Cholesterol is a

Cholesterol is a

• A. Glycolipid
• B. Protein
• C. Carbohydrate
• D. Amphipathic lipid

Answer: (D)

Cholesterol is being tested for its dual nature: it is a lipid with both hydrophobic and polar features. Its bulky four-ring steroid structure and hydrocarbon tail are largely nonpolar, which makes cholesterol mostly water-insoluble. At one end, there is a single hydroxyl group that is polar, giving it a small region of polarity. This combination makes cholesterol amphipathic. In cell membranes, the nonpolar part sits in the interior of the lipid bilayer while the polar hydroxyl group can interact with the aqueous environment near the membrane surface. It’s not a carbohydrate, protein, or glycolipid because it lacks sugar moieties and amino acid chains, so the best classification is an amphipathic lipid.

Cholesterol is being tested for its dual nature: it is a lipid with both hydrophobic and polar features. Its bulky four-ring steroid structure and hydrocarbon tail are largely nonpolar, which makes cholesterol mostly water-insoluble. At one end, there is a single hydroxyl group that is polar, giving it a small region of polarity. This combination makes cholesterol amphipathic. In cell membranes, the nonpolar part sits in the interior of the lipid bilayer while the polar hydroxyl group can interact with the aqueous environment near the membrane surface. It’s not a carbohydrate, protein, or glycolipid because it lacks sugar moieties and amino acid chains, so the best classification is an amphipathic lipid.