Modelling Photosynthesis to Increase Conceptual Understanding

Biology students in their first year at university have difficulty understanding the abstract concepts of photosynthesis. The traditional didactic lecture followed by practical exercises that show various macroscopic aspects of photosynthesis often do not help the students visualise or understand the submicroscopic (molecular-level) reactions that are occurring within the chloroplast membranes. If students can construct their own complex concepts in small steps, with guidance from lecturers and demonstrators (teaching assistants) to ensure they are not building-in ‘new’ misconceptions, they are more likely to form positive attitudes towards further study and raise their self-esteem about learning strategies. This paper describes a teaching/re-teaching sequence of the light-dependent reactions of photosynthesis that presents the students with a range of learning and teaching approaches. Following a traditional didactic lecture, students have a practical exercise where they make their own models of chloroplasts, reinforced by small-group discussion sessions where they make their own diagram-matic summary. Online resources and textbooks are available for private study. The re-teaching step is an interactive lecture appealing to a range of learning modalities. Using this teaching and learning strategy, students increasingly use metacognitive skills to aid their further understanding of the submicroscopic world of atoms and molecules.