What are proteins? What are proteins made of? What are the functions of proteins in the human body?

What are proteins? What are proteins made of? What are the functions of proteins in the human body? What foods contain protein?

Proteins are a large class of biological molecules made up of chains of amino acids called polypeptides. A single polypeptide can form a protein, although many proteins are composed of multiple polypeptide subunits.

Proteins have important functions in the body. In fact, this class of molecules is found in every cell and is essential for life.

A protein can be composed of a single polypeptide or multiple polypeptide subunits. Some proteins include non-peptide groups called cofactors. The cofactor can be an organic group (eg, coenzyme, prosthetic group) or an inorganic group (eg, metal or iron and sulfur ion).