What is the biological significance of lipids?

Lipids are one of the major biomolecules in the body. Composed of hydrogen, carbon, and oxygen molecules, lipids serve several critical metabolic functions in organisms 

1. Energy storage: Lipids are highly efficient energy storage molecules. They store more energy per gram compared to carbohydrates or proteins. When the body needs energy, lipids can be broken down into fatty acids and metabolized to provide a steady source of fuel, especially during periods of intense physical activity.
2. Energy Production: In addition to long-term energy storage, lipids are also used for immediate energy needs. Fatty acids are broken down through β-oxidation to produce adenosine triphosphate (ATP), the primary source of cellular energy.
3. Structural and functional framework of living cells: Lipids make up the bilayer of cell membranes, providing the structural framework for cells. The selectively permeable nature of the lipid bilayer is key to regulating the passage of molecules in and out of cells.
4. Cell Signaling: Some lipids serve as signaling molecules within cells transmitting signals from one cell to another. They are involved in various cellular processes, including intracellular communication, apoptosis, and inflammation.
5. Insulation & Protection: Lipids, particularly phospholipids, protect vital internal organs by cushioning them against pressure and mechanical injury. They also play a role in maintaining a constant internal climate by regulating body temperature.
6. Hormone Production: Steroid hormones, including testosterone, estrogen, and cortisol, which play critical roles in regulating various physiological processes, are derived from lipids.