Pentone phosphate pathway


Site: Cytoplasm of all actively dividing cells

Rate limiting enzyme: Glucose-6-phosphate dehydrogenase (G6PD)

Oxidative phase:

  • Substrate: Glucose 6 phosphate
  • NADP is required.

Non-oxidative phase:

  • 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.

Clinical correlation:

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:

  1. Glutathione peroxidase
  2. Glutathione reductase
  3. Superoxide dismutase
  4. Myeloperoxidase.


Heinz body:

  • Hemoglobin inside RBC gets oxidized by reactive oxygen species
  • Seen in G6PD deficiency anemia.

How useful was this post?

Click on a star to rate it!

Average rating 4.8 / 5. Vote count: 5

No votes so far! Be the first to rate this post.

Leave a Reply

Your email address will not be published.