Which process occurs within the mitochondria to convert fatty acids into acetyl CoA?

The process that occurs within the mitochondria to convert fatty acids into acetyl CoA is beta oxidation. This metabolic pathway involves the oxidation of fatty acids to generate acetyl CoA molecules, which can then enter the citric acid cycle (or Krebs cycle) to be used for energy production.

During beta oxidation, long-chain fatty acids undergo a series of enzymatic reactions where they are sequentially broken down into two-carbon units, each of which is released as acetyl CoA. This process involves the activation of the fatty acid to form fatty acyl-CoA, followed by a series of dehydrogenation, hydration, and thiolysis reactions. The resulting acetyl CoA can then be utilized in various metabolic pathways, particularly for energy production.

In contrast, glycolysis does not take place in the mitochondria and is the pathway that converts glucose into pyruvate in the cytosol. The citrate cycle, also known as the citric acid cycle or Krebs cycle, uses the acetyl CoA produced from beta oxidation for further energy extraction but does not directly convert fatty acids into acetyl CoA. Fatty acid synthesis occurs in the cytosol, where acetyl CoA is used to synthesize fatty acids, not