How many CO₂ released during one Krebs cycle, if acetyl CoA oxidise?

During one Krebs cycle (citric acid cycle or TCA cycle), if one molecule of acetyl-CoA is oxidized, two molecules of CO₂ are released.

Isocitrate to α-Ketoglutarate

Isocitrate, an intermediate in the citric acid cycle, is converted to α-Ketoglutarate in a reaction catalyzed by the enzyme isocitrate dehydrogenase. In this reaction, isocitrate undergoes oxidative decarboxylation, resulting in the release of one molecule of CO₂ and the formation of α-Ketoglutarate.

α-Ketoglutarate to Succinyl-CoA

 α-Ketoglutarate is then further metabolized to succinyl-CoA in a reaction catalyzed by the enzyme α-ketoglutarate dehydrogenase complex. This is another oxidative decarboxylation step that leads to the release of one molecule of CO₂ and the formation of succinyl-CoA