Final answer:
The oxidation of fatty acids, or beta-oxidation, primarily takes place in the mitochondria and also in peroxisomes for the very long chain fatty acids.
Step-by-step explanation:
The oxidation of fatty acids predominantly occurs in the mitochondria and to a lesser extent, in peroxisomes.
This process, known as beta-oxidation, begins in the cytoplasm where fatty acids are converted into fatty acyl CoA molecules.
These molecules then transport the fatty acids across the mitochondrial membrane.
Once inside the mitochondria, the fatty acid is broken down into two-carbon fragments in the form of acetyl CoA, which enters the citric acid cycle to produce ATP.
Peroxisomes also play a role in the oxidation of very long chain fatty acids, which are then further broken down in mitochondria.