α-ketoglutarate undergoes simultaneous dehydrogenation and decarboxylation in the presence of enzyme α-ketoglutarate dehydrogenase complex. This enzyme complex contains TPP, Lipoic Acid, Mg2+, and trans-succinylase. NAD+ and CoA are required. The products formed are 4-carbon compound succinyl CoA, NADH2, and CO2.