ENERGY

Central energy conversion

The mitochondrial and cytosolic interfaces that oxidize carbon, transfer reducing equivalents and couple electron movement to ATP formation.

Central energy conversion on the map

Cycle geometry is preserved because the pathway’s topology and carbon bookkeeping are clearer in a ring than in a generic graph.

The citric acid cycle is simultaneously an oxidative sequence and an exchange hub. Intermediates can leave for biosynthesis or enter from other routes, which is why anaplerotic and cataplerotic reactions belong beside the ring rather than in a footnote.

Respiratory electron transport and ATP formation are coupled through a membrane gradient, not through a direct chemical handoff from NADH to ATP. The compartment boundary is therefore a functional component of the system.

Ideas to carry into the map

The TCA cycle is an exchange hub.
A membrane gradient couples electron transport to ATP synthesis.
Displayed direction is not a measured rate.

Pathways in this field note

Pyruvate metabolismR-HSA-70268 · 31 represented events

Routes that move, reduce, oxidize or carboxylate pyruvate at the junction of carbohydrate, amino-acid and mitochondrial metabolism.

On the map Reactome source

Citric acid cycleR-HSA-71403 · 23 represented events

The mitochondrial reaction cycle that oxidizes acetyl units while exchanging intermediates with many biosynthetic routes.

On the map Reactome source

Respiratory electron transportR-HSA-611105 · 47 represented events

Transfer of electrons through mitochondrial respiratory complexes and mobile carriers.

On the map Reactome source

ATP by chemiosmotic couplingR-HSA-163210 · 3 represented events

ATP synthase chemistry driven by the electrochemical proton gradient across the inner mitochondrial membrane.

On the map Reactome source

All guide chapters