Decarboxylation reactions that produce carbon dioxide when a carboxylate group is removed are referred to as oxidative decarboxylation reactions.
They frequently take place in biological systems; the citric acid cycle is a good example of this.
This kind of reaction most likely got its start at the beginning of life.
No, oxidative decarboxylation is generally an irreversible step.
The carboxyl group is removed from pyruvate as a molecule of CO2 and the two remaining carbons become the acetyl group of Acetyl-CoA.
Oxidative decarboxylation of pyruvate is one of the significant steps of cellular respiration, which links glycolysis to the Krebs cycle.
It occurs in the mitochondria, where pyruvate (3C), which is the end product of glycolysis is decarboxylated to produce acetyl CoA (2C) by the enzyme pyruvate dehydrogenase.
Acetyl CoA enters the Krebs cycle and carbon dioxide is released in the process.