Question

Which of the following statements is true about a peptide bond

 (\( \text{RCONHR'} \))?

• A. \( \text{It is non-planar.} \)
• B. \( \text{It is capable of forming a hydrogen bond.} \)
• C. \( \text{The cis configuration is favoured over the trans configuration.} \)
• D. \( \text{Single bond rotation is permitted between nitrogen and the carbonyl group.} \)

Hint:

Peptide bonds are rigid and planar, and their ability to form hydrogen bonds is crucial for stabilizing protein structures.

Answer 1

The Correct Option is B

A peptide bond forms between the carboxyl group of one amino acid and the amino group of another. This bond has the following characteristics: \[ \text{Peptide Bond: RCONHR'} \] Explanation of the properties of peptide bonds:
1. The peptide bond exhibits planarity due to the partial double-bond character, which arises from resonance between the carbonyl and nitrogen atoms.
2. The \( \text{NH} \) group in the peptide bond can act as a hydrogen bond donor, and the \( \text{C=O} \) group can act as a hydrogen bond acceptor, allowing the formation of hydrogen bonds.
3. The trans configuration is preferred over the cis configuration to minimize steric clashes between the side chains of adjacent amino acids.
4. Rotation is restricted around the bond between nitrogen and carbonyl due to its partial double-bond character.
Final Answer: \[ \boxed{\text{It is capable of forming a hydrogen bond.}} \]