Answer
Acetyl CoA enters in kreb cycle by condensing with oxaloacetate. Oxaloacetate concentration consider to be limiting for Kreb's cycle. When there is active gluconeogenesis in liver. Oxaloacetate diverted to form glucose via PEP. Thus oxaloacetate is not available to combine with acetyl CoA, resulting in increase in acetyl CoA. Increased acetyl CoA activates pyruvate carboxylase, which converts pyruvate into oxaloacetate.
Work Step by Step
Acetyl CoA enters in kreb cycle by condensing with oxaloacetate. Oxaloacetate concentration consider to be limiting for Kreb's cycle. When there is active gluconeogenesis in liver. Oxaloacetate diverted to form glucose via PEP. Thus oxaloacetate is not available to combine with acetyl CoA, resulting in increase in acetyl CoA. Increased acetyl CoA activates pyruvate carboxylase, which converts pyruvate into oxaloacetate.
