What is another name for fats that are insoluble in water?

Fats that are insoluble in water are commonly referred to as lipids. This classification includes a diverse group of compounds, such as triglycerides, phospholipids, and steroids, all of which share the characteristic of being hydrophobic or nonpolar. The hydrophobic nature of lipids is due to their long hydrocarbon chains, making them insoluble in water while still able to dissolve in nonpolar solvents. Understanding lipids is crucial in anatomy and physiology, as they play vital roles in cellular structure, energy storage, and signaling within the body.

The other options represent different macromolecules: amino acids are the building blocks of proteins, carbohydrates primarily serve as energy sources, and nucleotides are the fundamental units of nucleic acids. None of these correctly describe substances that are insoluble in water. Thus, lipid is the appropriate term for fats in this context.