Golgi apparatus animal cell

In spite of the variety of appearances of eukaryotic cells, their intracellular structures are essentially the same. Because of their extensive internal membrane structure, however, the problem of precise protein sorting for eukaryotic cells becomes much more difficult than that for bacteria. Figure 4 schematically illustrates this situation. There are various membrane-bound compartments within the cell. Such compartments are called organelles. Besides the plasma membrane, a typical animal cell has the nucleus, the mitochondrion (which has two membranes see Fig. 6), the peroxisome, the ER, the Golgi apparatus, the lysosome, and the endosome, among others. As for the Golgi apparatus, there are more precise distinctions between the cis, medial, and trans cisternae, and the TGN trans Golgi network) (see Fig. 8). In typical plant cells, the chloroplast (which has three membranes see Fig. 7) and the cell wall are added, and the lysosome is replaced with the vacuole. 

The most important membranes in animal cells are the plasma membrane, the inner and outer nuclear membranes, the membranes of the endoplasmic reticulum (ER) and the Golgi apparatus, and the inner and outer mitochondrial membranes. Lysosomes, peroxisomes, and various vesicles are also separated from the cytoplasm by membranes. In plants, additional membranes are seen in the plastids and vacuoles. All membranes show polarity—e., there is a difference in the composition of the inner layer (facing toward the cytoplasm) and the outer layer (facing away from it). 

Figure 1 A schematic representation of the Ca + transporters of animal cells. Plasma membrane (PM) channels are gated by potential, ligands or by the emptying of Ca + stores. Channels in the ER/SR are opened by lnsP3 or cADPr (the cADPr channel is sensitive to ryanodine and is thus called RyR). ATPase pumps are found in the PM (PMCA), in the ER/SR (SERCA), and in the Golgi apparatus (SPCA). The nuclear envelope, which is an extension of ER, contains the same transporters of the latter. NCXs are located in the PM (NCX) and in the inner mitochondria membrane (mNCX). A uniporter (U) driven by the internal negative potential (-180 mV) transports Ca + into mitochondria. Ca +-binding proteins are represented with a sphere containing the four EF-hands Ca +.binding sites.

Bacteria and other prokaryotes lack the complex intracellular structures (endoplasmic reticulum, Golgi apparatus, lysosomes, mitochondria, etc.) found in plant and animal cells (eukaryotes). Bacterial morphology (shape and size) is limited to... 

Histochemical studies indicate that ascorbic acid is highly concentrated in the Golgi apparatus, and mitochondrial elements in the animal cell (Bourne, 1935) and these show changes in scorbutic animals which are rectified when ascorbic acid is supplied (Miwa, 1939). The most definite evidence we have as yet of the site of formation within the cell comes, as we have already seen, from the work of Mapson et al. (1954), who have shown that at least one stage in the synthesis is catalyzed by enzymes localized within the mitochondria. These observations have now been extended to animals, where very similar results have been obtained with mitochondria from liver tissue (Isherwood et al., 1954). 

Pagano, R. E. A fluorescent derivative of ceranude physical properties and use in studying the Golgi apparatus of animal cells. Methods Cell Biol. 1989, 29, 75-85. 

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