What is the importance of the –R group (variable radical) in an amino acid molecule?
The –R group, also called a lateral chain, is the variable part of the amino acid molecule. The –R group can be a complex carbonic chain, a substituting methyl group (forming then the amino acid alanine) or even only a hydrogen (forming glycine, the simplest amino acid). So the –R group is important because it is the differentiation factor of amino acids