Amide ($R-\mathrm{C}(=\mathrm{O})-\mathrm{N}{\mathrm{R}}^{\prime }{\mathrm{R}}^{\prime \prime }$)

Here an amide means a carbonyl group whose carbon is bonded directly to nitrogen; each of $R$, $R^{\prime }$ and $R^{\prime \prime }$ may be hydrogen or a group attached through carbon. A peptide bond contains this linkage. Chemical resonance distinguishes its nitrogen from that of an amine. ^[ref] and ^[ref]