A true statement about hydrophobic interactions is that they: A. involve the ability of water to denature proteins. B. primarily involve the effect of polar solutes on the entropy of aqueous systems. C. do not contribute to the structure of water-soluble proteins. D. are the driving force in the formation of micelles of amphipathic compounds in water. E. have bonding energies of approximately 0.20
The Correct Answer and Explanation is :
The correct answer is D. are the driving force in the formation of micelles of amphipathic compounds in water.
Explanation:
Hydrophobic interactions are non-covalent interactions that occur when non-polar substances aggregate in the presence of water, which is a polar solvent. Water molecules tend to form hydrogen bonds with each other, and this creates an ordering around hydrophobic molecules, which reduces entropy (the randomness of the system). In order to minimize this disruption, hydrophobic molecules tend to cluster together, reducing the surface area in contact with water and increasing the entropy of the system. This is a key feature in the formation of structures like micelles.
A micelle forms when amphipathic molecules (those with both hydrophobic and hydrophilic parts, like soaps or detergents) are placed in water. The hydrophobic (non-polar) parts of the molecules group together in the center, away from water, while the hydrophilic (polar) parts interact with water. This clustering of hydrophobic parts is driven by hydrophobic interactions and results in the formation of stable structures like micelles. This helps the system reduce its overall free energy by maximizing the favorable interactions between the polar water molecules and the hydrophilic parts of the amphipathic compounds.
Explanation of Incorrect Answers:
- A. Involve the ability of water to denature proteins: Hydrophobic interactions contribute to protein folding, not denaturation. Denaturation typically involves breaking various bonds, including hydrogen bonds, but hydrophobic interactions are critical in the stabilization of the folded structure.
- B. Primarily involve the effect of polar solutes on the entropy of aqueous systems: Hydrophobic interactions mainly focus on the effect of non-polar solutes on entropy, not polar solutes. Polar solutes tend to dissolve well in water because they interact favorably with the solvent, whereas hydrophobic solutes do not.
- C. Do not contribute to the structure of water-soluble proteins: This is incorrect, as hydrophobic interactions are crucial for the folding and stability of water-soluble proteins. The hydrophobic core of proteins helps them maintain their three-dimensional structure.
- E. Have bonding energies of approximately 0.20: Hydrophobic interactions are not typically described by specific bonding energies; they are a result of the exclusion of water from non-polar regions, contributing to molecular aggregation