§fifteen. Endoplasmic reticulum

Cage - solid system

Live cell is a unique perfect smallest unit of the body, it is designed to use oxygen and nutrients as efficiently as possible, performing their functions. Orgellam, ribosomes, mitochondria, endoplasmic reticulum, Golgi devices are vital for cells. That's the last and talk more.

What it is

This membrane organella is a complex of structures that are derived from the cell synthesized in it substances. Most often it is located close to the outer cell membrane.

Machine Golgji: Building

It consists of "bags" formed by membranes, called tanks. The latter have an elongated form, slightly flattened in the middle and expanded around the edges. Also in the complex there are round golgi bubbles - minor membrane structures. The tanks are "composed" with a pile, which are called docyoma. The Golgi apparatus contains various types of "bags", the entire complex is divided into some parts by the degree of remoteness from the kernel. Three are distinguished by three: a cis-department (closer to the kernel), the middle, and the trans-department is the farthest from the kernel. They are characterized by the characteristic composition of enzymes, and therefore, the work performed. In the building, dokyosis there is one feature: they are polar, that is, the unit closest to the kernel only takes bubbles coming from the endoplasmic reticulum. Part of the "stacks" facing the cell membrane only forms and gives them.

Machine Golgji: Functions

The main tasks are sorting proteins, lipids, mucous secrets and their elimination. Also through it, non-cellular non-cells, carbohydrate components of the outer membrane are trained. At the same time, the Golgi apparatus is not at all an indifferent mediator who simply "transmits" substances, it is processes to activate and modify ("maturation"):

1. Sorting substances, transport proteins. The distribution of protein substances occurs on three streams: for the membrane of the cell itself, export, lysosomal enzymes. In addition to proteins, fats are included in addition to proteins. Interesting factthat any export substances are transferred inside bubbles. But the cells intended for the membrane are embedded in the transport bubble membrane and are moved in this way.
2. Allocation of all products produced in the cell. The Machine of Golgi "packages" all products, both protein and other nature, in secretory bubbles. All substances are allocated to the outside by the complex interaction of the latter with the cell membrane.
3. Synthesis of polysaccharides (glycosaminoglycans and components of the cell wall glycicalis).
4. Sulfatization, glycosylation of fats and proteins, partial proteasolysis of the latter (necessary for translation from inactive form in active) - these are all the processes of "maturation" proteins that are necessary for their future full-fledged work.

Finally

Having considered how the Golgji Complex works, we are convinced that it is the most important and integral part of any cell (especially secretory). A cell that does not produce substances for export can also not do without this orgella, since "staffing" depends on it cell membrane and other important internal processes of vital activity.

Structure known today as complexor machinery of Golgi (AG) For the first time discovered the Italian scientist Camillo Golgi in 1898

In detail to study the structure of the Golgi complex, it was much longer possible with the help of an electron microscope.

Ag It is a stack of flattened "tanks" with extended edges. The system of small single-mounted bubbles is connected with them (Golgi bubbles). Each stack usually consists of 4-x-6 "tanks", is a structural-functional unit of the Golgi apparatus and is called the docyoma. The dontyom number in the cell ranges from one to several hundred.

The Golgi apparatus is usually located near the cell nucleus, near EPS (in animal cells often near the cellular center).

Golgi complex

Left - in a cage, among other organides.

Right - Golgi Complex with membrane bubbles separated from him

All substances synthesized on ePS membranes Torn B. golgi complex in membrane bubbleswhich are buded from the EPS and then merge with the Golgi complex. Admitted organic substances from EPS undergoes further biochemical transformations, accumulate, are packaged in membrane bubbles And delivered to those places of the cell where they are necessary. They are involved in completing cell membrane or allocated to the outside ( secreted) From the cell.

Functions of the Golgi apparatus:

1 Participation in the accumulation of products synthesized in the endoplasmic network in their chemical restructuring and maturation. In the tanks of the Golgi complex, the synthesis of polysaccharides occurs, their complexation with protein molecules.

2) Secretorial - the formation of ready-made secretory products, which are outlined beyond the cells by exocytosis.

3) updating cell membranes, including plasmolm sections, as well as the replacement of plasma-defects in the process of cell's secretory activity.

4) Lizosoma formation place.

5) transport substances

Lysosomes

Lizosome was opened in 1949 K. de Die ( Nobel Prize in 1974).

Lysosomes - Single-grams organoids. Present small bubbles (diameter from 0.2 to 0.8 microns) containing a set of hydrolytic enzymes - hydrolase. Lizosome can contain from 20 to 60 different species Hydrolytic enzymes (proteinases, nucleases, glucosidases, phosphatases, lipases, etc.), splitting various biopolymers. Splitting substances with the help of enzymes call lysis (lysis decay).

Lizosoma enzymes are synthesized on a rough EPS, move to the Golgi apparatus, where their modification and packaging occurs in the membrane bubbles, which, after separation from the Golgi apparatus, become actually lysosomes. (Lysosomes are sometimes called "stomachs" cells)

Lizosome - a membrane bubble containing hydrolytic enzymes

Functions lysosomes:

1. Splitting of substances absorbed as a result of phagocytosis and pinocytosis. Biopolymers are split up to monomers who come into the cell and are used for its needs. For example, they can be used to synthesize new organic substances Or may be subjected to further cleavage for energy.

