<prompt> The conversion of a fatty acid to an active fatty acid is catalysed by which of the following enzymes?Acyl-CoA synthetaseEnoyl CoA hydrataseThiolaseAcyl CoA dehydrogenase  <response>: Fatty acids must first be converted to an active intermediate before they can be catabolized. This is the only step in the complete degradation of a fatty acid that requires energy from ATP. In the presence of ATP and coenzyme A, the enzyme acyl-CoA synthetase thiokinase catalyzes the conversion of a fatty acid or FFA to an active fatty acid or acyl-CoA, using one high-energy phosphate and forming AMP and PPi . The PPi is hydrolyzed by inorganic pyrophosphatase with the loss of a further high-energy phosphate, ensuring that the overall reaction goes to completion. Acyl-CoA synthetases are found in the endoplasmic reticulum, peroxisomes, and inside and on the outer membrane of mitochondria.HARPERS ILLUSTRATED BIOCHEMISTRY30th ed page no. 224 