Amide bond

An amide bond is a peptide bond. It is formed when the amine group of one amino acid forms a bond with the carboxyl group of another amino acid, resulting in the loss of a single water molecule^[1].

The peptide group (–CO–NH–) has partial double-bond characteristics due to the resonance of amides, where the nitrogen atom of the amide group is able to donate its lone pair of electrons to the carbon atom in the carboxyl group and push the electrons from the carbonyl C=O double bond towrds the oxygen atom, which forms an oxygen anion^[2].

The resonance double bond increases the stability and decreases the rotation about the peptide bond^[3].

References

1. ↑ Brenner S, Miller JH. Encyclopedia of Genetics. Academic Press. 2001.
2. ↑ WikiBooks. Structural Biochemistry/Organic Chemistry/Important Organic Reactions in Biochemistry/Peptide Bonding. 2012 [cited 05/12/18]. Available from: https://en.wikibooks.org/wiki/Structural_Biochemistry/Organic_Chemistry/Important_Organic_Reactions_in_Biochemistry/Peptide_Bonding
3. ↑ WikiBooks. Structural Biochemistry/Organic Chemistry/Important Organic Reactions in Biochemistry/Peptide Bonding. 2012 [cited 05/12/18]. Available from: https://en.wikibooks.org/wiki/Structural_Biochemistry/Organic_Chemistry/Important_Organic_Reactions_in_Biochemistry/Peptide_Bonding