Metabolic pathway
Glycogenesis
Stores glucose as glycogen when there is a surplus. Activating each sugar with a nucleotide costs the equivalent of two high-energy bonds, and that price is what makes storing and releasing not the same road travelled in two directions.
- In
- Glucose 6-phosphate + UTP + Water
- Out
- Glycogen (glucose residue) + UDP + 2 Inorganic phosphate
- Location
- Cytosol
Fun facts
- Glycogen synthaseThe starting chain is made by glycogenin, a protein that attaches the first eight sugars to itself and then stays inside the granule, like the core of a ball of yarn.
Reactions
| # | Enzyme | ΔG°′ |
|---|---|---|
| 1 | PhosphoglucomutaseEC 5.4.2.2Glucose 6-phosphate ⇌ Glucose 1-phosphate | 7.3kJ/molendergonic |
| 2 | UDP-glucose pyrophosphorylaseEC 2.7.7.9Glucose 1-phosphate + UTP ⇌ UDP-glucose + Pyrophosphate | — |
| 3 | Inorganic pyrophosphataseEC 3.6.1.1 · irreversiblePyrophosphate + Water → 2 Inorganic phosphate | −19.2kJ/molexergonic |
| 4 | Glycogen synthaseEC 2.4.1.11 · irreversibleUDP-glucose → Glycogen (glucose residue) + UDP | −13.4kJ/molexergonic |
3 of 4 reactions with a documented ΔG.
Use Shift to select several
The data sheet includes the map. The logo goes at the bottom.
Sources
- Nelson, D. L. & Cox, M. M. (2021). Lehninger. Principios de bioquímica, 8.ª ed., ch. 15