Which pathway yields one ATP and two NADPH per glucose, along with pyruvate production?

Which pathway yields one ATP and two NADPH per glucose, along with pyruvate production?

• A. Embden-Meyerhof pathway
• B. Krebs cycle
• C. Fermentation
• D. Entner-Doudoroff pathway

Answer: (D)

Entner-Doudoroff pathway is an alternate route for glucose breakdown used by some bacteria. It starts with glucose-6-phosphate being oxidized to 6-phosphogluconate, producing NADPH. That compound is then transformed into KDPG, which is cleaved into pyruvate and glyceraldehyde-3-phosphate. The glyceraldehyde-3-phosphate continues through the later glycolytic steps to pyruvate, yielding one ATP via substrate-level phosphorylation. Because one glucose molecule ends up as pyruvate from the split and the other as glycolytic intermediates that become pyruvate, you get two pyruvate molecules per glucose, with a net ATP gain of one and reducing power in the form of NADPH. This combination—pyruvate production with a modest ATP yield and NADPH generation—is characteristic of the Entner-Doudoroff pathway and distinguishes it from glycolysis, the Krebs cycle, and fermentation.

Entner-Doudoroff pathway is an alternate route for glucose breakdown used by some bacteria. It starts with glucose-6-phosphate being oxidized to 6-phosphogluconate, producing NADPH. That compound is then transformed into KDPG, which is cleaved into pyruvate and glyceraldehyde-3-phosphate. The glyceraldehyde-3-phosphate continues through the later glycolytic steps to pyruvate, yielding one ATP via substrate-level phosphorylation. Because one glucose molecule ends up as pyruvate from the split and the other as glycolytic intermediates that become pyruvate, you get two pyruvate molecules per glucose, with a net ATP gain of one and reducing power in the form of NADPH. This combination—pyruvate production with a modest ATP yield and NADPH generation—is characteristic of the Entner-Doudoroff pathway and distinguishes it from glycolysis, the Krebs cycle, and fermentation.