Final answer:
A decomposition reaction is where a large molecule breaks into two smaller ones, often through a process like hydrolysis.
Step-by-step explanation:
The term that best describes a reaction where a large molecule breaks into two smaller ones is a decomposition reaction. This type of reaction involves the breaking of one or more bonds within a larger molecule, releasing smaller molecules or atoms. It contrasts with anabolic reactions, which build larger molecules from smaller ones.
A decomposition reaction can often be represented as follows:
A large molecule → smaller molecule + another smaller molecule
One specific example of a decomposition reaction is hydrolysis, where water is used to break down polymers into monomers.