A polymer is a widely occurring chemical structure in nature and technology consisting of a chain of similar subunits (called monomers) linked together into a chain. Typically, the polymer backbone contains large quantities of carbon atoms, which is part of the reason why organic chemistry (the study of carbon-based chemical structures) is so important.

Nylon and silicone are two common synthetic polymers, but we are interested in polymers produced by living organisms, called biopolymers. Biopolymers constitute nucleic acids, proteins, carbohydrates, and lipids. Specifically, we will focus on nucleic acids and proteins, whose monomers are nucleotides and amino acids, respectively.

Nucleic acid chains that are 50 nt or shorter are usually called "oligonucleotides," and short polymers of amino acids are referred to as "peptides."

In the figure below, we show a variety of possible polymer structures; biopolymers are usually linear in structure.