C4 and CAM Photosynthesis

Abstract

This guided inquiry activity introduces undergraduate biology students to the carbon-concentrating mechanisms in C₄ and CAM plants. Designed for a classroom setting using a POGIL format, the activity supports learning through the three-phase learning cycle. Students work collaboratively to analyze models representing photorespiration in C₃ plants and compare it with the biochemical and anatomical adaptations found in C₄ and CAM pathways. Emphasis is placed on how these adaptations reduce photorespiration and improve photosynthetic efficiency in hot and dry environments. The activity aligns with upper-level plant physiology or general biology courses and develops key process skills such as teamwork and information processing. Learning objectives include describing carbon-concentrating mechanisms, explaining how they reduce photorespiration, and comparing structural and functional differences between photosynthetic strategies.
Level: Undergraduate | Setting: Classroom | Activity Type: POGIL Learning Cycle
Discipline: Biology | Course: Plant Physiology, General Biology
Keywords: C₄ photosynthesis, CAM photosynthesis, photorespiration, Rubisco, carbon concentrating