OXIDATIVE METABOLISM OF CARBOHYDRATES IN INSECTS: III. HEXOSE MONOPHOSPHATE OXIDATIVE CYCLE IN THE HOUSEFLY, MUSCA DOMESTICA L
| Autor: | Chefurka W |
|---|---|
| Rok vydání: | 1958 |
| Předmět: |
chemistry.chemical_classification
Insecta Cell Respiration Dehydrogenase General Medicine Metabolism Isomerase Pentose phosphate pathway Transketolase Biology Phosphate chemistry.chemical_compound Sedoheptulose Biochemistry chemistry Houseflies Animals Hexose Hexosephosphates Oxidation-Reduction Hexoses |
| Zdroj: | Canadian Journal of Biochemistry and Physiology. 36:83-102 |
| ISSN: | 0576-5544 |
| DOI: | 10.1139/y58-012 |
| Popis: | The component reactions of the hexose monophosphate oxidative pathway have been studied in adult houseflies. It has been shown that houseflies possess an active glucose-6-phosphate dehydrogenase, 6-phosphogluconolactonase, 6-phosphogluconic dehydrogenase, phosphopentose isomerase, phosphoketopentose epimerase, transketolase, and transaldolase.The cycle consists of five main steps: (a) a two-step oxidation of glucose-6-phosphate to ribulose-5-phosphate and CO2; (b) isomerization of ribulose-5-phosphate to ribose-5-phosphate; (c) epimerization of ribulose-5-phosphate to xylulose-5-phosphate; (d) conversion of pentose phosphate to sedoheptulose phosphate and triose phosphate; (e) conversion of sedoheptulose phosphate to hexose phosphate.Balance studies indicate that 2 moles of pentose phosphate are utilized for the formation of 1 mole of heptulose phosphate. However, this stoichiometry is attained after a lag period, suggesting the formation of a transient intermediate. Because the lag was eliminated by the addition of hydroxypyruvate, it is suggested that the lag was due to the time required for the combination of a C2fragment with an appropriate aldehyde acceptor. |
| Databáze: | OpenAIRE |
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