Peptides

Acompound composed of two or more amino acids in which a carboxyl group of oneis linked to amino acid monomers  f another group in a short chain. While theyhave been referred to as ‘small proteins’, peptides differ in terms ofstructure consisting of 50 or more amino acids.  Moreover, proteins consist of one or morepolypeptides.  Naturally-occurring milkpeptides are formed from the milk protein casein whendigestive enzymes break it down and they important nutrients in breast-fedinfants (e.g., in bone growth, development of immune system).  

See Amino acids, Endorphins, Enzyme, Glycoproteins, Gonadotropin releasing hormone (GnRH), Growth hormone (or somatotropin), Hormones, Hypothalamic-pituitary-adrenal (HPA) axis, Ligands, Peptides, Polypeptides, Prolactin, Proteins