NADPH+, H+ is generated in the reaction catalyzed by

uThe limited metabolic pathways present in red blood cells renders them completely reliant on the pentose phosphate pathway or, to be more specific, the X-linked enzyme glucose-6-phosphate dehydrogenase for the reduction of NADP+ to NADPH. uReduced NADPH is needed for the reduction of GSSG to GSH, a key intracellular antioxidant, by the enzyme glutathione reductase. uA deficiency in glucose-6-phosphate dehydrogenase renders red blood cells hypersensitive to oxidative stress. uIndividuals harboring G-6-PD deficiency are vulnerable to attacks of hemolytic anemia, resulting from the inability to generate sufficient reduced glutathione to combat episodes of oxidative stress. Harper's illustrated Biochemistry , 30th ed , page 693