2. Destroy old, damaged, excessively organoids. The destruction of organoids can occur during the hunger cell.

3. Avtoliz (self-destruction) of cells (tissue liquefaction in the inflammation zone, destruction of cartilage cells during the formation of bone tissue, etc.).

Autoliz -this is self-destruction cells resulting from the release of content lysosom inside the cell. Thanks to this lysosomes in a joke called "Suicide guns. Autoliz is a normal phenomenon of ontogenesis, it can be distributed both on individual cells and on all the fabric or organ, as it happens when the tip of the tip of the tip during the metamorphosis, i.e., when turning the headstuffs in the frog

Endoplasmic reticulum, Golgi and Lizosomaform unified vacuolar cell system, Separate elements of which can go to each other when restructuring and changing the membrane function.

Mitochondria

The structure of mitochondria:
1 - outer membrane;
2 - internal membrane; 3 - matrix; 4 - Crista; 5 is a multimenme system; 6 - Ring DNA.

In the form of mitochondria, there may be rolled, rounded, spiral, cupid, branched. The length of mitochondria ranges from 1.5 to 10 microns, diameter - from 0.25 to 1.00 microns. The amount of mitochondria in the cell can reach several thousand and depends on the metabolic activity of the cell.

Mitochondria is limited two membranes . Outdoor membrane Mitochondria smooth, internal forms numerous folds - crysti. Crysts increase the surface area of \u200b\u200bthe inner membrane. The number of CRIST in mitochondria may vary depending on the needs of the cell in energy. It is on the inner membrane that numerous enzyme complexes involved in the synthesis of adenosine trifhosphate (ATP) are concentrated. Here is energy chemical ties turns into rich energy (macroergic) communication ATP . Moreover, in mitochondria, the splitting of fatty acids and carbohydrates with the release of energy, which accumulates and is used on growth and synthesis processesIncreased data from organelle called matrix. It contains ring DNA and RNA, minor ribosomes. Interestingly, mitochondria is semi-autonomous organides, because they depend on the functioning of the cell, but at the same time they can maintain a certain independence. So, they are able to synthesize their own proteins and enzymes, as well as multiply independently (mitochondria contain its own chain of DNA, in which up to 2% of the DNA of the cell itself) is concentrated.

Functions Mitochondria:

1. Transformation of chemical bonds in Macroeergic relations ATP (Mitochondria - "Energy Stations" Cells).

2. Participate in cellular respiration processes - oxygen cleavage of organic substances.

Ribosomes

Ribosome structure:
1 - a large subunit; 2 - Small subunit.

Ribosomes -unmambustic organoids, diameter of about 20 nm. Ribosomes consist of two fragments - a large and small subunit. Chemical composition Ribosomes - proteins and RRNA. RRNA molecules are 50-63% of the mass of ribosomes and form its structural framework.

During the biosynthesis, the ribosoma protein can "work" by one or unite into the complexes - polyribosomes (polisomas). In such complexes, they are connected with each other by the same INK molecule.

Ribosomes in the nucleoline are formed. Passing through the pores in the ribosoma nuclear shell enter the membranes of the endoplasmic network (EPS).

Ribosoma function: Assembly of the polypeptide chain (synthesis of protein molecules from amino acids).

Cytoskeleton

Cell cytoskeleton is formed microtubes and microfilaments .

Microtubule. Present cylindrical formations with a diameter of 24 nm. Their length is 100 μm-1 mm. The main component is a protein called tubulin. It is unable to reduce and can collapse under the action of colchicine.

Microtubules are located in the hyaloplasm and perform the following functions:

· Create an elastic, but at the same time durable cell framework, which allows it to preserve the form;

· Take part in the process of distribution of the chromosomes of the cell (form spinning divisions);

· Provide the movement of organelle;

Microfilaments- Threads that are placed under the plasma membrane and consist of a actin or mosisin protein. They can decline, resulting in moving the cytoplasm or the protrusion of the cell membrane. In addition, these components take part in the formation of a tank in cell division.

Cell Center

The cellular center is an organoid consisting of 2 small granules of centrioles and the radiant sphere around them - the centrofer. Centriol is a cylindrical caller with a length of 0.3-0.5 μm and a diameter of about 0.15 μm. The walls of the cylinder consist of 9 parallel to the tubes. Centrioles are placed in pairs at right angles to each other. The active role of the cellular center is detected during cell division. Before dividing the cells, the centrioles diverge to the opposite poles, and a subsidiary of a centril arises near each of them. They form spine divisions that contribute to the uniform distribution of genetic material between the daughter cells.

Centrioli refers to the self-reproducing cytoplasm organoids, they arise as a result of the duplication of already available centrioles.

Functions:

1. Ensuring the uniform discrepancy of chromosomes to the cell poles during mitosis or meiosis.

2. Center for the organization of the cytoskeleton.

Motion organides

Are not present in all cells

The movements include cilia, as well as flagella. These are miniature grows in the form of hairs. The flashell contains 20 microtubes. Its base is placed in the cytoplasm and is called basal tales. The flank length is 100 microns or more. Flagellas that have only 10-20 microns are called cilia . When sliding microtubules, cilia and flagellas can fluctuate, causing the movement of the cell itself. The cytoplasm may contain contractual fibrils, which are called miofibrils. Myofibrillas are usually placed in myocytes - muscle tissue cells, as well as in heart cells. They consist of smaller fibers (Protofibril).

