The chemical bonding in peptide bonds is responsible for their __. Specifically, the resonance structure that accounts for the planarity of a peptide bond also makes such bonds __.
The carbon-nitrogen bond is strengthened by its __. Furthermore, the carbonyl carbon atom is __ and __ than are the carbonyl carbon atoms in more reactive compounds.
As a result, to promote peptide-bond cleavage, an enzyme must __ at a normally __