LIFE SCIENCE

Detailed explanation-1: -Every amino acid also has another atom or group of atoms bonded to the alpha carbon known alternately as the R group, the variable group or the side-chain. Amino acids have a central asymmetric carbon to which an amino group, a carboxyl group, a hydrogen atom, and a side chain (R group) are attached.

Detailed explanation-2: -A peptide has two ends: the end with a free amino group is called the N-terminal amino acid residue.

Detailed explanation-3: -All the amino acids are found in -helices, but glycine and proline are uncommon, as they destabilize the -helix. Glycine is exempt from many steric constraints because it lacks a carbon.

Detailed explanation-4: -The bond between two amino acids is called peptide linkage.