Answer:
The statement is referring to the active site of an enzyme. The active site is a specific region on the surface of an enzyme where substrates (reactant molecules) bind to undergo a chemical reaction. The active site is typically a pocket or groove that is uniquely shaped to fit the specific substrate(s) with which the enzyme interacts. When the substrate(s) bind to the active site, they are held in a precise orientation that promotes the chemical reaction to occur, ultimately resulting in the formation of a product.