Formation of `1^@` and secondary structure of proteins involves inkages

Options

A. Peptide linkage, H-bond
B. H-Bond, disulphide bond
C. Disulphide bond, peptide linkage
D. H-bond, H-bond

Answer

To answer the question regarding the formation of primary and secondary structures of proteins and the types of linkages involved, we can break down the solution into clear steps:

### Step-by-Step Solution:

1. **Understanding Primary Structure**:
- The primary structure of a protein refers to the specific sequence of amino acids linked together in a polypeptide chain.
- These amino acids are connected through a specific type of bond known as **peptide bonds** (or amide linkages).

2. **Formation of Peptide Bonds**:
- Peptide bonds are formed through a dehydration synthesis reaction, where the carboxyl group of one amino acid reacts with the amino group of another, releasing a molecule of water.
- This linkage is crucial as it determines the primary sequence of the protein.

3. **Understanding Secondary Structure**:
- The secondary structure of a protein refers to the local folded structures that form within a polypeptide due to interactions between the backbone of the amino acids.
- The most common types of secondary structures are the **alpha-helix** and **beta-pleated sheet**.

4. **Role of Hydrogen Bonds in Secondary Structure**:
- The secondary structure is stabilized by **hydrogen bonds** that form between the carbonyl oxygen of one amino acid and the hydrogen of the amide group of another amino acid.
- These hydrogen bonds are weaker than peptide bonds but are crucial for maintaining the overall shape of the protein.

5. **Conclusion**:
- Therefore, the primary structure of proteins involves **peptide linkages**, while the secondary structure involves **hydrogen bonding**.

### Final Answer:
- **Primary Structure**: Peptide linkages (amide bonds)
- **Secondary Structure**: Hydrogen bonds