NEET PG’s Favourite Lead Poisoning Question | 2 Enzymes You MUST Remember #biochemistry #neetpg

Added: 2026-05-21

[00:00:00]NEET PG frequently ask one enzyme blockage in lead poisoning, but most students forget one critical fact. Lead blocks two enzymes, not one.

[00:00:11]Plus, NEET PG loves case-based MCQs. So, in the next 60 seconds, you will learn the high-yield clinical clues that instantly help you crack a lead poisoning question.

[00:00:23]Heme synthesis happens partly in mitochondria, partly in cytoplasm.

[00:00:28]Lead blocks two key enzymes. First, ALA dehydratase, and second is ferrochelatase.

[00:00:37]ALA dehydratase blocked, so ALA accumulates in the blood and urine.

[00:00:44]That's your first diagnostic clue.

[00:00:47]Second, ferrochelatase blocked, iron can't insert into protoporphyrin.

[00:00:53]Protoporphyrin accumulates.

[00:00:56]Heme can't be formed, so microcytic hypochromic anemia occurs.

[00:01:02]That's the second clue. But, here's the NEET PG twist. Lead poisoning causes basophilic stippling of RBCs.

[00:01:10]Why? Because ribosomes aggregates when heme synthesis is disrupted.

[00:01:17]So, basophilic stippling will be your third clue.

[00:01:20]Symptoms to remember, lead lines on gums, wrist drop, foot drop, abdominal colic, and encephalopathy in kids. So, remember, lead blocks ALA dehydratase and ferrochelatase.

[00:01:36]ALA in blood and urine, microcytic hypochromic anemia, and basophilic stippling.

[00:01:44]Follow for more high-yield concepts that separates toppers from the rest.