What is the term for a substance composed of fatty acids and glycerol?

The term used to describe a substance composed of fatty acids and glycerol is lipid. Lipids are a diverse group of organic compounds that play various roles in biological systems, including serving as energy storage molecules and key components of cell membranes. The structure of lipids generally includes long hydrocarbon chains (fatty acids) attached to a glycerol molecule, which can be found in forms such as triglycerides, phospholipids, and sterols.

Understanding the structure is crucial: fatty acids consist of long carbon chains with a carboxyl group at one end, while glycerol is a three-carbon alcohol. When these fatty acids are esterified to the glycerol, they form triglycerides, which are a primary storage form of energy in living organisms. This is different from carbohydrates, which are made of sugar molecules; proteins, built from amino acids; and nucleic acids, which consist of nucleotide monomers. Each of these other categories has its own unique structural and functional characteristics that distinguish them from lipids.