The process of identifying threshold concepts invites experts to reflect on their discipline in a new way with the ultimate goal of improving learning and teaching. During a workshop to identify threshold concepts in biochemistry, we asked a group of natural scientists to explore "signification," a threshold concept from the humanities, as a mechanism to push them out of their comfort zones and recall how it feels to experience learning from a student's perspective. In addition to accomplishing this goal, we subsequently realized that signification could also help us uncover and remedy ways in which use of scientific terminology impedes learning in biochemistry. Using the results of a survey of university teachers that aimed at refining a list of possible threshold concepts, we present three scenarios to illustrate the challenges that teachers and students encounter when attempting to cement a label (the "signifier) and a concept (the "signified") into a coherent sign. Based on these findings, we propose that teachers can better explore threshold concepts if they carefully consider the role terminology plays in learning and teaching. Thus we describe the "terminological canyon" through which university teachers must journey in order to produce effective learning and teaching activities related to the threshold concepts. While the work described here pertains to biochemistry, we believe the process and findings can be generalized to a broad range of disciplines.