A peptide is one or more amino acids linked by chemical bonds. The term also refers to the type of chemical bond that joins the amino acids together. A series of linked amino acids is a polypeptide. The cell's proteins are made from one or more polypeptides.


The term "peptides" refers to a series of amino acids linked together. Amino acids are the basic unit that make proteins, and a short series of those--short chain of amino acids--is called a peptide. Peptides are then organized in more complex structures, which are called proteins. And proteins are the building blocks of a cell.

- Fabio Candotti, M.D.