Answer;
-Proteins can contain a variety of R groups
Step-by-step explanation;
-All amino acids have the alpha carbon bonded to a hydrogen atom, carboxyl group, and amino group. The R group varies among amino acids and determines the differences between these protein monomers.
Hydrogen bonds in secondary structure involve the polar amino and carboxyl groups of amino acids, but do not involve R-groups.As the peptide chain continues to grow, interactions between amino acid side chains (R-groups) form the tertiary structure of a polypeptide.