. Plasmodomy of the cells:
A) A schematic diagram of the electron microscopic image of two walls separating the adjacent cells at the root of the meadow comet (Phleum pratense) is shown on the left.
It is now generally accepted that the entire cell wall system of the whole plant is considered to be a coherent structural and functional unit. In particular, it should be emphasized that the cohesive cell
Cells without protoplast are specialized in performing various functions such as transport or consolidation. For example, high-level tracheids, which are the transport elements of xylem, have no special protoplasts during cell differentiation, but have a thick secondary wall (see Chapter II).
Cell wall-forming polymers: The main components are cellulose, pectin, hemicellulose, lignin, subergy (paraffin) and (structural and enzyme) proteins.
Cellular material of the cell wall is cellulose. Cellulose is a polysaccharide of β-D-glucan. Cellulose molecules in the cell wall are sorted by a kind of hierarchy, i.e., from smaller units to larger ones, the micelles of the simple cellulose chains, microfibrils of micelles and the microfibrils form macrophytes.
The cellulose chain itself consists of 1 to 3,000 cellulose molecules that are linked to each other by β-1-4 bonds. The micelles are crystalline cellulose chains, 1 micellum approx. It consists of 100 strips of cellulose adjacent to each other. Many consider micellum to be the smallest structural unit of the cell wall.
The next unit is approx. Microfibrum 20 micellum. It has a cross-section of 15-25 nm. It is estimated that a microfibrillum is formed from 2,000 cellulose chains and 250 microfibrils form a macrofibrillum. Macrofibrils resemble a woven bandage bonded by pectin bridges to provide cell wall strength: 4 μm wide and 3.5 μm long.
Removal of non-cellulosic components from the cell wall in the cell wall structure or in the physical properties of the cell wall only causes minor changes, suggesting that these components are embedded in a cellulose frame. In fact, a simple cotton fiber (that is, a core shell), which is clearly visible to the naked eye, consists of 1500 microfibrils.
Pectins, together with hemicelluloses and proteins, form the core (matrix) of the middle plate and cell walls. Most of the pectic substances are made up of polygalacturonic acid chains, the two main groups of which are homogalacturans (barely branched, acidic) and ramnogalacturans (branched, weakly acidic). Hemicelluloses, along with pectin, are non-cellulosic (150-200 member) polysaccharides of the cell wall. They are linked to and run parallel to the pulp bundles. Hemicelluloses of the primary cell walls are primarily glucans, while the secondary cell walls are primarily mannans (conifers) and xylans (deciduous trees). Hemicelluloses include the callus (glucose molecules polymerized into a helical chain) that are likely to occur in small amounts in all cell walls. Matrix-forming proteins are soluble and insoluble glycoproteins.
Incremental materials are compounds incorporated into the cellulosic microfibrils and fibrils of the cell wall. Among them, the lignin (so-called wood), which is incorporated into the interface of the secondary cell wall, is the most significant. A chemopolymer of heteropolymer of phenylpropane (aromatic alcohol) to increase tissue hardness. Polymer of para (suberrient) hydroxyric acids, hydrophobic material. Diffusion resistance is formed at water dispersion (cell wall of secondary tissue on the surface: periderma: page 53) and in material transport (endoderm: page 59). The so-called. Adhesive materials are the intracellular cavities and complex lipids on the outer wall of skin tissue cells such as waxes (esters of saturated fatty acids and high molecular alcohols) and cutin (hydroxyric acid polymers).
During cell division (cytokinesis), the formation of the new cell wall in the last phase of mitosis (counting cell division), the so-called "cellular division". begins in a telophase. The microtubules of the cytoplasm are then arranged in the equatorial plane of the cell. In the early stages of cell division, small vesicles and bladders are also aligned in the equatorial plane of the mother cell, thereby creating a partition separating the two progeny cells, the fragment. The fragments of the fragmoplast are the fragments which are derived from ER (dictosomes). The fragmoplasm is the two new plasma plasmic surfaces between the two progeny cells, including the fragments of the fragments. The channels of the fragmoplast are the cotyledon crosstalk sites and the primary plasmodosmoses. Following the formation of the fragmoplast, the formation of the primary cell wall surfaces begins, which passes centrifugally from the center of the fragment to the wall of the mother cells. (The above cellular cell
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