Which of the following substances are classified as lipids?

Lipids are a diverse group of hydrophobic or amphipathic organic molecules that serve various functions in living organisms, including energy storage, structural components of cell membranes, and signaling molecules. The substances listed in the correct answer—fats, oils, waxes, and steroids—are all classic examples of lipids.

Fats and oils, which are triglycerides, are formed from glycerol and fatty acids, and they play a critical role in long-term energy storage. Waxes, which are long-chain fatty acids linked to long-chain alcohols, provide protective coatings in various organisms. Steroids, on the other hand, are characterized by a four-ring carbon structure and play important roles in cellular signaling and maintaining membrane fluidity.

The other options mentioned in the question refer to categories of biological macromolecules that are distinct from lipids. For example, proteins are made of amino acids and are primarily involved in catalyzing biochemical reactions and providing structural support. Carbohydrates, like simple sugars, are primarily involved in energy provision and are typically hydrophilic. Amino acids, while crucial as building blocks of proteins, are not lipids, and nucleic acids (like DNA and RNA) are involved in the storage and transmission of