The structural formulas for the 20 naturally occurring amino acid residues are shown in the panel below. Answer the following question(s) with the help of this panel.

-Which of the amino acids shown above has the most limited combinations of phi (?) and psi (?) angles in its Ramachandran plot? Write down the one-letter abbreviation for it, e.g. A.

Question

The structural formulas for the 20 naturally occurring amino acid residues are shown in the panel below. Answer the following question(s) with the help of this panel.
 
-Which of the amino acids shown above has the most limited combinations of phi (?) and psi (?) angles in its Ramachandran plot? Write down the one-letter abbreviation for it, e.g. A.

Quizplus · Accepted Answer

Proline, being an imino acid, can adopt only a limited set of configurations within a polypeptide chain.

The Structural Formulas for the 20 Naturally Occurring Amino Acid