Peptide bond
From Free net encyclopedia
A peptide bond is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing a molecule of water (H2O). This is a dehydration synthesis reaction, and usually occurs between amino acids.
The resulting C-NO bond is called a peptide bond, and the resulting molecule is called an amide. Polypeptides and proteins are chains of amino acids held together by peptide bonds. The backbone of PNA is also held together by peptide bonds.
A peptide bond can be broken by amide hydrolysis (the adding of water). The peptide bonds in proteins are metastable, meaning that in the presence of water they will break spontaneously, releasing about 10 kJ/mol of free energy, but this process is extremely slow. In living organisms, the process is facilitated by enzymes. Living organisms also employ enzymes to form peptide bonds; this process requires free energy. The wavelength of absorbance for a peptide bond is 190-230nm.bg:Пептидна връзка da:Peptidbinding de:Peptidbindung es:Enlace peptídico fr:Liaison peptidique ko:펩타이드 결합 io:Peptida ligo he:קשר פפטידי ja:ペプチド結合 no:Peptidbinding pl:Wiązanie peptydowe pt:Ligação peptídica ru:Пептидная связь sv:Peptidbindning zh:肽键