Question

The helical structure of a protein is stabilized by:

• A. Dipeptide bonds
• B. Hydrogen bonds
• C. Ether bonds
• D. Peptide bonds

Hint:

In proteins, hydrogen bonding between the backbone atoms of amino acids stabilizes the secondary structures like \(\alpha\)-helices and \(\beta\)-sheets.

Answer 1

The Correct Option is B

Step 1: Understanding protein structure. Proteins have different levels of structure: primary, secondary, tertiary, and quaternary. The \(\alpha\)-helix and \(\beta\)-sheet are common secondary structures. 
Step 2: Role of hydrogen bonding. The \(\alpha\)-helical structure of proteins is stabilized by hydrogen bonds formed between the carbonyl oxygen of one amino acid and the amide hydrogen of another amino acid four residues away in the chain: \[ {C=O} \cdots {H-N} \] These hydrogen bonds help maintain the spiral shape of the helix. 
Step 3: Eliminating incorrect Option. 
- Dipeptide bonds (Option A): Incorrect, as they only link two amino acids. 
- Ether bonds (Option C): Incorrect, as ether bonds are not present in proteins. 
- Peptide bonds (Option D): Incorrect, as peptide bonds link amino acids but do not stabilize the helical structure. 
Since hydrogen bonding is responsible for stabilizing the helical structure, the correct answer is (B) Hydrogen bonds.