Question

An unknown sample known to contain either triglycerides or phospholipids is placed in water. The sample forms a separate layer on top of the water, with no mixing in the bulk volume of water. What type of lipid does the sample contain, and what structural element is responsible for the sample’s behavior in water? a. Triglycerides, double bonds in fatty acid tails b. Triglycerides, ester linkages c. Triglycerides, long-chain hydrocarbon tails d. Phospholipids, ester linkages e. Phospholipids, glycerol backbone

Answer 1

Answer: Option C) Triglycerides, long-chain hydrocarbon tails

Explanation:

Triglycerides are lipids, with three fatty acids (the same or different) having long hydrocarbon tails.

The hydrocarbon tails in triglycerides is the structural element that makes it insoluble in water as seen in the sample forming a separate layer on top of the water because it does not form hydrogen bonds with water molecules i.e hydrophobic

Thus, option C is the answer