biopolymer noun1 •Any macromolecule of a living organism that is formed from the polymerization of smaller entities; a polymer that occurs in a living organism or results from life.There are three main classes of biopolymers: polynucleotides (such as RNA and DNA), polypeptides (such as collagen and actin), and polysaccharides (such as cellulose and starch). formsbiopolymers