Final answer:
The association affinity between two macromolecules is determined by the number and type of non-covalent bonds that form between them.
Step-by-step explanation:
The affinity of association between two macromolecules is dictated by the number and type of non-covalent bonds between them. While monomers link by covalent bonds to form polymers, the interaction between different macromolecules or different parts of a single macromolecule often involves non-covalent bonds. These non-covalent interactions include hydrogen bonds, ionic bonds, van der Waals forces, and hydrophobic interactions, which all dictate how effectively macromolecules associate with one another.