In animals and man ciliathey cover the air-capable respiratory tract and help get rid of small solid particles, for example, from dust. In addition, there are still pseudo-peaks that provide an amoeboid movement and are elements of many single-milking and animal cells (for example, leukocytes).

Functions:

Specific

Core. Chromosomes

The structure and functions of the core

As a rule, the eukaryotic cell has one coreBut there are duid (infusoria) and multi-core cells (opalin). Some highly specialized cells are secondally lost the kernel (mammalian erythrocytes, coated tubes).

The core shape is spherical, ellipsed, less frequently vane, beanoid, etc. The diameter of the nucleus is usually from 3 to 10 microns.

Kernel structure:
1 - outer membrane; 2 - internal membrane; 3 - pores; 4 - Yardshko; 5 - heterochromatin; 6 - Eukhromatin.

Core Received from the cytoplasm with two membranes (each of them has a typical structure). Between the membranes is a narrow gap filled with a semi-liquid substance. In some places, the membranes merge with each other, forming pores through which the metabolism is met between the core and the cytoplasm. The outer nuclear membrane from the side facing the cytoplasm is covered with ribosomes that give it roughness, the inner membrane is smooth. Nuclear membranes are part of the cell membrane system: The external nuclear membrane grows are connected to the channels of the endoplasmic network, forming a unified system of communicating channels.

Karioplasm (nuclear juice, nucleoplasm) - the internal contents of the kernel in which are located chromatin and one or more nucleoli. The composition of the nuclear juice includes various proteins (including core enzymes), free nucleotides.

Nadryshko It is a rounded dense caller immersed in nuclear juice. The number of nucleols depends on the functional state of the nucleus and varies from 1 to 7 or more. Nucleists detect only in weekly nuclei, during mitosis they disappear. Yazryshko is formed at certain sections of chromosomes carrying information on the RRNA structure. Such sites are called the nuclear organicer and contain numerous copies of genes encoding RRNA. From RRNA and proteins coming from cytoplasm, ribosomes subunits are formed. Thus, the nucleolo is a cluster of RRNA and ribosomal subunits at different stages of their formation.

Chromatin - Internal nucleoprote-shaped kernel structures, staining with some dyes and differ in shape from the nucleoline. Chromatin has the appearance of a stick, granules and threads. Chemical composition of Chromatina: 1) DNA (30-45%), 2) Histon proteins (30-50%), 3) non-regional proteins (4-33%), therefore, chromatin is a deoxyribonucleotopoid complex (DNP). Depending on the functional state of chromatin distinguishes: heterochromatin and eukhromatin .

Eukhromatin - genetically active, heterochromatin - genetically inactive sections of chromatin. Euchromatin with light microscopy is not distinguishable, weakly stains and is decondes (despondivated, promoted) sections of chromatin. Heterochromatin Under a light microscope, there is a form of a stick or granules, intensively stained and is condensed (spiralized, compacted) sections of chromatin. Chromatin - the form of the existence of genetic material in interphase cells.During cell division (mitosis, meyosis), chromatin is converted to chromosome.

The core functions:

1. Storage hereditary information and transmitting it to daughter cells during the division.

2. Control of protein biosynthesis process.

3. Regulation of cell division and organism development processes.

4. Place of formation of subunits Ribosomes.

Chromosomes

Chromosomes - These are cytological rodged structures, which are condensed chromatin and appearing in a cell during mitosis or meiosis. Chromosome and chromatin - various forms Spatial organization of the deoxyribonucleoprotein complex, corresponding to different phases life cycle Cells. The chemical composition of chromosomes is the same as chromatin: 1) DNA (30-45%), 2) Histon proteins (30-50%), 3) non-secretone proteins (4-33%).

The basis of the chromosome is one continuous two-stranded DNA molecule; DNA length of one chromosome can reach multiple centimeters. It is clear that the molecule of such a length cannot be located in the cell in an elongated form, and is subjected to laying, acquiring a certain three-dimensional structure, or conformation.

Currently adopted nucleosomal model Organizations Chromatina Eukaritis.

In the process of converting chromatin in chromosomes, spirals, superspiral, loops and superpells are formed. Therefore, the process of formation of chromosomes, which occurs in mitosis proofs or 1 meiosis proofased, is better to call not spiralization, but by condensation by chromosomes.

Chromosome: 1 - meticenter; 2 - submetrical; 3, 4 - acrocentric.

The structure of the chromosome: 5 - centromer; 6 - secondary hauling; 7 - satellite; 8 - chromatids; 9 - Telomers.

Methazna chromosome (Chromosomes are studied in mitosis metaphase) consists of two chromatids. Any chromosome has primary drawing (centruller) (5), which divides chromosome on the shoulders. Some chromosomes have secondary pigeon (6) and satellite (7). Satellite - section of the short shoulder separated by a secondary hawk. Chromosomes having satellite are called satellite (3). Chromosomes are called telomerees (nine). Depending on the position of centromers allocate: a) metuclear (Equal Run) (1), b) submetrical (moderately unequal) (2), c) acrocentric (sharply inequalization) chromosome (3, 4).

