[swwal]

why can't acetyl coa be used for gluconeogenesis unlike propionyl coa ?

 

[CleverFOX]

Because to do neoglucogenesis these products must enter Krebs cycle at some point,

Priopionyl CoA can enter Krebs cycle after being carboxylated to form Succinyl CoA but Acetyl CoA cannot enter Krebs cycle will never be able to form oxaloacetate and reverse through glycolysis pathway so it will never be able to form glucose

 

[swwal]

Because to do neoglucogenesis these products must enter Krebs cycle at some point,

Priopionyl CoA can enter Krebs cycle after being carboxylated to form Succinyl CoA but Acetyl CoA cannot enter Krebs cycle will never be able to form oxaloacetate and reverse through glycolysis pathway so it will never be able to form glucose

Thanks bro but I'm more confused now
what do u mean by "oxaloacetate and reverse through glycolysis pathway"

 

[CleverFOX]

Thanks bro but I'm more confused now
what do u mean by "oxaloacetate and reverse through glycolysis pathway"

After Propionyl CoA enters Krebs Cycle at Succinyl CoA Step then Succinyl CoA goes through Krebs Cycle to form "Oxaloacetate" from where we can start the pathway of neoglucogenesis!

Acteyl CoA can never enter Krebs Cycle at any other point than when it converts Oxaloacetate to Citric Acid.

See the oxaloacetate(inside mitochondria) it is where actually propionyl coa enters by forming succinyl coa and entering krebs cycle

So when I said cannot form oxaloacetate I meant cannot form oxaloacetate and enter neoglucogenesis!

 

[chaplin]

Also, the conversion of pyruvate to acetyl-CoA catalyzed by pyruvate dehydrogenase is irreversible. Therefore, the pyruvate dehydrogenase reaction cannot be used to convert acetyl-CoA to pyruvate or glucose.
The acetyl-CoA can be used for fatty acid / ketone body / cholesterole synthesis.