Question

Hydrophobic interactions are mainly driven by

• A. Electrostatic attraction
• B. Entropy increase of water
• C. Covalent bonding
• D. Hydrogen bonding

Hint:

Hydrophobic interactions are driven primarily by: \[ \boxed{\text{Increase in entropy of water}} \] This principle explains protein folding, lipid bilayer formation, and many biological self-assembly processes.

Answer 1

The Correct Option is B

Concept: Hydrophobic interactions occur when non-polar molecules or non-polar regions of molecules aggregate together in an aqueous environment. These interactions play an important role in protein folding, membrane formation, and molecular recognition.

Step 1: Behavior of non-polar molecules in water.
Water molecules form extensive hydrogen-bond networks. When a non-polar molecule is introduced into water, surrounding water molecules become highly ordered around it. This ordering decreases entropy.

Step 2: Formation of hydrophobic interactions.
When non-polar molecules cluster together, the total surface area exposed to water decreases. As a result, many water molecules are released back into the bulk solution. \[ \boxed{\text{Increase in disorder of water}} \] This increases the entropy of the system.

Step 3: Reason for stabilization.
Hydrophobic interactions are not caused directly by attraction between hydrophobic molecules. Instead, they occur because clustering increases the entropy of surrounding water molecules. \[ \boxed{\Delta S_{\text{water}} > 0} \] Therefore, the process becomes thermodynamically favorable. Final Answer: \[ \boxed{Option (B) is correct \]