Enter your Number of NADH Molecules, Number of FADH2 Molecules, their respective ATP yield values, and optional Substrate-Level ATP to calculate your Total ATP Produced — plus a full breakdown of ATP from NADH, ATP from FADH2, Total Electrons Transferred, and Energy Conversion Efficiency across the Electron Transport Chain.
Total ATP Produced
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ATP from NADH
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ATP from FADH2
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Total Electrons Transferred
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Energy Conversion Efficiency
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The electron transport chain uses energy from electron transfers to pump protons across the inner mitochondrial membrane, creating a gradient that drives ATP synthase to produce ATP through chemiosmosis.
NADH enters the electron transport chain at Complex I, while FADH2 enters at Complex II. NADH passes through more proton-pumping complexes, generating more ATP per molecule.
Theoretical maximum is 3 ATP per NADH and 2 per FADH2, but actual yields are typically 2.5 and 1.5 respectively due to energy costs of transport and other cellular processes.
NADH is produced in glycolysis, pyruvate oxidation, and the citric acid cycle. FADH2 is primarily produced in the citric acid cycle and fatty acid oxidation.
Without oxygen as the final electron acceptor, the electron transport chain stops functioning, and cells must rely on anaerobic processes like fermentation for ATP production.
Complex I pumps 4 protons, Complex III pumps 4 protons, and Complex IV pumps 2 protons per electron pair, totaling 10 protons for NADH oxidation.