Peptides are composed of amino acids joined by amide bonds. Which of the following statements is not correct ?

Options

A. Amide groups are more resistant to hydrolysis than are similar ester groups
B. `p - pi` resonance stabilises the amide bond
C. Stable conformations of peptide are restricted to those having planar amide groups
D. Amide groups doesnot participate in hydrogen bonding

Explanation

To determine which statement about peptides and amide bonds is not correct, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Amide Bonds**:
- Peptides are formed by amino acids linked together through amide bonds (also known as peptide bonds). An amide bond is characterized by a carbonyl group (C=O) directly attached to a nitrogen atom (N).

2. **Analyzing Each Statement**:
- **Option A**: "Amide groups are more resistant to hydrolysis than similar esters."
- **Explanation**: Amide bonds are indeed more stable and resistant to hydrolysis compared to ester bonds due to the resonance stabilization and the presence of nitrogen, which can participate in hydrogen bonding.
- **Conclusion**: This statement is **correct**.

- **Option B**: "P pi resonance stability of the amide bond."
- **Explanation**: The amide bond exhibits resonance due to the lone pair of electrons on the nitrogen atom, which can delocalize into the carbonyl group. This resonance contributes to the stability of the amide bond.
- **Conclusion**: This statement is **correct**.

- **Option C**: "Stable conformations of peptides are resistant due to the planar amide group."
- **Explanation**: The amide bond is planar due to the partial double bond character, which restricts rotation. This planarity is crucial for the stability of peptide structures.
- **Conclusion**: This statement is **correct**.

- **Option D**: "Amide groups do not participate in hydrogen bonding."
- **Explanation**: Amide groups can participate in hydrogen bonding due to the presence of the nitrogen atom (which can act as a hydrogen bond donor) and the carbonyl oxygen (which can act as a hydrogen bond acceptor). Therefore, this statement is false.
- **Conclusion**: This statement is **not correct**.

3. **Final Answer**:
- The statement that is not correct is **Option D**: "Amide groups do not participate in hydrogen bonding."