Triglycerides are made up of which components?

• A. Glycerol only
• B. Glycerol + 2 fatty acids
• C. Glycerol + 3 fatty acids
• D. Fatty acids only

Answer: (C)

Triglycerides are built from a glycerol backbone with three fatty acids attached. Glycerol is a three-carbon molecule with a hydroxyl group on each carbon, and during formation each hydroxyl bonds to a fatty acid through an ester linkage, yielding three ester bonds and three fatty acid tails. This structure explains why triglycerides are a dense energy store and why fats are nonpolar.

So the components are glycerol plus three fatty acids. If you had only glycerol, or only two fatty acids, you’d have a glycerol molecule or a diacylglycerol, not a triglyceride. Fatty acids alone lack the glycerol backbone needed for a triglyceride.