The four roles of proteins are to help provide structure, transport other molecules around the body, facilitate essential biochemical reactions in the body and act as channels for the passage of important molecules to and from the cells. The broad protein types are enzymes and structural, transport and channel proteins.
Proteins are complex molecules that perform many critical functions in the body. They are made up of chains of amino acids, and the sequence of these amino acids determines both the type and function of the protein. Proteins are diverse are in structure, characteristics and function. Some proteins are hydrophilic, while others are hydrophobic. Some proteins frequently change shape, while others remain intact.