Enzymes and Their Role in the Body

Enzymes are proteins that help chemical reactions happen in the body. Without enzymes,

reactions would happen very slowly, meaning food could not be broken down and nutrients would

not enter the bloodstream. Each enzyme has an active site, which is the area where the substrate

binds. The substrate is the molecule the enzyme acts on. The enzyme and substrate

must match in shape, like a lock and key. After the reaction, the substrate is

changed into products, while the enzyme stays the same and can be reused. Enzymes help with

two types of reactions. Digestion reactions break large molecules into smaller ones. Synthesis reactions

build small molecules into larger ones. Enzymes are named after their substrates and end in -ase.