EVERYDAY SCIENCE

Detailed explanation-1: -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. Refer to the charts and structures below to explore amino acid properties, types, applications, and availability.

Detailed explanation-2: -The side chain is different for each amino acid. At a physiologic pH of 7.4, the amino group on these amino acids carries a positive charge and the carboxylic acid group is negatively charged (see Fig. 6.1B).

Detailed explanation-3: -Proteins are chains of amino acids that assemble via amide bonds known as peptide linkages. The difference in the side-chain group or R-group is what determines the unique properties of each amino acid.

Detailed explanation-4: -As we mentioned earlier, the side chains in a polypeptide chain determine how it folds into a three-dimensional structure. This occurs in part because the amino acid side chains differ in their size and flexibility, which in turn biases the peptide backbone toward certain conformations.

Detailed explanation-5: -There are three amino acids that have basic side chains at neutral pH. These are arginine (Arg), lysine (Lys), and histidine (His). Their side chains contain nitrogen and resemble ammonia, which is a base.