Glucose monophosphate

Coates, S. A., and ap Rees, T. 1994. Metabolism of glucose monophosphates by leucoplasts and amyloplasts from soybean suspension cultures. Phytochemistry 35, 881-883. 

The effects of salt stress have been investigated in perfused maize cells with and Na NMR. In cells exposed to salt stress there was a significant increase in vacuolar pH whilst the cytoplasmic pH remained constant. In concentrations of up to approximately 300 mM Na, vacuolar pH and the rate of Na" uptake were dependent on the extracellular concentration above 300 mM, vacuolar pH and Na" uptake were independent of the extracellular concentration. Na uptake into the cell was accompanied by a rapid increase in vacuolar Pi, broadening of the P resonances and a reduction in glucose monophosphate and UDPG. ... 

Triose, tetrose, and pentose phosphates enriched with C have been prepared by the Kiliani-Fischer reaction on the terminal phosphates of the next lower aldose. The mixed nitriles were separated on Dowex 1-X8 resin and reduced with hydrogen over Pd-BaS04. The synthesis of D-glucose 2-phosphate by phosphorylation of l,3,4,6-tetra-0-acetyl-j3-D-glucopyranosyl chloride, itself prepared by 2 1 acetyl migration, has been reported. Rates of phosphate hydrolysis in 0.25 M sulphuric acid and in 0.25 M sodium hydroxide were measured for D-glucose monophosphates in the former the order was 1-phosphate > 2-phosphate > 3-phosphate > 6-phosphate while in the latter it was 3-phosphate > 6-phosphate > 2-phosphate > 1-phosphate. ... 

Glucose monophosphate has five possible isomeric forms with the -OPO3H groups being attached to C Cj, C3, C4 or Cg. Glucose diphosphate has 10 possible isomers with the phosphate groups attached to 1 2,1 3.1 4,1 6, 2 3, 2 4, 2 6, 3 4, 3 6 or 4 6 carbon atoms. Known fructose phosphates are 1 mono, 6 mono, 1 6 di and 2 6 di. 

To introduce a phosphate grouping into an organic compound for example, glucose monophosphate produced by the action of phosphorylase. 

On treatment with acid, glucose is liberated first, followed by a molecule of inorganic phosphate. The intermediate, uridine diphosphate, has been isolated. Uridine-5 -pho8phate is quite stable to acid. In alkali, the pyrophosphate linkage is cleaved, liberating the nucleotide plus a cyclic glucose monophosphate in which the phosphate is esterified both at Ci and another carbon atom, probably Cj. ... 

Glucose Monophosphates.—A crude monophosphate (Robison s ester) has been obtained by the action of yeast juice on glucose or fructose. It is a mixture of fructose monophosphate (Neuberg s ester) and glucopyranose-6-phosphoric acid (Embden s ester). The two esters have been separated by fractional crystallisation of their brucine salts. A glucopyranose-1-monophosphate (Cori s ester) is obtained by the action of phosphate on minced muscle. 

Phosphate Esters. The phosphorylation of sucrose using sodium metaphosphate has been reported (78). Lyoptulization of a sodium metaphosphate solution of sucrose at pH 5 for 20 hours followed by storage at 80°C for five days produced a mixture of sucrose monophosphates. These products were isolated by preparative hplc, with a calculated yield of 27% based on all organic phosphate as sucrose monoesters. Small proportions of glucose and fmctose were also formed. 

Cells require a constant supply of N/ X)PH for reductive reactions vital to biosynthetic purposes. Much of this requirement is met by a glucose-based metabolic sequence variously called the pentose phosphate pathway, the hexose monophosphate shunt, or the phosphogluconate pathway. In addition to providing N/VDPH for biosynthetic processes, this pathway produces ribos 5-phosphate, which is essential for nucleic acid synthesis. Several metabolites of the pentose phosphate pathway can also be shuttled into glycolysis. 

Draw the structure of cyclic adenosine monophosphate (cAMP), a messenger involved in the regulation of glucose production in the body. Cyclic AMP has a phosphate ring connecting the 3 and 5 hydroxyl groups on adenosine. 

False. D-gluconolactone is produced directly from glucose via glucose oxidase. 6-phosphogluconolactone is an intermediate in the hexose monophosphate pathway. 

Figure 47-7. Pathway of biosynthesis of dolichol-P-P-oligosaccharide. The specific linkages formed are indicated in Figure 47-8. Note that the first five internal mannose residues are donated by GDP-mannose, whereas the more external mannose residues and the glucose residues are donated by dolichol-P-mannose and dolichol-P-glucose. (UDP, uridine diphosphate Dol, dolichol P, phosphate UMP, uridine monophosphate GDP, guanosine diphosphate M, mannose G, glucose.)...

Mature red blood cells do not have nuclei, mitochondria, or microsomes therefore red blood cell function is supported through the most primitive and universal pathway. Glucose, the main metabolic substrate of red blood cells, is metabolized via two major pathways the Embden-Meyerhof glycolytic pathway and the hex-ose monophosphate pathway (Fig. 1). Under normal circumstances, about 90% of the glucose entering the red blood cell is metabolized by the glycolytic pathway and 10% by the hexose monophosphate pathway. 

The oxidative pathway for the metabolism of D-glucose 6-phosphate (XLV), distinctive from the glycolytic, Embden-Meyerhof route (see p. 200) and known as the hexose monophosphate shunt, was suggested by certain experiments of Warburg,200 Gerischer,207 Lipmann,208 and Dickens209... 

A single enzyme, inositol monophosphatase, leads to loss of the remaining phosphate and the regeneration of free inositol. This enzyme exhibits similar affinities for all five of the equatorial inositol monophosphate hydroxyls. Inositol 2-phosphate, which is not produced in this degra-dative pathway, is a poor substrate, a property that is probably attributable to its axial configuration. The enzyme is inhibited by Li+ in an uncompetitive manner i.e. the degree of inhibition is a function of substrate concentration. The putative link between the ability of Li+ to interfere with phosphoinositide turnover and its therapeutic efficacy in the treatment of bipolar disorders is discussed in Box 20-1 and Chapter 55. It should be noted that unlike most other tissues, brain can synthesize inositol de novo by the action of inositol monophosphate synthase, which cyclizes glucose 6-phosphate to form I(3)P. The enzyme has been localized immunohistochemically to the brain vasculature. 

Under basal conditions 5% of brain glucose is metabolized via the pentose phosphate shunt (PPS), also termed the hexose monophosphate pathway [66], a pathway active in both neurons and astrocytes. The PPS has... 

EAAT excitatory amino acid transporter GLUT glucose transporter guanosine 5 -monophosphate... 

C5a and C5a des Arg stimulate aerobic glycolysis, hexose monophosphate shunt activity, glucose uptake and the respiratory burst of human neutrophils. All of these processes are stimulated in neutrophil suspensions incubated in the absence of cytochalasin B, but the responses are considerably enhanced if this inhibitor of microtubule assembly is present. Stimulated rates of oxidative metabolism are maximal within 2 min of addition of peptides, with half-maximal responses obtained at 30-60 nM C5a and 1-3 pM C5a des Arg. 

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