Question
What are the monomers of a lipid?
Answer
The expected introductory answer is glycerol and fatty acids, when the worksheet uses “lipid” to mean a fat or triglyceride. A triglyceride contains one glycerol backbone joined to three fatty acid residues by ester bonds.
Strictly speaking, however, lipids do not have one universal set of monomers. Most familiar lipids are not polymers made by repeating a single kind of building block. Calling glycerol and fatty acids the “monomers of lipids” is a classroom shortcut.
Why the lipid class matters
A triglyceride is a fixed combination of a backbone and three attached chains, rather than a long repeating chain like a protein. Glycerophospholipids typically have two fatty acid tails and a phosphate-containing head group. Steroids, such as cholesterol, have a fused-ring framework and do not fit the glycerol-plus-three-fatty-acids model.
For this worksheet, give glycerol and fatty acids, then qualify the answer: these are the building components of fats, not universal monomers of every lipid.
Evidence boundary
The original worksheet asks about “a lipid” and uses a simplified fat model. The answer preserves that intended context while correcting the generalization: the 1:3 ratio describes triglycerides, not all lipids, and does not make lipids a repeating-monomer polymer class.
Sources
These references support the concepts and methods used in the explanation above.