Amino acid metabolism: practice question

A Biochemistry question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Biochemistry · Amino acid metabolism

Sample item

What amino acid is the precursor of histamine?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. Histidine

Histamine is produced by decarboxylation of histidine and acts in allergy, gastric acid secretion, and several neurotransmitter pathways.

Option by option

  • A. Tryptophan

    Tryptophan is a precursor of serotonin and niacin.

  • B. Histidine (correct)

    Correct: histidine is decarboxylated to histamine.

  • C. Tyrosine

    Tyrosine is a precursor of catecholamines and melanin.

  • D. Methionine

    Methionine provides methyl groups through S-adenosylmethionine.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More Biochemistry questions

Questions about this Biochemistry question

What is the answer to this Biochemistry question?

The best answer is B, Histidine. Histamine is produced by decarboxylation of histidine and acts in allergy, gastric acid secretion, and several neurotransmitter pathways.

Why is "Tryptophan" not the answer?

Tryptophan is a precursor of serotonin and niacin.

Why is "Tyrosine" not the answer?

Tyrosine is a precursor of catecholamines and melanin.

Why is "Methionine" not the answer?

Methionine provides methyl groups through S-adenosylmethionine.

What concept does this question test?

It tests Amino acid metabolism in Biochemistry. The correct option holds because: Correct: histidine is decarboxylated to histamine.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Amino acid metabolism?

Build one table of enzyme deficiency, disease, inheritance and key finding, then revise it by spaced recall. Then use the flashcards and the other Biochemistry questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.