Under physiological conditions, the immediate product of the reaction, the monodehydroascorbate radical, is reduced back to ascorbate by a monodehydroascorbate reductase (monodehydroascorbate reductase (NADH)) enzyme. In the absence of a reductase, two monodehydroascorbate radicals disproportionate rapidly to dehydroascorbic acid and ascorbate. APX is an integral component of the glutathione-ascorbate cycle.
Under physiological conditions, the initial product of the reaction, the monodehydroascorbate radical, gets reduced back to ascorbate by a monodehydroascorbate reductase enzyme (NADH). Without this reductase, two monodehydroascorbate radicals rapidly react to form dehydroascorbic acid and ascorbate. APX is an essential component of the glutathione-ascorbate cycle.