Why Do Amide Bonds Exist as Reasonably Stable S-Cis or S-Trans

question 41

Multiple Choice

Why do amide bonds exist as reasonably stable s-cis or s-trans isomers at room temperature?

• A)These amide bonds are not stable.
• B)There is partial double bond character between the carbonyl carbon and the nitrogen atom.
• C)The oxygen atom is hydrogen-bonded with the nitrogen atom.
• D)The side-chains can form hydrogen bonds.