Composed of two seemingly disparate parts, this dissertation ultimately seeks to extend our understanding of biochemistry. The first part investigates a glycosyltransferase enzyme in the O-mannosylation pathway responsible for glycosylating the cell surface glycoprotein, α-dystroglycan. α-Dystroglycan is extensively modified with O-mannose glycans that are critical to basement membrane assembly via interactions with laminin and other proteins. Disruption of the O-mannosylation pathway involved in functional glycosylation of α-dystroglycan gives rise to congenital muscular dystrophies. With recent advancements, the entire functional glycan structure on α-dystroglycan and the enzymes responsible for its biosynthesis are known. POMGNT2 catalyzes the first step toward the functional glycan structure on α-dystroglycan. Yet, how specificity at each step in the biosynthesis of the elaborate glycan structure is achieved remains unknown. Studies undertaken in the first part of this dissertation aim to elucidate the substrate selectivity of POMGNT2 for two sites on α-dystroglycan. In vitro, POMGNT2 displays significant primary amino acid selectivity near the site of O-mannosylation. Further studies show that addition of primary amino acid determinants for POMGNT2 activity can lead to functional glycosylation elsewhere on α-dystroglycan. The second part of this dissertation investigates undergraduate student thinking and targeted instruction about noncovalent interactions. Noncovalent interactions represent a core concept in undergraduate biochemistry courses. Yet, how undergraduate biochemistry students build conceptual understanding and problem-solving skill pertaining to noncovalent interactions remains largely unknown. In light of rejuvenated effort to improve undergraduate biochemistry education, the studies undertaken in the second part of this dissertation aim to characterize student thinking about noncovalent interactions in order to develop targeted instruction for this concept. Interviews with experts and students as they solved a protein structure-function problem revealed several student difficulties including challenges with explaining electrostatic principles of noncovalent interactions. Using the identified student difficulties, various types of targeted instruction deriving from distinct conceptual frameworks were developed and compared. This study suggests more than unscaffolded guidance is necessary for successful near transfer of knowledge about noncovalent interactions. Together, this body of work is an interdisciplinary research effort comprising both glycobiology and discipline-based education research in biochemistry.