the differences between amino acids are in the?

A: side groups
B: hydrogen atoms

The differences between amino acids are primarily in the side groups. Each amino acid has a central carbon atom called the alpha carbon, which is bonded to four groups: an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom, and a side group or side chain, denoted as R. It is the variation in the side group or R-group that distinguishes one amino acid from another. The side groups can differ in size, shape, charge, polarity, and functional groups, leading to different chemical properties and roles in protein structure and function.

On the other hand, hydrogen atoms are found in every amino acid but do not contribute to the differentiation between amino acids. Hydrogen atoms are the simplest element, consisting of one proton and one electron. While they play important roles in the overall structure and function of amino acids, they are not responsible for the variations and unique characteristics observed between different types of amino acids.