AP BIOLOGY

Detailed explanation-1: -Proline is an amino acid and belongs to the class which has hydrocarbon R-groups. “It does not contain the amino group-NH2 but is rather a secondary amine. The secondary amine nitrogen is in the protonated NH2+ form under biological conditions, while the carboxy group is in the deprotonated-COO-form.

Detailed explanation-2: -Glycine and proline residues are frequently found in turn and loop structures of proteins and are believed to play an important role during chain compaction early in folding. We investigated their effect on the dynamics of intrachain loop formation in various unstructured polypeptide chains.

Detailed explanation-3: -Proline confers an extended polypeptide structure and glycine is the only amino acid whose specific side group, -H, is so small that it forms no obstacle to hydrogen bonding between the peptide group and external molecules.

Detailed explanation-4: -Each of the 20 amino acids has a specific side chain, known as an R group, that is also attached to the carbon. The R groups have a variety of shapes, sizes, charges, and reactivities. This allows amino acids to be grouped according to the chemical properties of their side chains.