Fatty acids serve as building blocks for lipids and fuel molecules. They are broken down into acetyl CoA through a process of beta-oxidation within mitochondria. This provides energy through the citric acid cycle. Fatty acids are stored as triglycerides in adipose tissue and mobilized through lipolysis when energy is needed. Dietary lipids undergo digestion and are absorbed through the intestine as fatty acids, transported by chylomicrons before being oxidized or stored.