Concept Check (8.3)

A Trip around the Calvin Cycle

• The calvin cycle has inputs and outputs; the inputs are carbon dioxide from the air and ATP produced by the light reactions. The output is G3P molecules.

Steps of how the calvin cycle makes sugar:

1. Carbon dioxide enters while an enzyme adds each CO2 molecule with a RuBP molecule, forming six unstable six carbon molecules.
2. The three six carbon molecules break into six carbon molecules called 3-PGA.
3. ATP and NADPH provides evergy from light; molecules produced are used to convert the 3-PGA to G3P, which is a direct product of photosynthesis.
4. Carbon exits the cycle in one molecule of G3P, plants used these molecules to make glucose and other organic compounds.
5. Fifteen carbon atoms remain in 5 G3P molecules.
6. ATP provides energy that rearranges the G3P molecules.