Phosphate blues

Turquoise Hydrated copper aluminum phosphate Blue 2.7... 

Phosphate blues can also form. When cis-PtCl2(NH3)2 and KH2P04 in water at pH 4.5 and 40 °C are exposed to air, a deep blue color develops over several days. The reaction proceeds faster if [Pt(NH3)2(H20)2](N03)2 is used as precursor. The isolated blue solids are weakly paramagnetic (0.5 0.2 BM per platinum atom) and give a complicated ESR spectrum with peaks centered at g = 1.9-2.4 and g = 4.29. The solids are insoluble in water and dissolve in alkali but with the loss of blue color.1653... 

Analytical Characters. — Chromous Salts. — (1.) Potash, a brown ppt. (3.) Ammonium hydroxid, greenish-white ppt. (3.) Alkaline sulflds, black ppt. (4.) Sodium phosphate, blue ppt. 

Rapeseed (Brassica campestris) oil blue indigo mfg. lndol-3-yl sodium phosphate blue pigment mfg. 

FIGURE 28 5 (a) Tube and (b) space filling models of a DNA double helix The carbohydrate-phosphate backbone is on the out side and can be roughly traced in (b) by the red oxygen atoms The blue atoms belong to the purine and pyrimidine bases and he on the inside The base pairing is more clearly seen in (a)... 

This experiment uses the molybdenum-blue method to determine the concentration of phosphate in a phosphate/sodium chloride mixture. Elow-injection analysis is used to increase the speed of analysis, allowing students to... 

Phosphatase Test. The phosphatase [9001-78-9] test is a chemical method for measuring the efficiency of pasteurization. AH raw milk contains phosphatase and the thermal resistance of this enzyme is greater than that of pathogens over the range of time and temperature of heat treatments recognized for proper pasteurization. Phosphatase tests are based on the principle that alkaline phosphatase is able, under proper conditions of temperature and pH, to Hberate phenol [108-95-2] from a disodium phenyl phosphate substrate. The amount of Hberated phenol, which is proportional to the amount of enzyme present, is determined by the reaction of Hberated phenol with 2,6-dichloroquinone chloroimide and colorimetric measurement of the indophenol blue formed. Under-pasteurization as well as contamination of a properly pasteurized product with raw milk can be detected by this test. 

For solvent extraction of a tetravalent vanadium oxyvanadium cation, the leach solution is acidified to ca pH 1.6—2.0 by addition of sulfuric acid, and the redox potential is adjusted to —250 mV by heating and reaction with iron powder. Vanadium is extracted from the blue solution in ca six countercurrent mixer—settler stages by a kerosene solution of 5—6 wt % di-2-ethyIhexyl phosphoric acid (EHPA) and 3 wt % tributyl phosphate (TBP). The organic solvent is stripped by a 15 wt % sulfuric acid solution. The rich strip Hquor containing ca 50—65 g V20 /L is oxidized batchwise initially at pH 0.3 by addition of sodium chlorate then it is heated to 70°C and agitated during the addition of NH to raise the pH to 0.6. Vanadium pentoxide of 98—99% grade precipitates, is removed by filtration, and then is fused and flaked. 

Phosphate. Phosphoms occurs in water primarily as a result of natural weathering, municipal sewage, and agricultural mnoff The most common form in water is the phosphate ion. A sample containing phosphate can react with ammonium molybdate to form molybdophosphoric acid (H2P(Mo202q)4). This compound is reduced with stannous chloride in sulfuric acid to form a colored molybdenum-blue complex, which can be measured colorimetrically. SiUca and arsenic are the chief interferences. 

In this biosensor a quartz radio crystal is functionalized with the enzyme glucose-6-phosphate dehydrogenase. As shown in Figure 3, a thin film of Pmssian blue [14038-43-8] C gN gFe, is then coated onto the crystal. 

The resonant frequency of the crystal is inversely proportional to the mass of the Pmssian blue coating. When the immobilized enzyme acts on its substrate, glucose-6-phosphate [54010-71-8] (4), electrons are transferred to the Pmssian blue. In order to maintain electrical neutraUty, cations... 

Fig. 4. Schematic of a multisequence biosensor in which the target glucose is first converted to glucose-6-phosphate, G6P, in the test solution by hexokinase. G6P then reacts selectively with glucose-6-phosphate dehydrogenase immobilized on the quartz crystal surface. Electrons released in the reaction then chemically reduce the Pmssian blue film (see Fig. 3), forcing an uptake of potassium ions. The resulting mass increase is manifested as a...

