Site: Cytoplasm of all actively dividing cells
Rate limiting enzyme: Glucose-6-phosphate dehydrogenase (G6PD)
- Substrate: Glucose 6 phosphate
- NADP is required.
- Substrate: Fructose 6 phosphate
- NADP is not required.
End product: Pentose sugar
Energy: No ATP required, no ATP produced
Then why pentose phosphate pathway is required for our body?
To produce free NADPH, which maintains Glutahione in a active (reduced) state. Active Glutathione protects our body from harmful free radicals.
G6PD deficiency → Deficiency of NADPH → Glutathione remains in its inactive (oxidized) state → Free radicals accumulate inside RBC → Destruction of RBC → Hemolytic anemia.
Hemolysis in G6PD deficiency is due to reduced activity of:
- Glutathione peroxidase
- Glutathione reductase
- Superoxide dismutase
- Hemoglobin inside RBC gets oxidized by reactive oxygen species
- Seen in G6PD deficiency anemia.