Fatty acids play vital roles in biological systems by serving as key components of lipids, which are essential for cellular structure and energy storage. They contribute to the formation of cell membranes, where phospholipids, composed of fatty acids, create a bilayer essential for maintaining cellular integrity. Fatty acids also act as signaling molecules and precursors for various biological compounds, influencing inflammation, metabolism, and cellular communication. Additionally, they provide energy through beta-oxidation, which converts fatty acids into usable energy forms such as ATP during cellular respiration.