Rubisco

Edexcel A-level BiologyPhotosynthesisLesson 15 of 20

RUBISCO (ribulose bisphosphate carboxylase-oxygenase) is the enzyme in the stroma that fixes carbon dioxide in the Calvin cycle. It catalyses the reaction between CO₂ and RuBP to form two molecules of GP. Almost all the carbon in living things has passed through this reaction.

RUBISCO is thought to be the most abundant protein on Earth. There is so much of it because it is a very slow enzyme: each molecule fixes only a few CO₂ molecules per second, compared with thousands of reactions per second for many enzymes. To fix enough carbon, leaves contain large amounts of it, up to about half of their soluble protein.

More in Photosynthesis

• The Light-Independent Stage
• The Calvin Cycle
• The Products of Photosynthesis
• C4 Plants
• Limiting Factors of Photosynthesis
• Light
• Carbon Dioxide
• Temperature

All 20 lessons in Photosynthesis · All Edexcel A-level Biology topics