Summary
Light-independent reactions in the stroma that use ATP and NADPH to fix carbon dioxide into sugar.
In depth
Carbon fixation: rubisco joins CO2 to RuBP, forming two 3-phosphoglycerate; reduction using ATP and NADPH makes G3P; regeneration of RuBP uses ATP. Three turns give one G3P net; sugars, starch and other compounds are made from G3P.
The cycle runs in the light because it depends on ATP and NADPH, and light also activates enzymes via ferredoxin-thioredoxin. Six turns fix six CO2 to make one glucose equivalent, using 18 ATP and 12 NADPH.
Example: the 3-carbon sugar G3P can be exported to make sucrose or kept to make starch.
Frequently asked questions
What is Calvin Cycle?
Light-independent reactions in the stroma that use ATP and NADPH to fix carbon dioxide into sugar.
Which area of biology covers Calvin Cycle, and how advanced is it?
Calvin Cycle 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 Photosynthesis, Rubisco, Light-Dependent Reactions.
Can you give an example of Calvin Cycle?
Radioactive 14C labelling by Calvin mapped the pathway.
What should I learn before Calvin Cycle?
Work through the Beginner topics in Plant Biology first, such as Plant Kingdom, Photosynthesis, Chlorophyll, then return to Calvin Cycle. Intermediate topics assume the Beginner vocabulary.
What topics are related to Calvin Cycle?
The closest topics to Calvin Cycle are Photosynthesis, Rubisco, Light-Dependent Reactions, C4 Photosynthesis. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Calvin Cycle?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Calvin Cycle. To practise the whole of Plant Biology, use the Plant Biology quiz.
How is Calvin Cycle different from Photosynthesis?
Calvin Cycle: Light-independent reactions in the stroma that use ATP and NADPH to fix carbon dioxide into sugar. Photosynthesis: Plants use light, water and carbon dioxide to make glucose and oxygen. Read both side by side and note what each one explains.
How should I study Calvin Cycle 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 Photosynthesis and explain the difference aloud. Finally, take the Plant Biology quiz and come back to this page for any question you miss.