EducationThe science

Golgi Complex

The Golgi complex was discovered by Camillo Golgi in 1898. This structure is present in the cytoplasm of virtually all eukaryotic (constituent higher organisms) cells, in particular, secretory cells in animals.

The Golgi complex. Structure.

The structure is represented by a stack of flattened membrane pouches. They are called cisterns. This stack of bags is associated with a system of bubbles ( Golgi bubbles ). From one end of the pile of pouches constantly forms new tanks with the fusion of bubbles, which bud off from the endoplasmic reticulum (network of cavities). From the other end of the pile, from the inside, the cisterns complete ripening and disintegrate again into bubbles. So there is a gradual movement of cisterns in the hill to the inner side from the outer side.

The maturation of proteins intended for secretion, transmembrane proteins of the plasma membrane, proteins of lysosomes and others takes place in the cisterns of the structure. The ripening substances are moved sequentially along the organelle cisterns. In them, the final coagulation of proteins and their modifications - phosphorylation and glycosylation.

Vegetative cells are characterized by the presence of a number of individual diktios (stacks). In animal cells, there are often several stacks of tubes connected together or one large stack.

The apparatus (complex) Golgi contains four main departments: trans-Golgi network, cis-Golgi, trans-Golgi and medial-Golgi. An intermediate compartment (a separate region) is also attached to the structure. It is represented by the accumulation of membrane vesicles in the interval between the reticulum and cis-Golgi.

The entire apparatus is an organelle of very polymorphic (diverse) form. Even at different stages in the development of a single cell, the Golgi complex may look different.

The apparatus differs in its asymmetry. Located nearer to the cell nucleus of the cistern (cis-Golgi) contain the most immature proteins. To the tanks this is joined continuously membrane vesicles - vesicles. Different cisterns contain various resident enzymes (catalytic), which indicates that in them with sequestering proteins there are consistently different processes.

The Golgi complex. Functions.

The tasks of the structure include chemical modification and transport of substances entering it. Proteins penetrating the apparatus from the endoplasmic reticulum are for the enzymes the initial substrate. After concentration and modification, the enzymes in the vesicles are transported to the designated site. For example, this may be the area of formation of a new kidney. With the participation of cytoplasmic microtubules, the transfer process is most active.

The Golgi complex also performs the task of attaching carbohydrate groups to proteins and the subsequent use of these proteins in the construction of the lysosome membrane and cells.

Separate algae in the structure of the apparatus synthesizes cellulose fibers.

The functions of the Golgi complex are quite diverse. Among them, it should be noted:

  1. Sorting, excretion, accumulation of secretory products.
  2. Accumulation of lipid molecules and formation of lipoproteins.
  3. Completion of the modification of proteins (post-translational), namely glycosylation, sulfation and other.
  4. Formation of lysosomes.
  5. Participation in the formation of the acrosome.
  6. Polysaccharide synthesis for the formation of waxes, glycoproteins, mucus, gum, matrix substances in the cell walls of plants (pectins, hemicellulose and others).
  7. Formation of contractible vacuoles in protozoa.
  8. The formation of a cell plate in plant cells after division of the nucleus.

Similar articles

 

 

 

 

Trending Now

 

 

 

 

Newest

Copyright © 2018 en.delachieve.com. Theme powered by WordPress.