Electron micrograph cell membrane, figure

The overall selectivity is therefore controlled by the membrane component with a smaller resistance. The gas transport of a membrane with a structure described in Figure 5.8 is mostly through the void space between spherical polymer cells, and therefore the selectivity should be extremely low. It should be noted, however, that the resistance given by Equation 5.319 is inversely proportional to the area. A, Therefore, if the area occupied by the void space is very small (in other words, if the void spaces are eliminated by the deformation of the spherical polymer cells, as shown by an electron micrographic picture in Figure 4.7 of Chapter 4), the selectivity may become high, since it is governed by the network component of the membrane. 

FIGURE 5-31 Structure of skeletal muscle, (a) Muscle fibers consist of single, elongated, multinucleated cells that arise from the fusion of many precursor cells. Within the fibers are many myofibrils (only six are shown here for simplicity) surrounded by the membranous sarcoplasmic reticulum. The organization of thick and thin filaments in the myofibril gives it a striated appearance. When muscle contracts, the I bands narrow and the Z disks come closer together, as seen in electron micrographs of (b) relaxed and (c) contracted muscle. 

FIGURE 27-1 Ribosomes and endoplasmic reticulum. Electron micrograph and schematic drawing of a portion of a pancreatic cell, showing ribosomes attached to the outer (cytosolic) face of the endoplasmic reticulum (ER). The ribosomes are the numerous small dots bordering the parallel layers of membranes. 

Figure 8-1 Electron micrograph of a thin section of a fat storage cell or adipocyte. L, the single large fat droplet N, nucleus M, mitochondria En, endothelium of a capillary containing an erythrocyte (E) CT, connective tissue ground substance which contains collagen fibers (Co) and fibroblasts (F). The basement membranes (BM) surrounding the endothelium and the fat cell are also marked. From Porter and Bonneville.6 Courtesy of Mary Bonneville.

Figure 30-10 (A) Schematic drawing of a synapse. (B) Electron micrograph showing the synaptic junctions in the basal part (pedicle) of a retinal cone cell of a monkey.403 Each pedicle contains synaptic contacts with 12 triads, each made up of processes from a bipolar cell center that carries the principal output signal and processes from two horizontal cells that also synapse with other cones. A ribbon structure within the pedicle is characteristic of these synapses. Note the numerous synaptic vesicles in the pedicle, some arranged around the ribbon, the synaptic clefts, and the characteristic thickening of the membranes surrounding the cleft (below the ribbons). Micrograph courtesy of John Dowling.

Figure 4. Scanning electron micrographs of KB cells after butyrate treatment (a) (X400) and after TPA treatment (b) (X280). Cells prepared for microscopy simultaneously according to procedures described in text. The membrane tearing" (Figure 5b) was consistently found only in cells treated with TPA and somewhat in synchronized, late G,-early S phase cells.

Fig. 4. Transmission electron micrograph through a portion of the EHS tumor. A cell is seen at the bottom of the figure. At a distance from the cell (d), the basement membrane is seen to take on a laminated appearance (arrows), which is not apparent in the matrix proximal (p) to the cell. Courtesy of Dr. S. Inoue and Dr. C. P. Leblond, McGill University.

FIGURE 4.3 High magnification transmission electron micrographs of multilamellar membrane structures in the intercellular space of the cornified part of human epidermis. (A) cryo-electron micrograph of vitreous section. (B, C) conventional electron micrographs of resin embedded sections. The cell plasma membranes appear as 3.8 nm wide bilayers in (A) (open white arrow). A 16 nm broad zone of electron dense material, the cornified cell envelope (white asterix), is directly apposed to the cytoplasmic side of the bilayer plasma membranes in the native sample (A) (open white arrow). Scale bar 50 nm (A). Scale bars 25 nm (B, C) adapted from measures given in Swartzendruber et al. (1989). (A) reprinted from Norlen (2003). With permission from Blackwell Science Publications. (B, C) reprinted from Swartzendruber et al. (1989). With permission from Blackwell Science Publications. 

Figure 4.4. Electron micrograph showing two small lipid droplets (arrows) which, apparently, were in the process of being secreted. These droplets are partly enveloped in what appears to be plasma membrane in the apical cell region. Bar = 1 pm. From Deeney et al. (1985) with permission.

Figure 10. Representative freeze-fracture electron micrograph of competent E. coli DH1. The micrograph shows the typical appearance of small semi-regular plaques (arrows) in the plasma membranes of E. coli DH1 cells after treatment to make them genetically transformable by the method of Hanahan.146 These cells have sharp thermotropic transitions at -56 °C when examined as in Figure 9A.24...

Figure 11.12. Electron Micrograph of a Microvillus. Lactase and other enzymes that hydrolyze carbohydrates are present on microvilli that project from the outer face of the plasma membrane of intestinal epithelial cells. [From M. S. Mooseker and L. G. Tilney, J. Cell. Biol. 67(1975) 725.]...

Figure 12.1. Red-Blood-Cell Plasma Membrane. An electron micrograph of a preparation of plasma membranes from red blood cells showing the membranes as seen "on edge," in cross section. [Courtesy of Dr. Vincent Marchesi.]... 

Figure 12.36. Internal Membranes of Eukaryotes. Electron micrograph of a thin section of a hormone-secreting cell for the rat pituitary, showing the presence of internal structures bounded by membranes. [Biophoto Associates/Photo Researchers.]...

Figure 22.17. Electron Micrograph of a Peroxisome in a Liver Cell. A crystal of urate oxidase is present inside the organelle, which is bounded by a single bilayer membrane. The dark granular structures outside the peroxisome are glycogen particles. [Courtesy of Dr. George Palade.]...

Figure 30.15. Insulin Secretion. The electron micrograph shows the release of insulin from a pancreatic P cell. One secretory granule is on the verge of fusing with the plasma membrane and releasing insulin into the extracellular space, and the other has already released the hormone. [Courtesy of Dr. Lelio Orel. L. Orel, J.-D. Vassalli, and A. Perrelet. Sci. Am. 259 (September 1988) 85-94.]...

Figure 33.31. Consequences of Cytotoxic-T-Cell Action. An electron micrograph showing pores in the membrane of a cell that has been attacked by a cytotoxic T cell. The pores are formed by the polymerization of perforin, a protein secreted by the cytotoxic T cell. [Courtesy of Dr. Eckhard Podock.]... 

Figure 8. These electron micrographs by Robert Scoggins show an intact membrane-coating granule (xl96fi00) and another granule (xlOSfiOO) within an invagination of the trilaminar cell membrane (44).

Figure 5.10 Electron micrographs of L-cells of Streptomyces hydroscopicas [73]. The freeze-fractured texture shows the periodically curved lipid bilayer. The curvature is weakly expressed in a and very distinct in fi. Two attached lamellar bodies and the imderlying membrane are shown in fe. The bar (in fi) is 500 nm.

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