Somatic cells Contain diploid (double - 2n) set of chromosomes, germ cells - gaploid (Single - N). The diploid set of ascarides is 2, drosophila - 8, chimpanzees - 48, river cancer - 196. The chromosome of the diploid set is divided into pairs; the chromosome of one pair have the same structure, sizes, a set of genes and are called homologous.

Functions chromosomes: 1) storage of hereditary information

2) Transfer of genetic material from the maternal cell to the child.

Structure

The Golges complex is a stack of disk-shaped membrane bags (tanks), somewhat extended closer to the edges and the associated system of Golgi bubbles. In plant cells, a number of separate stacks (disosomes) are found, animal cells often contain one large or more stacks connected by tubes.

Transport substances from an endoplasmic network

The Machine is asymmetric - tanks located closer to the core of the cell ( cis-Goljezhi) contain the least mature proteins, membrane bubbles are continuously connected to these tanks - vesicles, reconnecting from the granular endoplasmic reticulum (EPR), on the membranes of which and the synthesis of proteins of ribosomes occurs. The movement of proteins from the endoplasmic network (EPS) to the Golgi apparatus occurs in indiscriminately, but not completely or incorrectly crushed proteins remain in the EPS. The return of proteins from the Golgji apparatus in EPS requires the presence of a specific signaling sequence (lysine-asparagin-glutamine-leucine) and occurs due to the binding of these proteins with membrane receptors to Cis Golgi.

Modification of proteins in the Golgi apparatus

In the tanks of the Golgi apparatus, proteins are ripening intended for secretion, transmembrane plasma membrane proteins, proteins of lysosomes, etc. The ripening proteins are successively moving along the tanks of organelles, in which their modifications are modified - glycosylation and phosphorylation. When o-glycosylation, complex sugars through oxygen atom are attached to proteins. In phosphorylation, an orthophosphoric acid residue is attached to proteins.

Different tanks of the Golgi apparatus contain different resident catalytic enzymes and, therefore, different processes occur with ripening proteins in them. It is clear that such a step process should somehow control. Indeed, the ripening proteins are "marked" with special polysaccharide residues (mainly mannose), apparently playing the role of a kind of "quality mark".

It is not fully understood how ripening proteins move along the tanks of the Golgi apparatus, while resident proteins remain more or less associated with one tank. There are two interconnecting hypotheses explaining this mechanism. According to the first (1), the transport of proteins is carried out using the same vesicular transport mechanisms, as well as the path of transport from EPR, and resident proteins are not included in the rebeling vesicula. According to the second (2), there is continuous movement (maturation) of the tanks themselves, their assembly of bubbles from one end and disassembling from the other end of the organelles, and resident proteins move retrograde (in the opposite direction) with vesicular transport.

Transport proteins from Golgi

In the end of trance-Goljei buds bubbles containing completely mature proteins. The main function of the Golgi apparatus is sorting proteins passing through it. In the Golgi apparatus, the formation of a "three-directed protein flow" is forming:

1. ripening and transport of plasma membrane proteins;
2. ripening and transport secrets;
3. ripening and transport of enzymes lysosomes.

With the help of vesicular transport, the Golgi proteins passed through the ATAPArat are delivered by "at the address" in the dependence of the "labels" obtained in the Machine apparatus. The mechanisms of this process are also not fully understood. It is known that the transport of proteins from the Goldzhi apparatus requires the participation of specific membrane receptors that identify the "cargo" and provide an electoral bubble dock with a particular organelle.

Lizosoma education

All hydrolytic enzymes of lysosome pass through the Golgi apparatus, where they receive a "label" in the form of specific sugar - mannose-6-phosphate (M6F) - as part of its oligosaccharide. The connection of this label occurs with the participation of two enzymes. The N-aceenzyme specifically identifies the lysosomal hydrolauses by the details of their tertiary structure and is attached to the N-acetylglucosaminephosphate to the sixth atom of several mannose residues of oligosaccharide hydrolase. The second enzyme - phosphoglycosidase - rolls n-acetylglucosamine, creating a M6F label. Then this label is recognized by the M6F protein-receptor, with its help hydrolase are packaged in vesicles and delivered in lysosomes. There, in an acidic environment, phosphate is cleaved from mature hydrolase. In disruption of the operation of N-acedue to mutations or attendant defects of the M6F receptor, all enzymes lysosomes "by default" are delivered to the outer membrane and secreted into the extracellular medium. It turned out that in normal number of M6F receptors also fall on the violated membrane. They return randomly external environment Enzymes lysosomes inside the cell in the process of endocytosis.

Transport proteins on the outer membrane

As a rule, during the synthesis, the outer membrane protein is embedded with its hydrophobic sites in the membrane of the endoplasmic network. Then, as part of the membrane, they are delivered to the Golgi apparatus, and from there to the surface of the cell. When merging vesicles with a plasmamama, such proteins remain in its composition, and not stand out into the external environment, as those proteins that were in the cavity of the vesicles.

Secretion

Almost all secreted cells of the substance (both protein and non-protein nature) pass through the Machinery and there are packaged in secretory bubbles. So, in plants, with the participation of the dontyom, the cell wall material is secreted.

