Which glycolytic pathway yields two ATP and two NADH per glucose?

Which glycolytic pathway yields two ATP and two NADH per glucose?

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

Answer: (C)

Glycolysis in its classic form, the Embden-Meyerhof pathway, breaks one glucose into two pyruvate molecules in the cytosol and produces energy by substrate-level phosphorylation. You invest two ATP at the start to activate glucose, then later steps generate four ATP, giving a net gain of two ATP. In addition, two molecules of NAD+ are reduced to NADH during the oxidation steps. So, per glucose, the pathway yields two ATP and two NADH. Other routes either don’t occur as the standard glycolytic sequence or have different energy yields. The Entner-Doudoroff pathway produces less ATP per glucose, the Krebs cycle is a later step that happens after glycolysis and provides different electron carriers, and fermentation is a downstream process that regenerates NAD+ after glycolysis rather than defining glycolysis itself.

Glycolysis in its classic form, the Embden-Meyerhof pathway, breaks one glucose into two pyruvate molecules in the cytosol and produces energy by substrate-level phosphorylation. You invest two ATP at the start to activate glucose, then later steps generate four ATP, giving a net gain of two ATP. In addition, two molecules of NAD+ are reduced to NADH during the oxidation steps. So, per glucose, the pathway yields two ATP and two NADH.

Other routes either don’t occur as the standard glycolytic sequence or have different energy yields. The Entner-Doudoroff pathway produces less ATP per glucose, the Krebs cycle is a later step that happens after glycolysis and provides different electron carriers, and fermentation is a downstream process that regenerates NAD+ after glycolysis rather than defining glycolysis itself.