Summary
The enzyme that fixes carbon dioxide in the Calvin cycle and is likely the most abundant protein on Earth.
In depth
It is slow (3 to 10 reactions per second) and makes mistakes by binding O2. Plants make large amounts to compensate, making up about 50 percent of leaf protein. It is a target for improving crop yields.
Rubisco's slow rate and confusion with oxygen suggest that it evolved when oxygen was scarce. Plants compensate by making lots of it, and by concentrating CO2 in C4 and CAM plants.
Remember: rubisco is in the stroma and is made of large and small subunits.
Frequently asked questions
What is Rubisco?
The enzyme that fixes carbon dioxide in the Calvin cycle and is likely the most abundant protein on Earth.
Which area of biology covers Rubisco, and how advanced is it?
Rubisco is one of the 56 topics in Plant Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Calvin Cycle, Photorespiration, Photosynthesis.
Can you give an example of Rubisco?
The enzyme is estimated to be the most abundant on Earth.
What should I learn before Rubisco?
Work through the Beginner topics in Plant Biology first, such as Plant Kingdom, Photosynthesis, Chlorophyll, then return to Rubisco. Intermediate topics assume the Beginner vocabulary.
What topics are related to Rubisco?
The closest topics to Rubisco are Calvin Cycle, Photorespiration, Photosynthesis, Photosynthesis Efficiency Engineering. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Rubisco?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Rubisco. To practise the whole of Plant Biology, use the Plant Biology quiz.
How is Rubisco different from Calvin Cycle?
Rubisco: The enzyme that fixes carbon dioxide in the Calvin cycle and is likely the most abundant protein on Earth. Calvin Cycle: Light-independent reactions in the stroma that use ATP and NADPH to fix carbon dioxide into sugar. Read both side by side and note what each one explains.
How should I study Rubisco step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Calvin Cycle and explain the difference aloud. Finally, take the Plant Biology quiz and come back to this page for any question you miss.