between Proteins and Nucleic Acids
Proteins are made up of a series of amino acids.

Nucleic Acids (RNA and DNA) are made up of a series of nucleotides.

The center of an amino acid is the carbon bonded to four different groups. The fourth group, R, is different for each amino acid.

A nucleotide is composed of a five-carbon sugar, a nitrogenous base and a phosphate group.

The five nitrogenous bases.