H2CO3 is the molecular formula for

A. A long fatty acid chains: Triglycerides with long fatty acid chains can be either saturated or unsaturated. The chain length affects melting point to some extent but does not solely determine whether the fat is a solid or liquid at room temperature.

B. Saturated fatty acids: Saturated triglycerides have no double bonds, making their fatty acid chains tightly packed. This structure leads to higher melting points, so they are generally solid at room temperature, as seen in butter or lard.

C. Unsaturated fatty acids: Unsaturated triglycerides contain one or more double bonds in their fatty acid chains, which introduce kinks that prevent tight packing. This structure lowers their melting point, making them liquid at room temperature and therefore classified as oils.

D. A high water content: Triglycerides are hydrophobic molecules that do not mix with water. Their classification as oils or fats depends on the degree of saturation of fatty acids, not water content, since triglycerides themselves contain virtually no water.

A. Proteins: Proteins serve as the primary structural components of cells and tissues. They form muscles, connective tissue, enzymes, and cell membranes, providing strength, support, and functional versatility throughout the body.

B. Carbohydrates: Carbohydrates primarily provide energy and serve as short-term fuel and structural components like glycogen, but they are not the main structural material of the body.

C. Lipids: Lipids function as energy storage, insulation, and components of cell membranes, but they do not provide the bulk structural framework of tissues.

D. Nucleic acids: Nucleic acids such as DNA and RNA store and transmit genetic information but do not serve as the primary structural material for the body.