Glucose electron micrograph

Figure 13-13. The glycogen molecule. A General structure. B Enlargement of structure at a branch point. The molecule is a sphere approximately 21 nm in diameter that can be visualized in electron micrographs. It has a molecular mass of 10 Da and consists of polysaccharide chains each containing about 13 glucose residues. The chains are either branched or unbranched and are arranged in 12 concentric layers (only four are shown in the figure). The branched chains (each has two branches) are found in the inner layers and the unbranched chains in the outer layer. (G, glycogenin, the primer molecule for glycogen synthesis.)...

Fig. 7.1 Scanning electron micrographs of a typical carbon dispersion from glucose as a model system (scale bar 2 pm).

Figure 3. Electron micrographs of carp actomyosin before and after frozen storage in 0.05M KCl at —20°C. A and B, no additives C, 0.2M sodium glutamate added D, 1M glucose added. A, before freezing B, C and D, after 8, 9 and 9 weeks of frozen storage, respectively. Each specimen was negatively stained with uranyl actate solution (72).

Endosperm cells of a ryegrass, Lolium multiflorum, were grown in suspension culture and the cell walls recovered.261 The walls of the cultured cells were thicker than the walls in the seed. Electron micrographs indicated that the cell walls were similar to primary walls.261 The cell walls from the cultured cells contained arabinose, galactose, and xylose in the ratios of 7.3 1.9 10, and a trace of mannose was present.118 In these cell walls, as in the mesophyll cell-walls,257 glucose was present in high proportion. 

The polymer is about 0.8 nm in its maximum width and 0.33 nm2 in cross-sectional area, and can contain about 10,000 glucose residues with their rings in the same plane. In the cell wall these polymers are organized into micro-fibrils that can be 5 nm by 9 nm in cross section. These microfibrils apparently consist of an inner core of about 50 parallel chains of cellulose arranged in a crystalline array surrounded by a similar number of cellulose and other polymers in a paracrystalline array. Microfibrils are the basic unit of the cell wall and are readily observed in electron micrographs. Although great variation exists, they tend to be interwoven in the primary cell wall and parallel to each other in the secondary cell wall (Fig. 1-13). 

Electron micrograph of a chloroplast. The thylakoid membranes course throughout the stroma of a chloroplast from a cell of Phleum pratense, a grass. The dark areas of stacked thylakoid membrane are grana. Several large starch granules, which store the newly synthesized glucose, are also obvious. [Biophoto Associates/Photo Researchers.]... 

Figure 3. Electron micrograph of a pellet of glucose isomerase...

The deposition of the enzyme was very site-specific as shown in the scanning electron micrograph. Figure 5. This photo illustrates the enzyme layer deposited on top of the electrode only in the region where the top insulation layer was removed. This deposition of the enzyme only on the working electrode minimized the amount of glucose oxidase wasted and thus minimized the production costs. 

Figure 9.32 Transmission electron micrograph of (a) 0.7% gellan with 10-mN Ca " in an aqueous environment and (b) 0.7% gellan with 10-mN Ca + in the presence of 80% glucose syrup. The filamentous appearance of trace (a) is evidence for a multi-stranded or enthalpic structure. (Reprinted from [123], Copyright (2004), with permission from Elsevier.)...

Scanning electron micrograph of a needle-type glucose sensor coated with a tri-layer membrane. Using 10 kV acceleration no gold coating was needed to obtain the image. e coiled Pt electrode is located near the tip of the sensor. 

The specific activity of glucose oxidase determined to be 80 U/mg before its immobilization on sol-gel matrix. The Scanning Electrcm Micrograph (SEM) measurements were made using JEOL- JSM 840A Scanning Electron Microscope. 

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