1. Rubisco adds carbon onto your carbon chain. 2. The 6 carbon chain is unstable and breaks apart. 3. NADPH donates electrons, which can't be seen in the model, to the 3 carbon molecule.
4. The 5 carbon molecule is regenerated. one 3 carbon molecule exits to the cytoplasm. It will combine with another one to make sugar.
5. ATP donates a phosphate group to the 3 carbon molecules.