Amino acids: practice question

The best answer is D, Arginine. Nitric oxide synthase converts arginine to nitric oxide and citrulline; endothelial nitric oxide then promotes vascular smooth-muscle relaxation.

Histidine is converted to histamine.

Methionine is important for methyl-group donation.

Tryptophan is a precursor of serotonin.

It tests Amino acids in Biochemistry. The correct option holds because: Correct: nitric oxide synthase uses arginine as substrate.

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.

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.

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.