Any of a group of organic compounds comprising two or more amino acids linked by peptide bonds. These bonds are formed by the reaction between adjacent carboxyl (–COOH) and amino (–NH2) groups with the elimination of water (see illustration). Dipeptides contain two amino acids, tripeptides three, and so on. Polypeptides contain more than ten and usually 100–300. Naturally occurring oligopeptides (of less than ten amino acids) include the tripeptide glutathione and the pituitary hormones vasopressin and oxytocin, which are octapeptides. Peptides also result from protein breakdown, e.g. during digestion.
Peptide
https://www.qmul.ac.uk/sbcs/iupac/AminoAcid/ Information about IUPAC nomenclature of peptides
Any of a group of organic compounds comprising two or more amino acids linked by peptide bonds. These bonds are formed by the reaction between adjacent carboxyl (–COOH) and amino (–NH2) groups with the elimination of water (see illustration). Dipeptides contain two amino acids, tripeptides three, and so on. Polypeptides contain more than 20 and usually 100–300. Naturally occurring oligopeptides (of less than 20 amino acids) include the tripeptide glutathione and the pituitary hormones antidiuretic hormone and oxytocin, which are octapeptides. Peptides also result from protein breakdown, e.g. during digestion.
Formation of a peptide bond