Peptide Bond
Also known as: amide bond · peptide linkage
The covalent amide bond linking amino acids into a peptide chain — the defining structural feature of every peptide.
A peptide bond is the covalent chemical bond that joins two amino acids: the carboxyl (–COOH) group of one reacts with the amino (–NH₂) group of the next, releasing a molecule of water in a condensation reaction and forming a –CO–NH– (amide) linkage.
Chaining amino acids this way builds a peptide; the bonds form the molecule’s backbone, from which the side chains project. The bond is planar and partially rigid, which shapes how a peptide folds.
Breaking a peptide bond (hydrolysis) is how peptides are degraded — by enzymes in the body and, more slowly, by water in solution, which is why peptides are supplied lyophilised.
RELATED TERMS
Amino Acid
The building-block molecules of peptides and proteins; each contributes one residue to the chain.
Amino-Acid Sequence
The specific order of amino-acid residues in a peptide — its "primary structure" — which dictates shape and activity.
N-terminus & C-terminus
The two ends of a peptide chain: the N-terminus has a free amino group, the C-terminus a free carboxyl group.
Tripeptide / Tetrapeptide
Short peptides named for their residue count — three (tri), four (tetra), five (penta) amino acids.
Half-Life
The time for a compound’s concentration to fall by half — a key determinant of dosing frequency in research.
Educational content, not medical advice. All products supplied for research purposes only — not for human consumption.