Answer: Enzymes
Enzymes are special proteins which catalyze the reaction within the body. Catalyzing action of enzymes indicates that they complete the reaction before it's usual rate hence, they speed up the chemical reaction. They can make a chemical reaction millions of times faster than it would be without enzyme. The substrate binds to the active site of the enzyme and is converted into products. Once, the product is synthesized it leaves the enzyme and another substrate then binds to the enzyme. That's how enzyme catalyze many product formation.
