NURSING ANM AND GNM

Detailed explanation-1: -Proline is unique among the standard amino acids in that it does not have both free -amino and free -carboxyl groups. Instead, its side chain forms a cyclic structure as the nitrogen atom of proline is linked to two carbon atoms.

Detailed explanation-2: -The carbon, carboxyl, and amino groups are common to all amino acids, so the R-group is the only unique feature in each amino acid.

Detailed explanation-3: -Amino acids differ from each other with respect to their side chains, which are referred to as R groups. The R group for each of the amino acids will differ in structure, electrical charge, and polarity.