Table 2.
Metabolic energy yields from different substrates. It is assumed that mitochondria produces 2.5 ATP/NADH and FADH2 produces 1.5 ATP. GTP is made in the substrate level phosphorylation via succinyl CoA synthetase.
| Compound | Pathway | ATP yield | Comments |
|---|---|---|---|
| Glycogen | Glycogenolysis + lactic fermentation | 3/glucose subunit | Phosphorolysis generates G1P |
| Glucose | Lactic fermentation | 2/glucose subunit | |
| Glycolysis | 2 + 3 | 3 for shuttles to respiring mitochondria | |
| Fructose | Fructose cleavage to lactate | 2 | Fructokinase + glyceraldehyde kinase |
| Galactose | Lactic fermentation | 2 | |
| Glycolysis | 2 + 3 | 3 for shuttles to respiring mitochondria | |
| Pyruvate | Krebs Cycle | 11.5 ATP + 1 GTP | |
| Lactate | Krebs Cycle | 14 ATP + 1 GTP | NADH produced reoxidized via shuttle |
| Acetate | Krebs Cycle | 8 ATP + 1 GTP | 1 ATP used for activation of acetate to AcCoA |
| Palmitate | Beta-oxidation/Krebs Cycle | 106 ATP + 7 GTP | |
| Glutamine- > OAA | Krebs Cycle | 6.5 ATP + 1 GTP | Transamination of Glu via GOT |
| 9 ATP + 1 GTP | Oxidative deamination of Glu via glutamate dehydrogenase |