Calvin cycle forming a hexose

Question 1

why must the calvin cycle turn six times to form one hexose

Answer 1

Three turns of the cycle produces six molecules of triose phosphate because two molecules of TP are made for every one CO2 molecule used

five out of six of these TP molecules are used to regenerate ribulose biphosphate

this means that for three turns of the cycle only one TP is produced that’s used to make a hexose sugar

A hexose sugar has six carbons though, so two TP molecules are needed to form one hexose sugar

This means the cycle must turn six times to produce two molecules of TP that can be used to make one hexose sugar

six turns of the cycle need 18 ATP and 12 reduced NADP from the light-dependant reaction.