Glycine is highly conserved amino acid residue in the evolution of proteins. why?

Glycine is a highly conserved amino acid residue in the evolution of proteins. Why? Glycine has the smallest side chain of any amino acid. Its size often is critical in allowing polypeptide chains to make tight turns or to approach one another closely.

Explanation:

a polymer is a chainlike molecule made up of small molecular units. these small molecular units are called monomers. monomers of polymer can be joined together either naturally or synthetically.