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Biochemistry · Amino acids
Sample itemWhich amino acid is precursor of catecholamines?
Original practice item, not a recalled exam question. Nothing here is recorded.
The answer and the reasoning
A. Tyrosine
This item reviews Amino acids; Tyrosine is the best answer because it directly matches the biochemical or pathological mechanism described.
Option by option
A. Tyrosine (correct)
Correct. Tyrosine fits the defining mechanism.
B. Methionine
Methionine is unsupported by the key feature.
C. Tryptophan
Tryptophan does not fit the stated pattern.
D. Histidine
Histidine is plausible but not the best answer.
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.