A binding site is a specific region on a molecule, such as a protein or enzyme, where another molecule, like a substrate or ligand, can attach. This interaction is crucial for various biological processes, including enzyme activity and signal transduction. The shape and chemical properties of the binding site determine which molecules can bind effectively. In the context of enzymes, the binding site is where the substrate binds to undergo a chemical reaction. The binding can lead to changes in the enzyme's structure, facilitating the conversion of substrates into products. Understanding binding sites is essential for drug design and developing therapies targeting specific proteins.