During the light-independent reaction of photosynthesis, CO2 is converted into organic substances, describe how.

The light-independent reaction (Calvin cycle) takes place in the absence of light. Firstly, CO2 combines with ribulose biphosphate (RuBP) to produce two molecules of glycerate-3-phosphate (GP). GP is reduced using reduced NADP and ATP from the light-dependent reaction to produce triose phosphate (TP). TP is converted into useful organic substances (eg. glucose) or into RuBP to renew the cycle.