The bonds occur between carbonyl and amine groups in the amide repeat unit. HATU is commonly encountered in amine acylation reactions (i.e., amide formation). Structures are alternately bound via amide and ester bridges. And an amine by hoffman degradation of the amide in the presence of alkali hypoclorites. In addition, the peptide backbone, with carbonyl and amide N groups is often employed. Type B is derived by alkaline hydrolysis containing 18% nitrogen and no amide groups. A polyamide is a Polymer with repeating units linked by amide bonds. They are cysteine proteases that cleave the amide bond between the two proteins. It is the simplest amide derived from acetic acid. Chemical structure of this aramid consists of linearly substituted aromatic rings linked by amide groups. It is a secondary amide between glucosamine and acetic acid. It is an amide of nicotinic acid. Esters are prone to producing allergic reactions, which may necessitate the use of an amide. A water molecule is released during formation of each amide bond. Sometimes labeled as a fatty acid primary amide (FAPA), it is biosynthesized from N-oleoylglycine.