Question

in gluconeogenesis, the CO₂ added to pyruvate in the pyruvate carboxylase step is the same molecule that is lost in the phosphoenolpyruvate (pep) carboxykinase reaction. what is the benefit of this type of carboxylation-decarboxylation sequence?

Answer 1

The carboxylation-decarboxylation sequence in gluconeogenesis benefits carbon conservation during glucose synthesis.

Step-by-step explanation:

The benefit of the carboxylation-decarboxylation sequence in gluconeogenesis is that it allows for the conservation of carbon atoms. In the pyruvate carboxylase step, a carboxyl group (CO₂) is added to pyruvate, forming oxaloacetate.

This oxaloacetate is then decarboxylated in the phosphoenolpyruvate carboxykinase step, ultimately producing phosphoenolpyruvate (PEP). Since the CO₂ added in the first step is the same molecule lost in the second step, no carbon atoms are wasted, resulting in efficient carbon conservation during glucose synthesis.