Phospholipids are composed of which components?

• A. Three fatty acids
• B. Glycerol with two phosphate groups
• C. Two fatty acids and a phosphate attached to glycerol
• D. One fatty acid with phosphate

Answer: (C)

Phospholipids are built around a glycerol backbone that carries two nonpolar fatty acid tails and a single phosphate-containing head. The two fatty acids form the hydrophobic part, while the phosphate group creates a hydrophilic, water-attracting head. This arrangement is what lets phospholipids form cellular membranes with a bilayer structure, tails tucked inward and heads facing outward.

The description that fits this structure is two fatty acids and a phosphate attached to glycerol, which captures both the hydrophobic tails and the hydrophilic phosphate head on the glycerol backbone. The other options don’t describe this arrangement: a triglyceride would have three fatty acids, not two; a glycerol with two phosphate groups would lack the fatty acid tails required for the membrane-forming amphipathic character; and a molecule with only one fatty acid and a phosphate isn’t the typical phospholipid structure.