Oxidative phase

Glucose 6-phosphate + NADP⁺ → 6-phosphoglucono-δ-lactone + NADPH + H⁺

Glucose 6-phosphate dehydrogenase

6-Phosphoglucono-δ-lactone + H₂O → 6-phosphogluconate + H⁺

Lactonase

6-Phosphogluconate + NADP⁺ → ribulose 5-phosphate + CO₂ + NADPH + H⁺

6-Phosphogluconate dehydrogenase

Nonoxidative Phase

Ribulose 5-phosphate ⇋ ribose 5-phosphate

Phosphopentose isomerase

Ribulose 5-phosphate ⇋ xylulose 5-phosphate

Phosphopentose epimerase

Xylulose 5-phosphate + ribose 5-phosphate ⇋

        Transketolase sedoheptulose 7-phosphate + glyceraldehyde 3-phosphate

Transketolase

Sedoheptulose 7-phosphate + glyceraldehyde 3-phosphate ⇋

                            Transaldolase fructose 6-phosphate + erythrose 4-phosphate

Transaldolase

Xylulose 5-phosphate + erythrose 4-phosphate ⇋

                   Transketolase fructose 6-phosphate + glyceraldehyde 3-phosphate

Transketolase