Which among the following amino acid is heterocyclic in structure?
High-Yield Explanation
Histidine and tryptophan are heterocyclic amino acids. Phenylalanine and tyrosine are aromatic amino acids. Proline is an imino acid. Hydroxyproline, hydroxylysine, and ornithine are derived amino acids. Ref: Textbook of Biochemistry for Medical Students By Dm Vasudevan, 2010, Page 20.