All systems ↗Fast routing
Glycolysis, the pentose-phosphate pathway, lactate exchange, fatty-acid synthesis, and many amino-acid reactions share carbon and redox cofactors.
SYSTEMS / CELLULAR ENERGY · MITOCHONDRIA
Fuel becomes
work, heat & renewal.
Follow carbon, electrons, oxygen, and phosphate across cytosol and mitochondria. See how cells change fuel use with feeding, fasting, exercise, hypoxia, and stress—without reducing metabolism to a single pathway or “ATP score.”
Qualitative educational model · not diagnosis, performance testing, supplement advice, or a personal mitochondrial assessment Evidence reviewed 25 Aug 2026
INTERACTIVE METABOLIC FLEXIBILITY ATLAS
One cell.
Five contexts.
Pathways overlap continuously. The selected state changes relative flux, substrate choice, signaling, and constraints; it does not switch whole pathways absolutely on or off.
READY
Storage and oxidation share incoming fuel
Press play or select a stage.
TRANSCRIPT Narration follows the visible stage detail.
Arrows show a teaching sequence, not isolated reactions. Tissue, intensity, duration, training, hormones, substrate delivery, temperature, medicines, and health state all alter the response.
QUALITATIVE ENERGY-DEMAND EXPLORER
Change demand.
See the constraint.
Compare pathway involvement as ATP turnover, oxygen availability, fuel context, and duration change. Outputs are directions—not ATP concentrations, calories burned, fitness, lactate thresholds, or clinical predictions.
RELATIVE PATHWAY INVOLVEMENTResting · usual oxygen
Interpretation boundary A “higher” label means greater relative involvement versus the default resting context. It does not mean healthier, more efficient, or pathologic. Lactate is a normal circulating fuel and redox shuttle—not merely a waste product.
CELLULAR COMPARTMENT MAP
Location controls
what can happen.
Metabolism is organized by membranes, transporters, enzymes, and tissue expression. “The cell” and “the mitochondrion” are not single well-mixed containers.
Carbon oxidation
Pyruvate dehydrogenase, the citric-acid cycle, beta-oxidation, and selected amino-acid reactions generate reduced electron carriers.
Electrochemical coupling
The respiratory chain builds proton motive force; ATP synthase couples its return to ATP formation. Transport costs and proton leak matter.
Sensing and renewal
mTORC1 integrates nutrient and growth signals near lysosomes; autophagy, ER signaling, fission, fusion, and mitophagy help maintain the network.
COMMON MODELING ERRORS
Keep the nuance.
- ATP is a turnover currency, not stored electricity. Cells continually regenerate and consume it.
- Lactate is not synonymous with oxygen absence. It is produced and consumed under many oxygenated conditions.
- ROS are not simply toxins. Controlled reactive species signal; excess or misplaced production can damage.
- Mitochondrial number is not metabolic health. Capacity, coupling, quality control, tissue context, and demand all matter.
- Metabolic flexibility is not a moral score. Fuel selection reflects context; impaired switching can be cause, consequence, or correlate of disease.
- Autophagy is not an instant “cleanse.” It is regulated cellular recycling, not a consumer-facing detox meter.
SOURCE REGISTER
Trace the model.
Foundational biochemistry resources support pathway structure; peer-reviewed reviews support state integration, redox, and nutrient-sensing nuance. Mechanistic sources do not prove a personal clinical outcome.