bétaoxidáció

Bétaoxidáció is the metabolic process by which fatty acid molecules are broken down in the mitochondria and peroxisomes. This process occurs in the cytoplasm and removes two-carbon units from the carboxyl end of the fatty acid chains. Each cycle of beta-oxidation produces one molecule of acetyl-CoA, along with reduced nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FADH2).

The acetyl-CoA produced can then enter the citric acid cycle for further energy production. The NADH and FADH2 are used in the electron transport chain to generate ATP, the primary energy currency of the cell. Beta-oxidation is a crucial pathway for energy generation, especially during fasting or prolonged exercise when glucose levels are low.

The overall process involves four key enzymatic steps: dehydrogenation, hydration, another dehydrogenation, and thiolysis. These steps systematically shorten the fatty acid chain by two carbons per cycle. The number of cycles required depends on the length of the fatty acid chain. For example, a 16-carbon fatty acid like palmitate will undergo seven cycles of beta-oxidation.

This pathway is tightly regulated to meet the body's energy demands. Defects in beta-oxidation can lead to various metabolic disorders, often characterized by the accumulation of fatty acids in tissues and impaired energy production.