Final answer:
The energy released in the oxidative decarboxylation of pyruvate to acetyl-CoA is conserved through the creation of NADH, which carries high-energy electrons to the electron transport chain where they are used to generate ATP, thus storing the energy in a usable form for the cell.
Step-by-step explanation:
Energy Conservation in Oxidative Decarboxylation
The oxidative decarboxylation of pyruvate to acetyl-CoA involves the conversion of the three-carbon pyruvate molecule into a two-carbon acetyl CoA molecule, with the release of carbon dioxide (CO2). During this highly exergonic reaction, which occurs in the mitochondrial matrix, the enzyme pyruvate dehydrogenase removes one carbon from pyruvate, forming CO2, and reduces NAD+ to NADH which captures the energy released. The acetyl group is then transferred to coenzyme A (CoA) creating a high-energy thioester bond in Acetyl-S-CoA. The conservation of energy in animals and plants occurs through the reduction of NAD+ to NADH, which will enter the electron transport chain and subsequently be used in the formation of a large amount of ATP.
In aerobic conditions, NADH generated from this reaction is not immediately oxidized; instead, it is transported to the electron transport chain where oxygen will help catalyze the production of ATP from ADP. The synthesis of ATP in the mitochondrial redox reactions marks the conservation of energy initially released by the decarboxylation of pyruvate.