the Cage of a green plant. Cytoplasm movements

you are: the Cage of a green plant

Though the number organell in a cage is very great, they will defend from each other on considerable enough distance and each of them is surrounded by selectively nontight membrane. What image carries out a necessary exchange of an every possible material between separate organellami? It is necessary to search for Answer to this question partially in diffusion, and partially in tsikloze - fast enough movement peculiar to contents of many vegetative cages. At tsikloze all cytoplasm of a cage rotates (or clockwise, or against it), sliding along an internal surface of a cellular wall and carrying away with itself various organelly. Along with it there are counter and lateral streams, and in some cages, for example in tychinochnyh hairs Tradescantia, it is possible to observe active movement of cytoplasm as well in cytoplasmatic tjazhah, crossing vakuol.

The Mechanism operating movement of cytoplasm, completely is not studied yet, however is clear that in this movement take part organelly, named mikrofilamentami. mikrofilameity contain, apparently, aktin and miozin - two fibers participating in muscular reduction at animals; reduction of a muscle results from mutual displacement aktinovyh and miozinovyh the threads, accompanied by an expenditure of energy ATR. it was found out that tsikloz it is sensitive to maintenance ATR in a cage and that it proceeds actively only under those conditions at which synthesis ATR is possible. The substances breaking structure mikrofilamentov, suppress tsikloz. It is established, for example, that such medical product as tsitohalazin In, causes aggregation mikrofilamentov and at the same time suppresses, first, cytoplasm movement in many vegetative cages and, secondly, movement huge hloroplastov various seaweed. (Some hloroplasty are capable to move in cytoplasm and to be guided - usually in reply to light exposure change - so that their flat surfaces sheet surfaces) Suppression caused inkubatsiej of cages in tsitohalazine settled down in parallel or perpendicularly. It is possible to remove washing up of fabrics from this preparation.

Movings of chromosomes during a mitosis and mejoza are carried out also with the help sokratitelnyh elements, so-called microtubules. Microtubules are the extended hollow structures of some micrometers at diameter only 15-25 nanometers and a thickness ' walls ' 6 nanometers. In microtubules fiber tubulin, changing the configuration in reply to some chemical influences, for example under the influence of ions of Sa2 + contains. Microtubules are attached to a special site of chromosomes, to so-called kinetohoru, and help to take away chromosomes to opposite poles of a cage during cellular division. supplied zhgutikami cages of seaweed and mobile sexual cages (gamete) of various plants dvizhutsja also thanks to reduction of microtubules. In cross-section section zhgutiki usually have a characteristic structure: 9 steams of microtubules form a ring surrounding 2 steams, being in the centre. Plazmalemma (and, perhaps, as well tonoplast) is in continuous movement. On it arise as though ' blisters ' with which it surrounds and grasps being outside of a part or large molecules then these parts in process pinotsitoza are transported in cytoplasm in small membrannyh vials. Also return process - deducing of various materials from a cage outside similarly proceeds.

In a live cage, as well as everywhere in the nature, the structure and function are closely connected. Any detail of specific architecture of everyone cellular organelly is adapted in the unique image for performance of certain functions about which we will speak in following heads.