below the final exam score predicted by their midterm performance was in line with historic norms. When taken in aggregate, our analyses suggest that organic chemistry-enrolled students maintained their ability to make sense of chemical phenomena after the pivot to online instruction. Consistent emphasis on assessing 3D learning online was achieved without adding appreciably to the burden on instructors or teaching assistants due to our assessment writing practices, streamlined approach to online grading, and pre-existing course resources. Instructional implications for assessment design, enacting team grading, and tracking student trajectories are provided in addition to a suite of assessment items with the potential to engage students in sensemaking.

Collagen is the most abundant protein in humans and the major component of human skin. Collagen mimetic peptides (CMPs) can anneal to damaged collagen in vitro and in vivo. A duplex of CMPs was envisioned as a macromolecular mimic for damaged collagen. The duplex was synthesized on a solid support from the amino groups of a lysine residue and by using olefin metathesis to link the N termini. The resulting cyclic peptide, which is a monomer in solution, binds to CMPs to form a triple helix. Among these, CMPs that are engineered to avoid the formation of homotrimers but preorganized to adopt the conformation of a collagen strand exhibit enhanced association. Thus, this cyclic peptide enables the assessment of CMPs for utility in annealing to damaged collagen. Such CMPs have potential use in the diagnosis and treatment of fibrotic diseases and wounds.

The self-assembly of collagen-mimetic peptides (CMPs) that form sticky-ended triple helices has allowed the production of surprisingly stable artificial collagen fibers and hydrogels. Assembly through sticky ends requires the recognition of a single strand by a templated strand dimer. Although CMPs and their triple helices have been studied extensively, the structure of a strand dimer is unknown. Here, we evaluate the physical characteristics of such dimers, using disulfidetemplated (PPG) 10 dimers as a model. Such "linked-dimers" retain their collagen-like structure even in the absence of a third strand, but only when their strands are capable of adopting a triplehelical fold. The intrinsic collagen-like structure of templated CMP pairs helps to explain the success of sticky-ended CMP association and changes the conception of new synthetic collagen designs.

A set of inexpensive and pedagogically rich experiments focusing on S N 1, E1, and E2 reactions have been updated to include modern computational and spectroscopic analyses. The S N 1 experiment involves treatment of tert-amyl alcohol with hydrochloric acid to generate the corresponding alkyl chloride, which is used as the starting material for the subsequent E2 reaction. The E1 experiment involves reaction of tert-amyl alcohol with sulfuric acid. Both elimination reactions generate a pair of isomeric methylbutenes, with the ratio being dependent on the reaction mechanism. The combination of computational chemistry and a recently developed fast heteronuclear single-quantum correlation spectroscopy method (ASAP-HSQC), in tandem with 1 H and 13 C NMR and GC−MS analysis, allows the E1 and E2 product mixtures to be fully analyzed by students.

Ultraviolet light causes skin cancer. Salicylic acid and other molecular filters absorb damaging radiation but are washed away readily. Conjugation to a collagen mimetic peptide is shown to retain salicylic acid on collagen-containing skin surrogates after repeated washing. This strategy, which is highly modular, could enhance the water-resistance of sunscreens.