trifunctional aldehyde reductase/xylose reductase/glucose 1-dehydrogenase (NADP(+)
D-Xylitol + NAD → D-Xylulose + Hydrogen Ion + NADH
D-Xylose + NADP → D-Xylitol + Hydrogen Ion + NADPH
Adenosine triphosphate + D-Xylulose → Adenosine diphosphate + Hydrogen Ion + Xylulose 5-phosphate
D-Ribulose 5-phosphate → D-Ribose 5-phosphate
Xylulose 5-phosphate → D-Ribulose 5-phosphate
D-Erythrose 4-phosphate + Xylulose 5-phosphate → D-Glyceraldehyde 3-phosphate + β-D-fructofuranose 6-phosphate
D-Glyceraldehyde 3-phosphate + D-Sedoheptulose 7-phosphate → D-Erythrose 4-phosphate + β-D-fructofuranose 6-phosphate
D-Ribose 5-phosphate + Xylulose 5-phosphate → D-Glyceraldehyde 3-phosphate + D-Sedoheptulose 7-phosphate