Transmission electron membranes

The spatial arrangement of atoms in two-dimensional protein arrays can be detennined using high-resolution transmission electron microscopy [20]. The measurements have to be carried out in high vacuum, but since tire metliod is used above all for investigating membrane proteins, it may be supposed tliat tire presence of tire lipid bilayer ensures tliat tire protein remains essentially in its native configuration. 

Fig. 13.9 Transmission electron microscopic data ofendocytosis. Saos-2 cell was treated with LDH and after 1 h the cell was fixed and subjected to TEM measurement. (A) successive internalization of LDH via endocytosis access of LDH around plasma membrane, formation of membrane ruffles and interaction...

The er is a three-dimensional membrane system (57-62). As visualized in a transmission electron microscope, there are two parallel membranes with an intervening electron transparent space, the lumen. The form and abundance of the er vary. The rer are flattened sacs with numerous attached ribosomes (15-20 nm). In contrast, the smooth er (ser) lacks ribosomes. The er seems to function as a communication system within cells and can be continuous with the outer nuclear envelope. Although the rer is involved in protein synthesis, the ser functions in glycosylation. 

Figure 3. Example of intracellular membrane organisation a transmission electron microscopy (TEM) image of a section through the thylakoid stack from a chloroplast. (Source http //www.ru.ac.za/administrative/emu/grl0p6.htm, Reproduced with permission from Dr. R. Cross)...

Transmission electron microscope (TEM) revealed that cellular membranes bursted during ECT and morphological changes corresponding to inhibition of cell proliferation were visible.37... 

Interestingly, the cellular distribution was analyzed by energy-filtered transmission electron microscopy and electron tomography, demonstrating the presence of free fullerene in the cytoplasm, or associated with nuclear membrane, plasma membrane, lysosomes and, rather surprisingly, with the nucleus (Porter et al., 2006, 2007). 

FIG. 3. Transmission electron micrograph of a microtomed section of a polycarbonate template membrane after deposition of An tubules within the pores of the membrane. Pore diameter was 50 mn. 

Xue, T., Trent, J. S. and Osseo-Asare, K. 1989. Characterization of Nafion membranes by transmission electron microscopy. Journal of Membrane Science 45 261-271. 

Figure 3J. Transmission electron micrographs of (a) membrane precursor crystallites and (b) a thin, unsupported membrane film.

Ultrastructural examination of duckweed frond (Fig. 5) and root tissues treated with 18 (100 xM) revealed membrane damage to the tonoplast after 12 hours of exposure. The samples viewed through the transmission electron microscope showed ruptured tonoplasts, free-floating organelles and loss of cytoplasm relative to control tissues. The tonoplast may be the primary target for the phytotoxic effect of 18, which represents an unusual, if not unique, toxic mechanism among phytotoxic agents. 

Figure 10.10 Transmission electron micrograph of ferritin entrapped in POPC liposomes (palmitoyloleoylphosphatidylcholine). Cryo-TEM micrographs of (a) ferritin-containing POPC liposomes prepared using the reverse-phase evaporation method, followed by a sizing down by extrusion through polycarbonate membranes with 100 nm pore diameters ([POPC] = 6.1 mM) and (b) the vesicle suspension obtained after addition of oleate to pre-formed POPC liposomes ([POPC] = 3 mM, [oleic acid - - oleate] = 3 mM). (Adapted from Berclaz et al, 2001a, b.)...

Horisberger, M., Rosset, J. and Vonlanthen, M. 1977. Location of glycoproteins on milk fat globule membrane by scanning and transmission electron microscopy, using lectin-labelled gold granules. Exp. Cell Res. 109, 361-369. 

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