Instructors draw on their intentions for student learning in the enactment of curriculum, particularly in the selection and presentation of external representation of scientific phenomena. These representations both create opportunities for students to experience non-experiential biochemical phenomena, such as protein translation, and constrain the possibilities for student learning based on the limited number of features depicted and the visual cues used to draw viewers attention to those features. In this study, we explore biochemistry instructors' intentions for student learning about protein translation and how those intentions influence their selection of external representations for instruction. A series of instructor interviews were used to identify information that students need to know in order to develop a biochemically accurate understanding of protein translation. We refer to this information as the "critical features" of protein translation. Two dominant themes of critical features were identified: (1) components/structures of protein translation and (2) interactions/chemistry of protein translation. Three general components (the ribosome, the mRNA, and the tRNA) and two primary interactions (base pairing and peptide bond formation) were described by all instructors. Instructors tended to favor simpler, stylized representations that closely aligned with their stated critical features of translation for instructional purposes.