Answer: A protein and an active site.
Step-by-step explanation:
An enzyme is a molecule that accelerate chemical reactions. The molecules upon which they act are called substrates, and the enzyme converts it into different molecules known as products.
Enzymes are made of:
- A protein portion: a globular protein part called apoenzyme which consists of a long chain of amino acids
- An active site: the region of an enzyme where substrate molecules binds, and it is made of residues that form temporary bonds with the substrate and residues that catalyse a reaction of that substrate.