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Watch what is "Complex Golgji" in other dictionaries:

The Golgi apparatus, the plate complex (complex Lamellosus), a cellular organoid that performs a number of important functions. K. Golgji (1898) in nerve cells. With the help of electron microscopy, it was shown that K. G. is present in all ... ... Biological Encyclopedic DictionaryTechnical translator directory

- (Golgi Complex) (named K. Golges) Organoid cells involved in the formation of products of its livelihoods (various secrets, collagen, glycogen, lipids, etc.), in the synthesis of glycoproteins ... Big Encyclopedic Dictionary

Camillo Golgi (Golgi) (7.7.1844, Corteno, 21.1.1926, Pavia), Italian Histologist, University Professor in Pavia (from 1875). Developed a chromosrebry method of preparation of microscopic drugs of nervous tissue (1873), which made it possible ... ... Great Soviet Encyclopedia

Golgi Complex (named K. Goldzhi), Organelles Cells participating in the formation of products of its livelihoods (Split. Secrets, collagen, glycogen, lipids, etc.), in the synthesis of glycoproteins ... Natural science. encyclopedic Dictionary

Golgi, apparatus - A complex of irregular structures consisting of parallel membranes in cytoplasm cells. Basically, this is a packaging factory of cells. Secretor cells cover their product with a membrane produced by the Golgi apparatus, after moving to the outer ... ... Dictionary Psychology

Golgi Complex (named K. Goldzhi), cellulla cells involved in the formation of products of its livelihoods (various secrets, collagen, glycogen, lipids, etc.), in the synthesis of glycoproteins. * * * Golgi Machine Golgi Device ... ... encyclopedic Dictionary

The Golgi apparatus is a single-dimmable, microscopic eukaryotic cell organhella, which is designed to complete the processes of cell synthesis and provides the derivation of the formed substances.

The study of the structural components of the Golge Complex began in 1898 by the Italian histologist-histologist Camillo Golgi, in honor of Him Orgella and was named. The study of the organo was held for the first time in the composition of the nervous cell.

The structure of the Golgi complex

In the lamellar complex (Machine of Golgi) there are three parts:

• Cis-tank - located near the nucleus, constantly interacts with the granular endoplasmic network;
• medial-tank or intermediate part;
• trans-tank - distant from the nucleus, gives tubular branching, forming a trans-network of Golgi.

Plate complex in cells of different nature and even at various stages of differentiation of one cell, sometimes has distinctive features in the structure.

Characteristic signs of the Golgi apparatus

It has a type of stack, which consists of three to eight tanks, a thickness of about 25 nm, they are flattened in the central part and expand in the direction to the periphery, resemble the stack of inverted plates. The surfaces of the tanks are adjacent to each other very tight. From the peripheral part, small membrane bubbles are buded.

Human cells have one, less than a pair of stacks, and plant cells may contain several such formations. The totality of tanks (one stack) together with the surrounding bubbles is called a docyoma. Several docyomes can communicate with each other by forming a network.

Polarity - the presence of a cis-side pointing to the EPS and the nucleus, where the merger of the vesicle and the trans-side, as directed to the cellular shell, (this feature is well traced in the cells of secreting organs).

Asymmetric - The side located closer to the core of the cell (proximal pole) accommodates the "immature" proteins, vesicles disconnected from EPS, the trans-side (distal, mature pole) contains already modified proteins.

When destroying alien agents of the plate complex, the Golgji apparatus is separated into separate parts, but its basic functions are saved. After the resumption of the microtubule system, which were chaotic scattered in the cytoplasm, the part of the device are collected, and again turn into a normally functioning plate complex. The physiological separation occurs under normal conditions of cellularity of cells during indirect division.

EPS and Golgji Complex

Eps - Is it part of the Golgji complex?

Definitely no. The endoplasmic network is an independent membrane organella, which is built from a system of closed tubules, tanks formed by a continuous membrane. The main function is the synthesis of proteins, with the help of ribosomes placed on the surface of the granular EPS.

There are a number of similar signs between the EPS and the Golgji apparatus:

• These are intracellular formations, drawn from the cytoplasm of the membrane;
• separated membrane bubbles that are filled with organic synthesis products;
• together form a single synthesizing system;
• in secretion cells have the greatest size and high level development.

What are the walls of the endoplasmic network and the Golgi complex?

The walls of the EPS and the Golgji apparatus are presented in the form of a single-layer membrane. These organelles together with lysosomes, peroxyms and mitochondria are combined into a group of membrane organoids.

What happens in the Golgjie complex with hormones and enzymes?

The endoplasmic network is responsible for the synthesis of hormones, the production of hormonal substances is produced on the surface of its membrane. The synthesized hormones come to the Golgji complex, they accumulate here, then recycling and eliminating them out. Therefore, in the cells of endocrine organs there are large-sized complexes (up to 10 microns).

Functions of the Golgi complex

Protelyolis protein substances, which leads to the activation of proteins, so the proinsulin goes into insulin.

Provides transport from the EPS synthesis products.

The most important feature of the Golgji complex is considered to eliminate the synthesis products from the cell, so it is also called the cell vehicle.

