Ferrochelatase is inhibited by -: (A) Arsenic, (B) Lead, (C) Chromium, (D) Mercury
Answer is B. Ans. is 'b' i.e., Lead * Lead inhibits ALA dehydratase. Therefore, lead poisoning causes inhibition of heme synthesis and excessive amount of d-ALA is excreted in urine. Lead can also inhibit ferrochelatase (heme synthase).