Carbohydrate core
Routes that capture, store, release and repartition six-carbon sugars, with glycolysis as a central exchange rather than an isolated tube.
Carbohydrate metabolism is best read as a set of reversible exchanges interrupted by strategically directed transformations. Glucose 6-phosphate sits near storage, oxidation and biosynthetic branches, so its meaning depends on which enzyme, compartment and energetic state are in view.
The pentose phosphate pathway is not simply an alternate route to glycolysis. Its oxidative arm changes the NADPH pool, while its non-oxidative carbon rearrangements connect sugars of different lengths to ribose and glycolytic intermediates.
Ideas to carry into the map
- Storage, oxidation and biosynthesis meet at sugar phosphates.
- Carbon rearrangement and redox output are separate dimensions.
- Compartment and enzyme identity determine direction.
Pathways in this field note
Cytosolic conversion of glucose-derived carbon to pyruvate, coupled to adenine-nucleotide and nicotinamide chemistry.
Formation of glucose from non-carbohydrate carbon with compartment-specific bypasses of strongly directed glycolytic steps.
Oxidative and non-oxidative reactions that connect glucose 6-phosphate to NADPH production and ribose-phosphate pools.
Assembly and mobilization of a branched glucose polymer, including its chemically distinct terminal reactions.