The activities designed by 91 teams of primary teacher education students as part of their teaching proposals in a course on science teaching are analysed together with the subsequent reformulations of those activities. The objective of the study was to gain insight into the students' professional practical knowledge and the underlying focus of their approach to teaching. Qualitative methods based on content analysis were applied. The instruments used were a reflection script and the students' teaching proposals about the different versions of a specific theme of science content. The results indicate that these prospective teachers' knowledge about the types of activities that are appropriate for teaching science changed during the course from a teacher- and teaching-centred approach centred to one focused on the pupil and learning. The implications for science teacher education are discussed.