Question

Which enzyme catalyzes the insertion of iron into protoporphyrin IX during heme synthesis?

• A. Ferrochelatase
• B. ALA Synthase
• C. Porphobilinogen Deaminase
• D. Uroporphyrinogen Decarboxylase

Hint:

{Ferrochelatase} catalyzes the {final step of heme synthesis} by inserting Fe$^{2+}$ into protoporphyrin IX to form heme.

Answer 1

The Correct Option is A

Concept: Heme synthesis is a multi-step biochemical pathway that occurs partly in the mitochondria and partly in the cytoplasm of cells. Heme is an essential component of hemoglobin, myoglobin, and certain enzymes. The final step of heme synthesis involves the insertion of ferrous iron (Fe$^{2+}$) into protoporphyrin IX.
Step 1: Identify the enzyme responsible for inserting iron into protoporphyrin IX.

• Ferrochelatase – Catalyzes insertion of iron into protoporphyrin IX to form heme.
• ALA Synthase – Catalyzes the first step in heme synthesis.
• Porphobilinogen Deaminase – Involved in intermediate steps of porphyrin synthesis.
• Uroporphyrinogen Decarboxylase – Catalyzes conversion of uroporphyrinogen in the pathway.

Thus, the enzyme responsible for inserting iron into protoporphyrin IX is Ferrochelatase.