Which class of macromolecules does not typically dissolve in water?

Fats and lipids are classified as hydrophobic macromolecules, meaning they do not easily dissolve in water. This characteristic is primarily due to their non-polar nature; lipids are composed largely of long hydrocarbon chains that repel water molecules. In contrast, proteins, carbohydrates, and nucleic acids tend to have polar or charged functional groups that allow them to interact with water, leading to their solubility. For example, many proteins have polar amino acid side chains that facilitate their dissolution in aqueous environments, while carbohydrates typically have hydroxyl groups that can form hydrogen bonds with water. Thus, fats and lipids are distinct in their lack of solubility in water, making them the correct answer in this context.