Biopolymer

Biopolymers, sometimes referred to as biological macromolecules, are polymers of biological importance such as proteins, nucleic acids, and carbohydrates. Like all polymers, biopolymers are formed by joining together many copies of repeating units to form long chains that have a repeating or constant backbone and variable side chains. The repeating units of proteins are the 20 naturally occurring amino acids that form a polypeptide chain. Nucleic acids are formed from nucleotides and have a sugar-phosphate backbone with purine or pyrimidine side chains.

References

A. G. Walton and J. Blackwell (1973) Biopolymers, Academic Press, New York. 

P. Munk (1989) Introduction to Macromolecular Science, Wiley-Interscience, New York.