Synthesis of polysaccharides, such as pectin, hemicellulose, which is part of the membranes of plant cells, the formation of glycosaminoglycans, one of the components of the intercellular fluid.

In the tanks of the lamellar complex goes ripening of protein substancesnecessary for secretion, transmembrane proteins of the cell membrane, lysosome enzymes, etc. In the process of ripening, proteins are gradually moved by the organoid departments, in which their formation is completed and glycosylation and phosphorylation occurs.

The formation of lipoptretoid substances. Synthesis and accumulation of mucous substances (mucin). The formation of glycolipids, which are part of the membrane glycicalis.

Provides proteins in three directions: to lysosomes (the transfer is controlled by the enzyme - mannose-6-phosphate), to membranes or intracellular medium, and to the intercellular space.

Together with grainy EPS forms lysosomesBy merging the bombarded vesicles with autolytic enzymes.

Exocitosis transfer - Vesicul, approaching the membrane, is embedded in it and leaves its contents from the outside of the cell.

Summary table of functions of the Golgi complex

Structural unit	Functions
Cis-tank	Capture of synthesized EPS proteins, membrane lipids
Middle tanks	Posttranslation modifications associated with the transfer of acetylglucosamine.
Trans-tank	Glycosylation, the addition of galactose and sialic acid, is completed, the substances are sorted for further transport from the cell.
Bubbles	They are responsible for the transfer of lipids, proteins in the Golgi apparatus and between tanks, as well as to eliminate synthesis products.

Organoid. - Permanent, necessarily present, cell components performing specific functions.

Endoplasmic reticulum

Endoplasmic Network (EPS), or endoplasmic reticulum (EPR)- single-dimmable organoid. It is a system of membranes forming "tanks" and channels connected to each other and limiting a single internal space - an EPS cavity. The membranes on the one hand are associated with the cytoplasmic membrane, on the other, with the outer nuclear membrane. There are two types of EPS: 1) a rough (granular), containing ribosome on its surface, and 2) smooth (agranular), whose membranes are not carried by ribosomes.

Functions: 1) Vehicles of substances from one piece of cells to another, 2) Separation of cytoplasm cells for compartments ("compartments"), 3) Synthesis of carbohydrates and lipids (smooth EPS), 4) protein synthesis (rough EPS), 5) Place of formation of the Golgi apparatus .

Or golgi complex- single-dimmable organoid. It is a stack of flattened "tanks" with extended edges. The system of small single-mounted bubbles is connected with them (Golgi bubbles). Each stack usually consists of 4-x-6 "tanks", is a structural-functional unit of the Golgi apparatus and is called the docyoma. The dontyom number in the cell ranges from one to several hundred. In plant cells, disosome are separate.

The Golgi apparatus is usually located near the cell nucleus (in animal cells often near the cellular center).

Functions of the Golgi apparatus: 1) accumulation of proteins, lipids, carbohydrates, 2) Modification of the organic substances received, 3) "Packaging" in membrane bubbles of proteins, lipids, carbohydrates, 4) secretion of proteins, lipids, carbohydrates, 5) Synthesis of carbohydrates and lipids, 6) lysosomes. The secretory function is the most important, so the Golgi apparatus is well developed in secretory cells.

Lysosomes

Lysosomes - Single-grams organoids. Present small bubbles (diameter from 0.2 to 0.8 microns) containing a set of hydrolytic enzymes. Enzymes are synthesized on rough EPS, moved to the Golgi apparatus, where their modification and packaging occurs in the membrane bubbles, which, after separation from the Golgi apparatus, become actually lysosomes. Lysosome can contain from 20 to 60 different types of hydrolytic enzymes. Splitting substances with the help of enzymes call lysis.

Distinguish: 1) primary lysosomes, 2) secondary lysosomes. The primary are called lysosomes, departed from the Golgi apparatus. Primary lysosomes are a factor that provides exocytosis of enzymes from the cell.

Secondary are called lysosomes formed by the fusion of primary lysosomes with endocytosis vacuoles. In this case, there are digestion of substances that entered the cell by phagocytosis or pinocytosis, therefore they can be called digestive vacuoles.

Autofagi. - The process of destroying unnecessary cells of structures. First, the structure to be destroyed is surrounded by a single membrane, then the resulting membrane capsule merges with the primary lysosome, as a result, a secondary leasing (autophagic vacuol) is also formed, in which this structure is digested. Digestion products are absorbed by cytoplasm cells, but part of the material remains untouched. The secondary lysosome containing this undigested material is called a residual body. By exocytosis, unauthorized particles are removed from the cell.

Autoliz - self-destruction of the cell that occurs due to the release of the contents of lysosomes. Normally autolysis takes place in metamorphosis (the disappearance of the tail from the head of frogs), the involution of the uterus after childbirth, in the foci of the tissue.

Functions lysosomes: 1) intracellular digestion of organic substances, 2) the destruction of unnecessary cellular and non-cellular structures, 3) participation in the reorganization processes of cells.

