Which molecule produces the largest amount of ATP upon complete oxidation?

Which molecule produces the largest amount of ATP upon complete oxidation?

• A. One molecule of a 6-carbon saturated fatty acid
• B. Two molecules of glucose
• C. One molecule of a 12-carbon saturated fatty acid
• D. Four molecules of pyruvate

Answer: (C)

The correct choice is based on the understanding of how different molecules are metabolized to produce ATP through cellular respiration and oxidative phosphorylation. A 12-carbon saturated fatty acid goes through a process called beta-oxidation, where it is broken down into acetyl-CoA units. Each acetyl-CoA can enter the citric acid cycle (Krebs cycle), leading to the generation of NADH and FADH2, which subsequently contribute to ATP production during oxidative phosphorylation. In terms of ATP yield, one molecule of a 12-carbon saturated fatty acid undergoes multiple cycles of beta-oxidation, ultimately generating several acetyl-CoA molecules. Each cycle of beta-oxidation produces one FADH2 and one NADH, both of which are electron carriers that generate additional ATP when they enter the electron transport chain. The complete oxidation of this fatty acid results in a higher ATP yield compared to glucose or other options provided. While glucose is a significant energy source and can produce a good amount of ATP, the total yield is generally lower when comparing the complete oxidation of fatty acids due to the greater number of carbons and the resulting number of acetyl-CoA molecules produced. Similarly, pyruvate, being a product of glycolysis,

The correct choice is based on the understanding of how different molecules are metabolized to produce ATP through cellular respiration and oxidative phosphorylation. A 12-carbon saturated fatty acid goes through a process called beta-oxidation, where it is broken down into acetyl-CoA units. Each acetyl-CoA can enter the citric acid cycle (Krebs cycle), leading to the generation of NADH and FADH2, which subsequently contribute to ATP production during oxidative phosphorylation.

In terms of ATP yield, one molecule of a 12-carbon saturated fatty acid undergoes multiple cycles of beta-oxidation, ultimately generating several acetyl-CoA molecules. Each cycle of beta-oxidation produces one FADH2 and one NADH, both of which are electron carriers that generate additional ATP when they enter the electron transport chain. The complete oxidation of this fatty acid results in a higher ATP yield compared to glucose or other options provided.

While glucose is a significant energy source and can produce a good amount of ATP, the total yield is generally lower when comparing the complete oxidation of fatty acids due to the greater number of carbons and the resulting number of acetyl-CoA molecules produced. Similarly, pyruvate, being a product of glycolysis,