Biochemical and transport reactions in current starch degradation model. The carbon flux in the starch degradation pathway from solubilised starch in the chloroplast stroma to hexose phosphates in the cytosol has been schematically represented in this figure. The pathway consists of seven enzyme catalyzed reactions and two transport reactions. The different types of species in this figure have been color-coded. The metabolite species are shown in black; enzymes are in red and transporters in orange; and, irreversible and reversible reactions are shown as blue and purple arrows, respectively. The dashed arrow showing maltotriose formation from linear glucans reflects that this reaction is substoichiometric, occurring only once per odd-length chain.