Vacuole

Vacuole - Single-grams organides are "capacity" filled aqueous solutions Organic I. inorganic substances. Eps and the Golgi apparatus take part in the formation of vacules. Young vegetable cells contain many small vacuoles, which then, as cell differentiation and differentiation, the cells are merged with each other and form one large central Vakolol.. The central vacuole can take up to 95% of the volume of the mature cell, the kernel and organoids are pushed out to the cellular shell. The membrane bounding the vegetable vacuol is called a tonoplast. Liquid filling vegetative vacuole, called cell juice. The composition of the cell juice includes water-soluble organic and inorganic salts, monosaccharides, disaccharides, amino acids, finite or toxic substance metabolic products (glycosides, alkaloids), some pigments (anthocyans).

In animal cells there are small digestive and autophagic vacuoles related to a group of secondary lysosomes and containing hydrolytic enzymes. Unicellular animals have more contractile vacuoles that perform the function of aczoregulation and selection.

Vacuole Features: 1) accumulation and storage of water, 2) Regulation of water-salt metabolism, 3) Maintenance of tour pressure, 4) accumulation of water-soluble metabolites, spare nutrients, 5) coloring of colors and fruits and attracting the pollinators and distributors of seeds, 6) See the functions of lysosomes.

The endoplasmic network, the Golgi, Lizosomes and Vacuoles apparatus form unified vacuolar cell network, some elements of which can go to each other.

Mitochondria

1 - outer membrane;
2 - internal membrane; 3 - matrix; 4 - Crista; 5 is a multimenme system; 6 - Ring DNA.

Form, dimensions and number of mitochondria vary extremely. In the form of mitochondria, there may be rolled, rounded, spiral, cupid, branched. The length of mitochondria ranges from 1.5 to 10 microns, diameter - from 0.25 to 1.00 microns. The amount of mitochondria in the cell can reach several thousand and depends on the metabolic activity of the cell.

Mitochondria is limited to two membranes. Outdoor membrane Mitochondria (1) Smooth, internal (2) forms numerous folds - crysto (four). Crystys increase the surface area of \u200b\u200bthe inner membrane, on which the multimenza systems (5) are located involved in the synthesis of ATP molecules. The internal space of mitochondria is filled with matrix (3). The matrix contains ring DNA (6), specific IRNK, ribosomes of prokaryotic type (70s-type), Krebs cycle enzymes.

Mitochondrial DNA is not associated with proteins ("naked"), attached to the inner membrane of mitochondria and carries information about the structure of approximately 30 proteins. For the construction of mitochondria, much more proteins are required, so information on most mitochondrial proteins is contained in nuclear DNA, and these proteins are synthesized in the cytoplasm of the cell. Mitochondria is capable of autonomously multiply by dividing in two. Between the outer and inner membranes is located proton tankwhere H + accumulation occurs.

Functions Mitochondria: 1) synthesis ATF., 2) oxygen cleavage of organic substances.

According to one of the hypothesis (theory of symbiogenesis), mitochondria occurred from ancient free-lived aerobic prokaryotic organisms, which accidentally penetrating the host cell, then formed a mutually beneficial symbiotic complex with it. The following data is evidenced in favor of this hypothesis. First, the mitochondrial DNA has the same features of the structure as well as DNA of modern bacteria (closed in the ring, not related to proteins). Secondly, mitochondrial ribosomes and ribosomes of bacteria belong to one type - 70s-type. Thirdly, the Mitochondrial division mechanism is similar to that bacteria. Fourth, the synthesis of mitochondrial and bacterial proteins is suppressed by the same antibiotics.

Platids

1 - outer membrane; 2 - internal membrane; 3 - Strom; 4 - thylacoid; 5 - grana; 6 - Lammella; 7 - grain starch; 8 - lipid drops.

Lands are characteristic only for plant cells. Distinguish three main types of plastic: leukoplasts - colorless plastides in the cells of unpainted parts of plants, chromoplasts - painted plasts usually yellow, red and orange colors, chloroplasts - green plasts.

Chloroplasts. In the cells of higher plants, chloroplasts have a two-way lens. The length of chloroplasts ranges from 5 to 10 microns, diameter - from 2 to 4 microns. Chloroplasts are limited to two membranes. The outer membrane (1) is smooth, internal (2) has a complex folded structure. The smallest fold is called thylacoid (four). Telakoid group laid like a stack of coins is called grana (five). In chloroplast, contains an average of 40-60 graffitions. Graars are associated with each other with compiled channels - lammella (6). Tylacoid membranes are built-in photosynthetic pigments and enzymes that provide synthesis of ATP. The main photosynthetic pigment is chlorophyll, which determines the green color of chloroplasts.

The internal space of chloroplasts is filled stroma (3). In the stroma there are ring "naked" DNA, 70S-type ribosomes, Calvine Cycle Enzymes, Starch Grain (7). Inside each thylacoid is a proton tank, H + accumulation occurs. Chloroplasts, as well as mitochondria, are capable of autonomous reproduction by dividing in two. They are contained in the cells of the green parts of higher plants, especially many chloroplasts in the leaves and green fruits. Chloroplasts lower plants Call chromatophoras.

Chloroplast function: photosynthesis. It is believed that chloroplasts occurred from ancient endosimbiotic cyanobacteria (symbogenesis theory). The basis for such an assumption is the similarity of chloroplasts and modern bacteria for a number of signs (annular, "naked" DNA, 70s-type ribosomes, a method of reproduction).

