Glucose-6-phosphate, glycolysis

Besides being intermediaries of glycolysis, glucose-6-phosphate and fructose-6-phosphate are also essential substrates for secondary metabolism. In fact, both hexose-phosphates are needed to synthesize the polysaccharides used to construct the cell wall (Cabib et al. 1982). 

The biosynthesis of glycogen occurs from glucose-6-phosphate. As indicated earlier, this is one of several alternative fates of glucose-6-phosphate in addition to glycolysis. Glucose-6-phosphate via phosphoglucomutase and glucose-1,6-bisphosphate can be reversibly... 

Erythrocytes Transport of O2 1 Glycolysis, pentose phosphate pathway. No mitochondria and therefore no p-oxidation or citric acid cycle. Glucose Lactate 1 (Hemoglobin) ... 

A positive AG for this reaction conld also be achieved by a marked decrease in the concentration of glucose 6-phosphate. Why is this not feasible Glucose 6-phosphate is an important metabolic intermediate and is involved in several metabolic pathways (e.g. glycogen synthesis, glycolysis, pentose phosphate pathway). Lowering its concentration by the two orders of magnitude, which would be necessary, would markedly decrease the rates at which these important pathways could proceed. 

Glycolysis The process of converting glucose or glucose phosphate to pyruvate or lactate and producing ATP. This can occur in the absence of oxygen. 

Phosphorylation of Glucose In the first step of glycolysis, glucose is activated for subsequent reactions by its phosphorylation at C-6 to yield glucose 6-phosphate, with ATP as the phosphoryl donor ... 

In the remainder of the preparative phase of glycolysis, glucose-6-P is isomerized to fructose 6-phosphate (fructose-6-P), again phosphorylated, and subsequently cleaved into two 3-carbon fragments (Fig 22.5). The isomerization, which positions a keto group next to carbon 3, is essential for the subsequent cleavage of the bond between carbons 3 and 4. 

In the first stages of glycolysis, glucose is converted to two molecules of glyceraldehyde-3-phosphate. 

The reaction shown is the hydrolysis of a phosphoric anhydride the phosphate acceptor is water. In the first two reactions of glycolysis, the phosphate acceptors are —OH groups of glucose and fructose, respectively, and are used to form phosphoric esters of these monosaccharides. In two reactions of glycolysis, ADP is the phosphate acceptor and is converted to ATP. 

Scheme 1.2). Important intermediates for the secondary metabohsm are produced during glycolysis. Glucose, glucose-6-phosphate, and fructose-6-phosphate can be converted to other hexoses and pentoses that can be oligomerized and enter in the composition of heterosides. Additionally, fructose-6-phosphate connects the pentose... 

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