Lipid

**Semantic type:** Classification|Organic Chemical

**Definition:** A class of hydrocarbon-containing organic compounds. Lipids are insoluble in water but soluble in nonpolar solvents and play important roles in living organisms: these roles include functioning as energy storage molecules, serving as structural components of cell membranes, and constituting important signaling molecules. Lipids can be subdivided into 2 groups: fatty acids and glycerides.

**Synonyms:** - Lipids