Question

The helical structure of protein is stabilized by which of the following?

• A. Ionic bond
• B. Covalent bond
• C. van der Waals forces
• D. Hydrogen bond

Hint:

In proteins, hydrogen bonds between the peptide backbone stabilize the helical structure, particularly in the alpha-helix.

Answer 1

The Correct Option is D

Step 1: Understanding the stabilization of protein structure.
The helical structure of proteins, such as alpha-helix, is primarily stabilized by hydrogen bonds. These bonds form between the hydrogen atom attached to a nitrogen atom (from the peptide backbone) and the oxygen atom of a carbonyl group (from the peptide backbone) of another amino acid. Step 2: Analysis of options.
(A) Ionic bond: Ionic bonds do not play a significant role in stabilizing the helical structure of proteins.
(B) Covalent bond: While covalent bonds are important for the overall structure of proteins, they do not stabilize the helical conformation.
(C) van der Waals forces: van der Waals forces provide some stabilization, but they are weaker compared to hydrogen bonds in stabilizing the helical structure.
(D) Hydrogen bond: Correct — The helical structure of proteins is stabilized primarily by hydrogen bonds, which are crucial for the maintenance of the alpha-helix structure.
Step 3: Conclusion.
The correct answer is (D) because hydrogen bonds play a critical role in stabilizing the helical structure of proteins.