Fatty Acid Breakdown Occurs in Blocks of Two Carbon Atoms

Fatty Acid Breakdown Occurs in Blocks of Two Carbon Atoms 

Recall that fatty acid chains nearly always contain an even number of carbon atoms (see chapter 17). Investigations into the mechanisms of fatty acid catabolism began around the turn of the century when Fritz Knoop reported experiments that indicated fatty acids were degraded by removal of two carbons at a time. The data indicated that carbon 3 of a fatty acid was oxidized with subsequent cleavage between carbons 2 and 3. 

Carbon 2 is also known as the alpha (a) carbon and carbon 3 as the beta (/3) carbon. Hence the term (3 oxidation was coined. 

The Oxidation of Saturated Fatty Acids Occurs in the Mitochondria 

We now explore the remarkable process by which a long-chain saturated fatty acid is converted into two-carbon units (acetate), which can be oxidized to C02 and H20 via the tricarboxylic acid cycle and the electron-transport chain. Fatty acids that enter cells are activated to their CoA derivatives by the enzyme acyl-CoA ligase and transported into the mitochondria for /3 oxidation as we discuss later in this chapter. 

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Fatty Acids Originate from Three Sources Diet, Adipocytes, and de novo Synthesis Fatty Acid Breakdown Occurs in Blocks of Two Carbon Atoms... 

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