Lysosomes

Lysosomes (lysosomae) — it is a various class of spherical structures of 0,2 in size — 0,4 microns limited to a single membrane. A characteristic sign of lysosomes is availability in them of hydrolytic enzymes — a hydromanhole, splitting various biopolymers. Examples lizosomnykh hydromanhole: phosphatases, proteinases, lipases, etc. Lysosomes were opened in 1949 by de Duv.

It is possible to distinguish from lysosomes at least 3 types: primary lysosomes, secondary lysosomes (fagolizosoma and autofagosoma) and residual little bodies (fig. 11). A variety of morphology of lysosomes is explained by that these particles participate in processes of intracellular digestion, forming difficult digestive vacuoles both exogenous (extracellular), and an endogenous (intracellular) origin.

Primary lysosomes represent the small membrane bubbles about 0,2 — 0,5 microns in size filled with the unstructured substance containing hydromanholes, including active sour phosphatase which is enzyme, marker for lysosomes. It is practically very difficult to distinguish these small bubbles from small vezikul by peripheries of a zone of a complex of Golgi which also contain sour phosphatase. A place of its synthesis is the granular endoplasmic network, then this enzyme appears in proximal sites diktiosy, and then in small vezikula on the periphery diktiosy and, at last, in primary lysosomes.

Thus, all way of formation of primary lysosomes is very similar to education the sekretornykh (zimogennykh) of granules in cells of a pancreas, except for the last stage — ejection from a cage.

Secondary lysosomes, or intracellular digestive vacuoles, are formed at merge of primary lysosomes to fagotsitarny vacuoles (fagosoma) or pinotsitozny vacuoles, forming fagolizosoma, or geterofagosoma. Primary lysosomes can merge with the changed organellas of the cage which are exposed to digestion (a so-called autofagosoma). Thus enzymes of primary lysosome get access to substrata which they also start splitting. The substances which got to structure of a secondary lysosome are split by hydromanholes to monomers which are transported through a lysosome membrane in a gialoplazma where they reutilizirutsya, i.e. join in various exchange processes.

In the autofagosomakh fragments or even the whole cytoplasmatic structures, for example mitochondrions, elements of a cytoplasmatic network, a ribosome, a glycogen granule, etc. are found out that is the proof of their defining role in degradation processes.

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