Question

Oxidation of pyruvate to $CO_2$ ​and $H_2​O$ occurs through
A) Citric acid cycle
B) Tricarboxylic acid
C) Krebs cycle
D) All of the above.

Answer 1

Hint:Pyruvate is produced through glycolysis; two pyruvate molecules also possess a lot of recoverable energy at the end of glycolysis. Another step in collecting the residual energy in the form of ATP is oxidation of pyruvate, while no ATP is made directly through oxidation of pyruvate.

Complete answer
To answer this, we have to know about the process involved in the respiration process. Two component reactions include pyruvate oxidation: $NAD^+$ and a molecule named as coenzyme A. In a series of steps, pyruvate oxidation is updated. The acetyl group of acetyl CoA is bound to a four-carbon molecule of oxaloacetate in the TCA cycle to form a six-carbon citrate molecule. Citrate is oxidized through a series of steps, releasing two molecules of carbon dioxide for every acetyl group fed into the cycle. Three $NAD^+$ molecules are reduced to NADH in the method, one FAD molecule is reduced to $FADH_2$, and one ATP or GTP is formed by substrate-level phosphorylation depending on the type of cell. Since the TCA cycle's end product is also the first reactant, in the presence of appropriate reactants, the cycle normal operation.

In eukaryotes, the pyruvate oxidation step takes place in the matrix, the innermost compartment of mitochondria. In prokaryotes, it happens in the cytoplasm.

Hence, the correct answer is option (D) i.e, All of the above.

Note:The TCA cycle is essentially an energy producing process that has been developed to remove or transfer as much potential energy as can be used by the original energy source to form cells, ATP or the equivalent or an energized membrane. In the next step of cellular respiration, acetyl CoA serves as fuel for the citric acid cycle.