What is the term used for a short chain of amino acids?

A short chain of amino acids is referred to as a peptide. This term specifically denotes a molecule formed when two or more amino acids are linked together through peptide bonds. When amino acids are joined together, they lose a molecule of water for each bond formed in a process known as dehydration synthesis.

While proteins are composed of one or more polypeptides and serve a variety of functions in biological systems, they are generally larger and more complex structures than simple peptides. Polypeptides consist of longer chains of amino acids, typically consisting of 20 or more, and can fold into functional proteins. Enzymes are specialized proteins that catalyze biochemical reactions, but the term itself does not define the chain length of the amino acids involved. Therefore, "peptide" accurately describes the shorter chain of amino acids, making it the correct response.