What is the difference between the structure of DNA and proteins? The monomers that compose DNA are nucleotides and the monomers that compose proteins are amino acids the monomers that compose DNA are ammo acids and the monomers that compose proteins are nucleotides. They are composed of the same monomers but only differ in their 3-dimensional structure. They are composed of the same monomers but only differ in the primary structure. Solution The monomers that compose DNA(deoxyribo nucleic acid) are nucleotides and the monomers that compose proteins are amino acids. Nucleotides are organic molecules (building blocks) of DNA and composed of a nitrogenous base, a five-carbon sugar(ribose or deoxyribose), and at least one phosphate group..