Question

We have examined the total ATP, $\mathrm{NADH}$, and ${\mathrm{FADH}}_2$ production in the Krebs cycle for each molecule of glucose coming through Embden-Meyerhof glycolysis. How many of each of these molecules would be produced if the Entner-Doudoroff pathway were used instead of Embden-Meyerhof glycolysis?

Short answer

If the Entner-Doudoroff pathway is used instead of the Embden-Meyerhof pathway, the total production would be 3 ATP, 7 NADH, and 2 FADH2 for each glucose molecule.

Step-by-step solution

Glycolysis via the Entner-Doudoroff pathway

For each molecule of glucose that goes through the Entner-Doudoroff pathway, one molecule of ATP, one molecule of NADH, and zero molecules of FADH2 are produced.

Krebs Cycle

Each molecule of pyruvate in the Krebs cycle generates 1 ATP, 3 NADH, and 1 FADH2. Thus, for the 2 pyruvates produced from one glucose molecule in the Entner-Doudoroff pathway, there will be 2 ATPs, 6 NADHs, and 2 FADH2s.

Total ATP, NADH, and FADH2

Adding the products from the Entner-Doudoroff glycolysis and the Krebs cycle gives the total ATP, NADH, and FADH2 produced. For ATP, 1 (from glycolysis) + 2 (from the Krebs cycle) = 3 ATP. For NADH, 1 (from glycolysis) + 6 (from the Krebs cycle) = 7 NADH. For FADH2, there is no contribution from glycolysis, so there are 2 FADH2 from the Krebs cycle.