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Podsumowanie reakcji szlaku pentozofosforanowego

2    ksylulozo-5 fosforan + rybozo-5-fosforan + t

2 ffuktozo-6-fosforan + aldehyd 3-fosfoglicerynow}

3    rybozo-5-fosforan _Ą ►    2 fruktozo-6-fosforan + aldehyd 3-fosfoglicerynowA

TABLE 20.3 Pentose phosphate pathway

Reaction

Oxidative phasc

Glucose 6-phosphate 4- NADP^f

Enzyme

6-pho$phoglucono-S-lactone 4- NADPH + H⁺ Glucose 6-phosphate dehydrogenase

Lactonase

6-Phosphogluconate dehydrogenase

Phosphopentose isomerase Phosphopentose epimerase Transketolase

Transaldolase

Transketolase

6-Phosphoglucono-S-lactone 4- H2O-> 6-phosphogluconate 4- H ⁺

6-Phosphogluconate 4- NADP ^ł -> ribulose 5-phosphate 4- CO2 + NADPH

ribose 5-phosphate

Nonoxidative Phase Ribulose 5-phosphate

Ribulose 5-phosphate s=± xylu!ose 5-phosphate Xylulose 5-phosphate 4- ribose 5-phosphate

sedoheptulose 7-phosphate 4- glyceraldehyde 3-phosphate

Sedoheptulose 7-phosphate 4- glyceraldehyde 3-phosphate v *

fructose 6-phosphate 4- erythrose 4-phosphate

Xylulo$e 5-phosphate 4- erythrose 4-phosphate ;■—*

fructose 6-phosphate 4- glyceraldehyde 3-phosphate

Nadmiar rybozo-5-fosforanu wytworzonego w szlaku pentozofosforanowym może być całkowicie przekształcony w metabolity pośrednie glikolizy.