Phosphoms determination involves the conversion of phosphoms to soluble phosphate by digesting the coal ash with a mixture of sulfuric, nitric, and hydrofluoric acids (18). Phosphate is precipitated as ammonium phosphomolybdate, which may be reduced to give a blue solution that is determined colorimetricaHy or volumetricaHy (D2795) (18). 

Paint pigments do not change colors on appHcation. Other common colors are violet from cobalt(II) phosphate [18475-47-3] pink from cobalt and magnesium oxides, aureolin yellow from potassiuim cobalt(III) nitrite [13782-01-9], KCo(N02)4, and cerulean blue from cobalt staimate [6546-12-5]. Large quantities of cobalt are used at levels of a few ppm to decolori2e or whiten glass and ceramics. Iron oxide or titanium dioxide often impart a yellow tint to various domestic ware. The cobalt blue tends to neutrali2e the effect of the yellow. 

Copper Hydroxide. Copper(II) hydroxide [20427-59-2] Cu(OH)2, produced by reaction of a copper salt solution and sodium hydroxide, is a blue, gelatinous, voluminous precipitate of limited stabiUty. The thermodynamically unstable copper hydroxide can be kiaetically stabilized by a suitable production method. Usually ammonia or phosphates ate iacorporated iato the hydroxide to produce a color-stable product. The ammonia processed copper hydroxide (16—19) is almost stoichiometric and copper content as high as 64% is not uncommon. The phosphate produced material (20,21) is lower ia copper (57—59%) and has a finer particle size and higher surface area than the ammonia processed hydroxide. Other methods of production generally rely on the formation of an iasoluble copper precursor prior to the formation of the hydroxide (22—26). 

Figure 4.8 The active site in all a/p barrels is in a pocket formed by the loop regions that connect the carboxy ends of the p strands with the adjacent a helices, as shown schematically in (a), where only two such loops are shown, (b) A view from the top of the barrel of the active site of the enzyme RuBisCo (ribulose bisphosphate carboxylase), which is involved in CO2 fixation in plants. A substrate analog (red) binds across the barrel with the two phosphate groups, PI and P2, on opposite sides of the pocket. A number of charged side chains (blue) from different loops as welt as a Mg ion (yellow) form the substrate-binding site and provide catalytic groups. The structure of this 500 kD enzyme was determined to 2.4 A resolution in the laboratory of Carl Branden, in Uppsala, Sweden. (Adapted from an original drawing provided by Bo Furugren.)...

Figure 7.1 Schematic drawing of B-DNA. Each atom of the sugar-phosphate backbones of the double helix is represented as connected circles within ribbons. The two sugar-phosphate backbones are highlighted by orange ribbons. The base pairs that are connected to the backbone are represented as blue planks.

The sugar-phosphate backbone is represented by connected circles in color and the base pairs as blue planks. Four base pairs are shown from the top of the helix to highlight how the grooves are formed due to the asymmetric connections. The position of the helix axis is marked by a cross. 

The binding model, suggested by Brian Matthews, is shown schematically in (a) with connected circles for the Ca positions, (b) A schematic diagram of the Cro dimer with different colors for the two subunits, (c) A schematic space-filling model of the dimer of Cro bound to a bent B-DNA molecule. The sugar-phosphate backbone of DNA is orange, and the bases ate yellow. Protein atoms are colored red, blue, green, and white, [(a) Adapted from D. Ohlendorf et al., /. Mol. Evol. 19 109-114, 1983. (c) Courtesy of Brian Matthews.]... 

Figure 13.4 Schematic diagram (a) and topology diagram (b) of the polypeptide chain of cH-ras p21. The central p sheet of this a/p structure comprises six p strands, five of which are parallel a helices are green, p strands are blue, and the adenine, ribose, and phosphate parts of the GTP analog are blue, green, and ted, respectively. The loop regions that are involved in the activity of this protein are red and labeled Gl-GS. The Gl, G3, and G4 loops have the consensus sequences G-X-X-X-X-G-K-S/T, D-X-X-E, and N-K-X-D, respectively. (Adapted from E.R Pai et al., Nature 341 209-214, 1989.)...

Figure 13.8 Interactions involved in the switch from the inactive GDP- (blue) to the active GTP- (green) bound forms of G from transducin. The diagram illustrates the local changes required in the switch I and II regions in order to bring the side chain of Thr 177 and the main chain N of Gly 199 into contact with the 7 phosphate of GTP. (Adapted from D. Lambright et al., Nature 369 621-628, 1994.)...

FIGURE 23.26 The pentose phosphate pathway. The numerals in the blue circles indicate the steps discussed in the text. 

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