What is one of the main functions of lipids in the body?

One of the main functions of lipids in the body is to form cell membranes and store energy. Lipids, which include fats and oils, play a critical role in maintaining the structure and integrity of cell membranes through the formation of a lipid bilayer. This bilayer acts as a barrier, allowing the cell to maintain a distinct internal environment while regulating the movement of substances in and out of the cell.

Additionally, lipids are highly efficient energy storage molecules. They provide more than double the amount of energy per gram compared to carbohydrates and proteins, making them an essential energy reserve for the body. This stored energy is particularly important during periods of fasting or extended physical activity when the body requires more fuel to sustain metabolic functions.

The other options do not accurately reflect the primary roles of lipids. While lipids are important for energy storage and membrane formation, they are not primarily involved in providing immediate energy, storing genetic information, or catalyzing biochemical reactions, which are functions attributed to carbohydrates, nucleic acids, and enzymes, respectively.