Lipids are hydrophobic or hydrophilic?

• A. Hydrophobic
• B. Hydrophilic
• C. Amphipathic
• D. Polar

Answer: (A)

Lipids are hydrophobic because they are largely nonpolar, with long hydrocarbon chains that do not form favorable interactions with water. Water is polar, so it stabilizes itself through hydrogen bonding, while lipids avoid mixing with water and tend to aggregate together to minimize contact with it. This nonpolar nature explains why lipids dissolve in nonpolar solvents and form the nonpolar interior of cell membranes. Some lipid molecules, like phospholipids, do have a hydrophilic (polar) head and a hydrophobic tail, making them amphipathic, but the overall behavior and classification of lipids as a group is hydrophobic.