The metabolic pathway in which fats are metabolized to release energy. Fatty-acid oxidation occurs continually but does not become a major source of energy until the animal's carbohydrate resources are exhausted, for example during starvation. Fatty-acid oxidation occurs chiefly in mitochondria in animal cells, and in peroxisomes in plant cells. A series of reactions cleave off two carbon atoms at a time from the hydrocarbon chain of the fatty acid. These two-carbon fragments are combined with coenzyme A to form acetyl coenzyme A (acetyl CoA), which then enters the Krebs cycle. The formation of acetyl CoA occurs repeatedly until all the hydrocarbon chain has been used up. See also glyoxylate cycle.
Subjects: Biological Sciences.