Leukoplasts. The form varies (spherical, rounded, cups, etc.). The leukoplasts are limited to two membranes. The outer membrane is smooth, the inner forms small thylacoids. In the stroma there are ring "naked" DNA, 70s-type ribosomes, synthesis enzymes and hydrolysis of spare nutrients. Pigments are absent. Especially many leukoplasts have cells of underground organs of the plant (roots, tubers, rhizomes, etc.). Function of leukoplasts: Synthesis, accumulation and storage of spare nutrients. Amyloplasts - leukoplasts that synthesize and accumulate starch, elayoplasts - oils, proteinoplasts - Proteins. In the same leukoplast can accumulate different substances.

Chromoplasts. Limited by two membranes. The outer membrane is smooth, inner or also smooth, or forms single tylacoids. In the stroma there are ring DNAs and pigments - carotenoids that give chromoplasts yellow, red or orange color. The shape of the accumulation of pigments is different: in the form of crystals, dissolved in lipid drops (8) and others are contained in the cells of mature fruits, petals, autumn leaves, rarely root. Chromoplasts are considered the final stage of the development of the plastic.

Function of chromoplasts: Coloring colors and fruits and thereby attracting pollinators and seed distributors.

All types of plastids can be formed from precipitide. Proplastids - Small organoids contained in meristematic tissues. Since the plastids have a general origin, interconnections are possible between them. The leukoplasts can turn into chloroplasts (greening potato tubers in light), chloroplasts - in chromoplasts (yellowing of leaves and redness of the fruit). The conversion of chromoplasts in leucoplasts or chloroplasts is considered impossible.

Ribosomes

1 - a large subunit; 2 - Small subunit.

Ribosomes - non-smuggled organides, diameter of about 20 nm. Ribosomes consist of two subunits - large and small, which can dissociate. Chemical composition of ribosomes - proteins and RRNA. RRNA molecules are 50-63% of the mass of ribosomes and form its structural framework. Two types of ribosomes are distinguished: 1) eukaryotic (with a whole ribosome sedimentation constants - 80s, a small subunit - 40s, large - 60s) and 2) prokaryotic (70s, 30s, 50s, respectively).

As part of a ribosome of eukaryotic type 4 RRNA molecules and about 100 protein molecules, prokaryotic type - 3 RRNA molecules and about 55 protein molecules. During the biosynthesis, the ribosoma protein can "work" by one or unite into the complexes - polyribosomes (polisomas). In such complexes, they are connected with each other by the same INK molecule. Procarniotic cells have only 70s-type ribosomes. Eukaryotic cells have ribosomes like 80s-type (grouse membranes EPS, cytoplasma) and 70s-type (mitochondria, chloroplasts).

The eukaryot ribosome subunits are formed in the nucleoline. Combining subunits to a whole ribosome occurs in the cytoplasm, as a rule, during the protein biosynthesis.

Ribosoma function: Assembly of the polypeptide chain (protein synthesis).

Cytoskeleton

Cytoskeleton Educated by microtubes and microfilaments. Microtubule - cylindrical unbranched structures. The length of the microtubule ranges from 100 μm to 1 mm, the diameter is approximately 24 nm, the wall thickness is 5 nm. The main chemical component is a tubulin protein. Microtubules are destroyed under the influence of colchicine. Microfilaments - threads with a diameter of 5-7 nm, consist of a actin protein. Microtubule and microfilaments form complex interlacing in the cytoplasm. Functions of the cytoskeleton: 1) Definition of the shape of the cell, 2) support for organoids, 3) the formation of the spindle of the division, 4) participation in the movements of the cell, 5) the current organization of the cytoplasm.

Includes two centrioles and centrofer. Centril It is a cylinder, the wall of which is formed by nine groups of three spilled microtubules (9 triplets) interconnected through certain intervals of cross-shyshivs. Centrioles are combined into a couple where they are located at right angles to each other. Before dividing the cells, the centrioles diverge to the opposite poles, and a subsidiary of a centril arises near each of them. They form spine divisions that contribute to the uniform distribution of genetic material between the daughter cells. In the cells of higher plants (viced, coated brine), the cell center of the centrioleum has no. Centrioli refers to the self-reproducing cytoplasm organoids, they arise as a result of the duplication of already available centrioles. Functions: 1) Ensuring the discrepancy of chromosomes to the cell poles during mitosis or meiosis, 2) the center of organizing the cytoskeleton.

Motion organides

Present not in all cells. Equipment of the movement include cilia (infusoria, respiratory epithelium), flagella (flagelon, spermatozoa), false and tables (nuts, leukocytes), myofibrils (muscle cells), etc.

Flagella and cilia - organoids of the filamentine form are an axonsee, limited membrane. Axonma - cylindrical structure; The wall of the cylinder is formed by nine pairs of microtubules, there are two single microtubules in its center. At the base of the axes there are basal calves, represented by two mutually perpendicular centrioles (each basal caller consists of nine triplets of microtubules, there is no microtubule in its center). The flank length reaches 150 μm, cilia several times shorter.

Miofibrils Consist of actin and alone myophilaments that reduce muscle cells.

Go to lectures number 6. "Eukaryotic cell: cytoplasm, cell shell, structure and function of cell membranes"