The quality of the process of teaching is related to the behaviors shown by the teacher and their capability. In cases where teachers who have different training are expected to teach the same topic, teachers may make some alterations in the topics in question. Turkish education system has teachers who have different training but teach the same subject. Transposition is an institutional framework which is concerned with transformation of the knowledge given in schools from its status as didactic scientific knowledge to learned knowledge. The purpose in this study is to determine the factors influential on the process of transformation from knowledge to be taught to knowledge that is taught that are caused by science teachers. In this context, this study was conducted with 5 science teachers with different training and a total of 159 students of these teachers at 7th grade. Interviews were held with the science teachers and students on the subjects of electron configuration and chemical properties and chemical bonds, and their classes were recorded. As a result of the collected data, it was concluded that the science teachers with different training take the curricula into consideration while transforming the knowledge to be taught, and this transformation was affected by the department they graduated from.