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In stage 3 of fatty acid synthesis, what happens to acetoacetyl ACP?

User Jmarceli
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1 Answer

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Final answer:

During fatty acid synthesis, acetoacetyl ACP is reduced, dehydrated, and further reduced to form a saturated acyl-S-ACP, extending the fatty acid chain, and this process repeats to eventually yield palmitoyl-ACP.

Step-by-step explanation:

In stage 3 of fatty acid synthesis, acetoacetyl ACP undergoes a series of reactions to be converted into a longer fatty acid chain. The process begins with the reduction of acetoacetyl-S-ACP to 3-hydroxyacyl-S-ACP by the enzyme 3-ketoacyl-ACP reductase, which uses NADPH as an electron donor

Then, 3-hydroxyacyl-S-ACP is dehydrated by 3-hydroxyacyl-ACP dehydratase to yield trans-∆²-enoyl-S-ACP. In the final reaction of this cycle, the enoyl-S-ACP is further reduced by enoyl-ACP reductase, again utilizing NADPH, to form a saturated acyl-S-ACP.

This process extends the fatty acid chain by two carbon atoms and is repeated until a 16-carbon palmitoyl-ACP is formed, at which point the fatty acid is released from ACP.

During stage 3 of fatty acid synthesis, acetoacetyl ACP is converted into acetoacetyl-S-ACP through condensation with malonyl-S-ACP. This condensation reaction is catalyzed by the enzyme 3-ketoacyl synthase.

The acetoacetyl-S-ACP is then further modified in subsequent reactions to form longer fatty acid chains

User Ro
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