NANP Board Practice Exam

Which amino acid is the end product of sulfur metabolism in mammals?

1. Alanine

2. Glycine

3. Taurine

4. Valine

The correct answer is: Alanine

The correct answer is taurine, as it is indeed the end product of sulfur metabolism in mammals. In the body, sulfur-containing amino acids like cysteine and methionine undergo transformation, and taurine is formed through a series of biochemical reactions involving these amino acids. Taurine plays critical roles in various physiological functions, including bile salt formation, osmoregulation, and cardiovascular health, demonstrating the significance of sulfur metabolism in overall well-being. Regarding the other choices: alanine, glycine, and valine are non-sulfur-containing amino acids that do not represent the final product of sulfur metabolism. Alanine and glycine are more associated with energy metabolism and gluconeogenesis, whereas valine is a branched-chain amino acid involved in muscle metabolism and energy production but unrelated to the sulfur metabolic pathway.