The peptide bond
A) is most stable in the cis configuration.
B) has a mix of single and double bond characters.
C) can rotate around the carbonyl and N bond but not around the -carbon and N bond.
D) can function as a weak acid and weak base.

Question

The peptide bond
A) is most stable in the cis configuration. 
B) has a mix of single and double bond characters. 
C) can rotate around the carbonyl and N bond but not around the -carbon and N bond. 
D) can function as a weak acid and weak base.

Quizplus · Accepted Answer

The peptide bond has characteristics of both a single and double bond, meaning it has partial double bond character, which is responsible for the planar structure of the peptide bond. However, it cannot rotate around the carbon-nitrogen bond, which restricts the conformational flexibility of the peptide backbone. The cis configuration of the peptide bond is less stable than the trans configuration. The peptide bond does not act as an acid or a base under physiological conditions.

The Peptide Bond