Multiple choice Choose the incorrect reaction. Ribulose-1,5-bisphosphate → 3-phosphoglycerate: Rubisco 3-Phosphoglycerate → Glycerate-1,3-bisphosphate: Phosphoglycerate kinase Dihydroxy acetone phosphate → Fructose 1,6-bisphosphate: Aldolase Xylulose 5-phosphate → Ribulose 5-phosphate: ribose-5-phosphate isomerase Ribulose 5-phosphate → Ribulose-1,5-bisphosphate: Phosphoribulokinase ribose 5-phosphate isomerise Reveal answer Fill a bubble to check yourself D Correct answer Explanation Conversion of xylulose 5-phosphate to ribulose 5-phosphate is catalysed by ribulose-phosphate epimerase. Conversion of ribose 5-phosphate to ribulose 5-phosphate is catalysed by ribose 5-phosphate isomerise.