This article presents the results of the study of explanatory models produced by 81 students of first-year of medicine at the Universidad del Norte in Barranquilla-Colombia. The students face a case in the area of chemistry applied to medicine, through a contextualized problem situation (SPC), constructed from a perspective of teaching chemistry in context. The explanatory models generated by the students were analyzed qualitatively at four moments of the implementation of a teaching proposal. The results obtained at the beginning of the implementation of the proposal indicate that the students did not elaborate any type of explanatory model. However, these arised from the teaching proposal that involves the SPC in which the students begin to generate explanatory models supported by chemistry content and categorized mostly in the research as Descriptive and Interpretative, a situation fostered by the theoretical and methodological coherence of the SPC, which was designed from a perspective of teaching in context based on modeling and leveraged by scaffolding.