A protein is a biological molecule made of one or more chains of amino acids folded into structures that enable specific functions.
Proteins perform a wide range of functions, including building and repairing tissues, transporting substances, supporting immune responses, regulating biological processes, and catalyzing chemical reactions as enzymes.
Dietary proteins are broken down into amino acids and smaller peptides during digestion. The body then uses these components to make its own proteins and other molecules.
QUICK FACT
Protein is not a single substance. The body contains thousands of different proteins with different structures and functions.
COMMONLY CONFUSED WITH
- Amino acid: a building block from which proteins are made.
- Enzyme: a protein or, less commonly, an RNA molecule that accelerates a chemical reaction.
SEE ALSO
- Amino Acid
- Enzyme
- Nutrition
- Metabolism
