This research investigates various purposes of teacher discourse moves essential to orchestrate dialogic discourse in secondary science classrooms. Data collected includes classroom observations and teacher interviews of two teachers teaching in an Indian school setting, whose classroom practices subscribed to a dialogic framework. A discursive move framework was developed, using a grounded, interpretative approach, to analyse teacher moves and their purposes at the utterance level. Iterative examination of the data led to the emergence of overarching goals being pursued for dialogic organisation of talk. These goals are conceptualised as three components of a schema characterising dialogic discourse in science classrooms: Foundation (F) aimed at developing a culture of discourse; Initiation (I) moves working towards sparking students' multiple perspectives; and Perpetuation (P) moves, which engage students in active exchange of ideas. Through axial coding, it emerged that teacher utterances, as detailed in the discursive framework, enabled the three components to come into play in dialogic classrooms. Specific tools used by the two teachers have been identified. A repertoire of tools facilitating teachers to position themselves as 'enablers of talk for thinking' [Chin, C. (2006). Classroom interaction in science: teacher questioning and feedback to students' responses. "International Journal of Science Education," 28(11), 1315-1346.] has been identified.