What does dipeptide mean?
A dipeptide is an organic compound made up of exactly two amino acid residues joined by a single peptide bond, which forms between the carboxyl group of one amino acid and the amino group of another, releasing a molecule of water. Dipeptides are the smallest peptides possible beyond single amino acids, sitting at the base of a hierarchy that extends to tripeptides, oligopeptides, and full proteins. In biochemistry and nutrition they matter for several reasons: protein digestion produces dipeptides alongside free amino acids, some dipeptides are absorbed directly across the intestinal wall via specialized transporters, and certain naturally occurring dipeptides — such as carnosine in muscle tissue or the artificial sweetener aspartame — have notable biological or commercial significance. The term belongs to formal scientific register and appears almost exclusively in biochemistry, physiology, food science, and medical literature, where precision about chain length distinguishes it from the broader term "peptide."
nounA molecule consisting of two amino acid residues joined by a single peptide bond, formed when the carboxyl group of one amino acid reacts with the amino group of another.
- A compound formed from two amino acid residues joined by one peptide bond.
"The enzyme carnosinase breaks down the dipeptide carnosine in muscle tissue."
"Aspartame is a methyl ester of a dipeptide composed of aspartic acid and phenylalanine."
"Protein digestion in the small intestine yields free amino acids and short chains such as dipeptides and tripeptides, which are absorbed through the intestinal wall."
Regular plural; used when referring to multiple molecules or to the class of two-residue peptides generally, often alongside "tripeptides" and "oligopeptides" in discussions of protein digestion.
"Intestinal brush-border enzymes release dipeptides that are then taken up by specialized transporters."
Carnosine, a humble dipeptide made of just two amino acids, helps buffer acidity in your muscles during intense exercise — proof that bigger isn't always better in biology.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of dipeptide
"Dipeptide" combines the prefix "di-", from the Greek "dis" meaning twice, with "peptide", coined in the early twentieth century from the German "Peptid", itself derived from the Greek root "pept-" meaning digested, related to "peptein", to digest. The term arose as chemists began classifying hydrolysis products of proteins by the number of amino acid residues in each fragment. It shares this digestive root with words such as pepsin, peptic, and dyspepsia, and forms an obvious series with tripeptide and polypeptide.
How dipeptide is actually used
"Dipeptide" is a technical term confined chiefly to biochemistry, nutrition science, medicine, and related academic contexts; it is rarely used outside scientific writing. It is countable and takes standard plural forms.
Easily confused with dipeptide
A peptide is any chain of linked amino acids of any length, whereas a dipeptide specifically contains exactly two amino acid residues.
A disaccharide consists of two sugar units joined together, while a dipeptide consists of two amino acids joined by a peptide bond.