Which of the following -amino acids contains a secondary amine group in its core structure, chemical — Biomolecules Chemistry Question

💡 Solution & Explanation

Proline's side chain seamlessly connects back to the $\alpha$ -amino nitrogen, forming a rigid five-membered pyrrolidine ring. Because the nitrogen is bonded to two carbon atoms, it is a secondary amine (imino acid), significantly influencing protein folding (often causing kinks in $\alpha$ -helices).