Peptide bond

Peptide bonds (also known as amide bonds) are the bonds that are found between two monomer units of amino acids in a polypeptide chain. They are created through condensation reacctions in which a molecule of water (H₂O) is removed.  The water is made by combining an hydroxyl group (OH) of one amino acid with an Hydrogen from the amino group (NH₂).  The two amino acids then become linked by a new peptide bond and is called a dipeptide . Polypeptide chains are essentially made up of amino acids linked together by these peptide bonds  and this linear sequence forms the the primary sturcture of a protein. Making the peptide bond occurs in the ribosomes during a step in protein sythesis called translation.

The peptide bond is a stable covalent bond and is said to be a rigid planar bond because it has a partial double bond character. The peptide bond is constantly switching between a single and a double bond.

Peptide bonds can also be easily broken by hydolysis (amide hydrolysis).  This is completely the opposite to condensation, whereby water is added to the dipeptide/polypeptide and the peptide bond breaks to give its two constituent amino acids.