Which of the following is NOT a subclass of lipids?

Lipids are a diverse group of organic compounds that are primarily hydrophobic and include several subclasses, such as fats, phospholipids, and waxes. Fats, which are also known as triglycerides, are made up of glycerol and fatty acids and serve as a major energy storage form in organisms. Phospholipids are crucial components of cell membranes, forming a bilayer that serves as a barrier to protect the cell and regulate the passage of substances in and out. Waxes provide protective coatings for plants and animals, contributing to water retention and preventing desiccation.

In contrast, sugars belong to a different class of biomolecules known as carbohydrates. They are characterized by their hydrophilic nature and are composed of carbon, hydrogen, and oxygen in specific ratios, usually in the form of monosaccharides or polysaccharides. Sugars serve as a primary energy source for cells and also play roles in cellular structure and signaling but do not share the characteristics and functions associated with lipids. Therefore, sugars are correctly identified as not being a subclass of lipids.