Glycolytic Reversal

The reduction step, described in the textbook as 'glycolytic reversal', converts each molecule of 3-PGA into 1,3-diphosphoglyceric acid, using up a molecule of ATP; this intermediate is then reduced, using NADPH2 supplied by the light reaction, to glyceraldehyde-3-phosphate (3-PGAL). Keeping this cycle running continuously therefore depends on a steady supply of both ATP and NADPH2 from the light …