Question

Which of the following bonds is responsible for maintaining the secondary structure of proteins?

• A. Peptide bond
• B. Hydrogen bond
• C. Disulfide bond
• D. Ionic bond

Hint:

Remember: Primary structure = Covalent (Peptide) bonds; Secondary structure = Hydrogen bonds; Tertiary structure = Hydrophobic, Ionic, Disulfide, and van der Waals interactions.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The secondary structure of a protein refers to the local spatial arrangement of its main-chain atoms, without regard to the conformation of its side chains or its relationship to other segments.
The most common types of secondary structures are the \(\alpha\)-helix and the \(\beta\)-pleated sheet.
Step 2: Detailed Explanation:
The stability of these secondary structures is primarily due to hydrogen bonds formed between the carbonyl oxygen (\(C=O\)) of one peptide bond and the amide hydrogen (\(N-H\)) of another peptide bond.
- Peptide bonds (Option A) are covalent bonds that define the primary structure (the sequence of amino acids).
- Disulfide bonds (Option C) and Ionic bonds (Option D) are primarily involved in stabilizing the tertiary and quaternary structures of proteins.
In an \(\alpha\)-helix, the hydrogen bond forms between the \(n^{th}\) and the \((n+4)^{th}\) amino acid residue.
Step 3: Final Answer:
Therefore, the hydrogen bond is the key interaction responsible for maintaining the secondary structure of proteins.