14. On the molar scale which of the following interaction in a nonpolar environment provides the highest contribution to the bio-molecule?

    (1) van der Walls interaction
    (2) Hydrogen bonding
    (3) Salt bridge
    (4) Hydrophobic interaction

Highest Contributing Interaction in a Nonpolar Solution for Biomolecules

Understanding Biomolecular Interactions
Biomolecules interact using multiple non-covalent forces that affect their structure, function, and stability. In a nonpolar environment, the prevalent interaction is not the same as what happens in aqueous (polar) solutions.

Among the most important interactions:

Van der Waals interactions (Weak but additive)

Hydrogen bonding (Strong in polar solvents)

Salt bridges (Ionic interactions based on polarity)

Hydrophobic interactions (Driving force in nonpolar solutions)

Examining the Interaction Contributions

1. Van der Waals Interactions

Van der Waals interactions are loose intermolecular attractions that occur through temporary dipoles. Though they are substantial in packing of molecules, their effect is smaller in contrast to other forces within a nonpolar surroundings.

2. Hydrogen Bonding

Hydrogen bonds form between electronegative atoms (O, N) and hydrogen. The interactions are most important in polar environments but have less to contribute in nonpolar environments owing to the fact that there is no strong dipole-dipole interaction present.

3. Salt Bridges

Salt bridges are electrostatic interactions between negatively and positively charged groups within biomolecules. They are very dependent on the media and are much stronger in low dielectric (nonpolar) media but are not predominant in fully hydrophobic media.

4. Hydrophobic Interactions (Highest Contribution) ✅

Hydrophobic interactions are seen when nonpolar molecules come together to reduce contact with a polar solvent. In a nonpolar environment, hydrophobic interactions prevail since there is no competing solvent effect.

For biomolecules such as proteins and lipids:

Hydrophobic residues come together, stabilizing structures.

Membrane formation is a result of hydrophobic interactions.

Protein folding is directed by hydrophobic core formation.

Correct Answer: (4) Hydrophobic Interaction
Importance of Hydrophobic Interactions in Biomolecules
1. Protein Folding & Stability
Proteins fold into specific 3D structures due to hydrophobic interactions, ensuring functional stability.

2. Membrane Formation
Cell membranes are made of lipid bilayers where hydrophobic tails aggregate, creating a protective barrier.

3. Enzyme-Substrate Binding
Hydrophobic interactions often enhance enzyme-substrate affinity, influencing biological reactions.

Conclusion
In a nonpolar medium, the strongest interaction that plays a role in biomolecular stability is the hydrophobic interaction. They are responsible for protein folding, molecular assembly, and membrane formation and thus play a crucial role in biological systems.