Fatty Acid Oxidation Yields Large Amounts of ATP

Fatty Acid Oxidation Yields Large Amounts of ATP 

Additional Enzymes Are Required for Oxidation of Unsaturated Fatty Acids in Mitochondria 

Polyunsaturated fatty acids are also degraded by [3 oxidation, but the process requires enoyl-CoA isomerase and an additional enzyme, 2,4-dienoyl-CoA reductase (fig. 18.6). For example, the degradation of linoleoyl-CoA (18 2A9-12) begins, like that of oleoyl-CoA, with three rounds of /3 oxidation and results in a A3-cis unsaturated fatty acyl-CoA that is not a substrate for acyl-CoA dehydrogenase. Isomerization of the double bond to the A2-trans position by enoyl-CoA isomerase allows the resumption of 

Unsaturated fatty acids such as oleoyl-CoA can also be degraded to acetyl-CoA in mitochondria. Three cycles of /3 oxidation result in an acyl-CoA (A3-cis-dodecenoyl-CoA) that is not a substrate for acyl-CoA dehydrogenase. This problem is circumvented by isomerization of the double bond to the t -tmns position by enoyl-CoA isomerase. Complete oxidation of the remainder of the molecule by the enzymes of f3 oxidation is now possible. 

Polyunsaturated fatty acids such as linoleoyl-CoA are also oxidized in the mitochondria. In addition to the enzymes of oxidation and enoyl-CoA isomerase, the process requires 2,4-dienoyl-CoA reductase. 

---

Fatty Acid Oxidation Yields Large Amounts of ATP Additional Enzymes Are Required for Oxidation of Unsaturated Fatty Acids in Mitochondria Ketone Bodies Formed in the Liver Are Used for Energy in Other Tissues Summary of Fatty Acid Degradation Biosynthesis of Saturated Fatty Acids... 

---