Chemistry - Biomolecules Question with Solution | TestHub

Methionine is the only amino acid among the given options that contains sulphur.

During sodium fusion, an organic compound containing both nitrogen and sulphur forms sodium thiocyanate ($NaSCN$).

This extract gives a blood-red colour when treated with $F{e}^{3+}$ ions due to the formation of ferric thiocyanate, $[Fe(SCN){]}^{2+}$.

Although the question mentions sodium nitroprusside (which typically yields a violet colour with sulphide ions), the blood-red colour specifically confirms the presence of both nitrogen and sulphur. Therefore, methionine is the correct choice.

Answer: methionine