What reaction breaks the bonds between the subunits in a polymer chain?

The reaction that breaks the bonds between the subunits in a polymer chain is a hydrolysis reaction. Hydrolysis involves the addition of water to a polymer, resulting in the cleavage of covalent bonds that hold the subunits, or monomers, together. This process effectively breaks the polymer into smaller units, often reviving the individual monomers.

In biological systems, hydrolysis is essential for the digestion of larger biomolecules, such as polysaccharides, proteins, and nucleic acids. For example, when you consume starch, the polymer is hydrolyzed into glucose units through the action of enzymes and water during digestion.

In contrast, condensation reactions involve the removal of water to form bonds, reducing the number of monomers in a polymer chain. Reduction and oxidation reactions relate to changes in electron states and do not pertain to the breaking of polymer chains in this context. Thus, hydrolysis specifically describes the reaction that breaks down polymers into their constituent subunits by adding water.