Glucose-6-phosphate distribution

What would be the distribution of carbon from positions 1, 3, and 6 of glucose after one pass through the pentose phosphate... 

C5. Cohen, R. B., The histochemical distribution and metabolic significance of glucose-6-phosphate dehydrogenase activity, glycogen and lipid in the stimulated adrenal cortex. Endrocrinology 68, 710-715 (1961). 

This pathway is variously known as the pentose phosphate, hexose monophosphate or phosphogluconate pathway, cycle or shunt. Although the pentose phosphate pathway achieves oxidation of glucose, this is not its function, as indicated by the distribution of the pathway in different tissues. Only one of the carbons is released as CO2, the key products are NADPH and ribose 5-phosphate, both of which are important for nucleotide phosphate formation and hence for synthesis of nucleic acids (Chapter 20). The... 

This enzyme [EC 5.3.1.1], also known as triosephosphate mutase (TIM) and phosphotriose isomerase, catalyzes the interconversion of D-glyceraldehyde 3-phosphate and dihydroxyacetone phosphate (fUPAC glycerone phosphate). As pointed out by Rose, this enzyme is chiefly responsible for the largely symmetrical conversion of the two three-carbon segments of glucose to lactate and for the nearly uniform distribution of from pyruvate in the glucosyl units of hver glycogen. The... 

Fig. 2. Experimental design of a C tracer experiment for the determination of the flux partitioning ratio between pentose phosphate pathway and glycolysis ( ppp) C label distribution from l- C glucose through the network with C atoms (black) and C atoms (white)...

Hayami and his coworkers have studied the mechanism of formation of acetol and pyruvic acid from D-glucose- -14C, -6-14C, and -3,4-14C2, reacting in a concentrated, phosphate buffer solution.148-151 Their data supported the supposition that the products are formed from pyruvaldehyde by way of a Cannizarro reaction. As in the formation of lactic acid, the pyruvaldehyde can be formed either from the reducing or the nonreducing end of the D-glucose molecule, and the distribution of radioactivity in the pyruvic acid and acetol... 

FIGURE 23-13 Metabolic pathways for glucose 6-phosphate in the liver. Here and in Figures 23-14 and 23-15, anabolic pathways are shown leading upward, catabolic pathways leading downward, and distribution to other organs horizontally. The numbered processes in each figure are described in the text. 

When fructose 6-phosphate containing both 2H and 14C in the 1 position was isomerized in the presence of a large amount of nonlabeled fructose 6-phosphate, the product glucose 6-phosphate contained not only 14C but also 2H, and the distribution indicated that the 2H had been transferred from the C-l position into the C-2 position.123 It was concluded that in over half the... 

Deficiency of the first enzyme of the pentose phosphate pathway, glucose 6-phosphate dehydrogenase, is widespread.11 Its geographical distribution suggests that, like the sickle-cell trait, it confers some resistance to malaria. A partial deficiency of 6-phosphogluconolactonase (Eq. 17-12, step b) has also been detected within a family and may have contributed to the observed hemolytic anemia.1... 

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