Which process is aerobic and converts pyruvate into CO2 and H2O, yielding ATP?

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Multiple Choice

Which process is aerobic and converts pyruvate into CO2 and H2O, yielding ATP?

Explanation:
The concept being tested is how aerobic cellular metabolism fully oxidizes pyruvate to carbon dioxide and water while generating ATP. In the presence of oxygen, pyruvate from glycolysis is transported into mitochondria and converted to acetyl-CoA by the pyruvate dehydrogenase complex, releasing CO2 and generating NADH. Acetyl-CoA then enters the citric acid cycle, producing more CO2 along with NADH and FADH2. Those electron carriers feed the electron transport chain, where oxygen is the final electron acceptor; the resulting proton motive force drives ATP synthase to make ATP, and water forms when oxygen pairs with electrons and protons. This whole sequence—pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation—constitutes cellular respiration and yields CO2 and H2O with a large amount of ATP. Glycolysis occurs first and yields a small amount of ATP and pyruvate, but by itself it does not convert pyruvate into CO2 and H2O. Fermentation can happen without oxygen and does not fully oxidize pyruvate to CO2 and H2O. Photosynthesis uses light energy to build sugars and is not the process that converts pyruvate to CO2 and H2O.

The concept being tested is how aerobic cellular metabolism fully oxidizes pyruvate to carbon dioxide and water while generating ATP. In the presence of oxygen, pyruvate from glycolysis is transported into mitochondria and converted to acetyl-CoA by the pyruvate dehydrogenase complex, releasing CO2 and generating NADH. Acetyl-CoA then enters the citric acid cycle, producing more CO2 along with NADH and FADH2. Those electron carriers feed the electron transport chain, where oxygen is the final electron acceptor; the resulting proton motive force drives ATP synthase to make ATP, and water forms when oxygen pairs with electrons and protons. This whole sequence—pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation—constitutes cellular respiration and yields CO2 and H2O with a large amount of ATP.

Glycolysis occurs first and yields a small amount of ATP and pyruvate, but by itself it does not convert pyruvate into CO2 and H2O. Fermentation can happen without oxygen and does not fully oxidize pyruvate to CO2 and H2O. Photosynthesis uses light energy to build sugars and is not the process that converts pyruvate to CO2 and H2O.

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