Peptide bond
Peptide bonds (also known as amide bonds[1]) 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.
A peptide bond is a kind of linkage between two amino acids. It is also known as an amide bond. A peptide bond connects two amino acids, forming a dipeptide, and is associated with the loss of a water molecule. This process is called a condensation reaction. One perhaps surprising fact about peptide bonds is that they are very kinetically stable, in fact a peptide bond in a solution will last 1000 years, if no catalyst is present to disrupt it.
Many amino acids can be connected via peptide bonds, making a polypeptide. Each amino acid is then called a residue as it forms part of the polypeptide [2]. The ends of a polypeptide chain will be different because an alpha amino group is present at one end and an alpha carboxyl group present at the other. This gives the polypeptide chain polarity [3].