From the moment the land became a full-fledged planet, life began to emerge on it. First of all, cells appeared - building material for all living things. Writing now a variety of life forms not only makes his eyes, but also makes you think about the complexity of evolutionary processes. Despite the dissimilarity of organisms, the cells from which they consist, go to each other. But scientists still found differences and shared them into two extensive groups: prokaryotes and eukaryotes. At the same time, viruses are classified separately, and science can not yet decide whether these organisms live.

Microworld among us

Now people live in a big world, knowing that there is a small universe, sising by various microorganisms: some of them are loyal to a person, others - are dangerous.

We are talking about the variety of bacterial life. Procarniotes are bacteria. Whereas more complex eukaryotes are schematically divided into several kingdoms: plants, animals, mushrooms and mucus.

Bacteria (prokaryotes) differ in the following features:

single, nuclear-free cell (nucleoid formation);
binary division;
distinction of forms, quantities;
availability or lack of organelle.

Bacteria-prokaryotes are divided into convolutions (vibrions), rolling-shaped (bacillos), similar to Corkscrew (Spirilla) and spherical (cocci). Moves are moved either by mucus, or using flagella.

Flagship Evolution

It has been proven that prokaryotes appeared first. If we translate the word from the Greek language, then "prokaryotes" is the cells in which the kernel is missing.

But in such a categorical definition it is necessary to make some amendments. Prokaryotes contain structures similar to a kernel that have no membranes that are in the cytoplasmic fluid. Such unformed kernels were called nucleoids. It is in them there is a modest amount of cell genetic information.

There were simple cells about 35 million centuries ago. Following this fantastic figure, it can be argued that prokaryota is the first live matter at the then young land.

More. Volumeful. More difficult

By contacting the knowledge of the ancient Greeks, it can be found out that "eukaryota" means "possessing the core", and this statement fully corresponds to reality.

Such cells, expressing modern tongue, are more advanced. The presence of a full-fledged nucleus plays this not the last role. Fully decorated kernel with two layers of the membrane reliably protects the genetic code contained in it. Partly DNA molecules are outside the nucleus, in chloroplasts and mitochondria. Among other things, eukaryotes are much more nuclear-free in size and volume.

Eukarotes appeared approximately two billion years later, after the occurrence of elementary prokaryotes. It can be said that prokarytam belongs to the progenitors are true nuclear.

Arming a microscope

Procarniot cells are not only much less than eukaryotes, they differ significantly to their structural features.

Prokaryotes and eukaryotes are distinguished by the unequal complexity of the structure, where the prokaryotic cell is much simpler.

Mucous capsule. The functions of the capsule are reduced to the protection of the cell: it protects from drying and the action of antibodies. It consists mainly of polysaccharides, with polypeptide inclusions.
Cell wall. Thanks to the murein, from which this shell is consisting, this structural component is characterized by rigidity. Perform a triple function: protective, transport, reliably fixes the shape and integrity of the cell.
Cell protopast. Due to the difference in the growth of the protoplast and the outer cell membrane, invagination occurs - internal deflection. Such processes allow for the form of organoids called mesosomes. They perform the necessary cellular functions. While the ribosomes are assigned a protein synthesis mission.
Nucleoid. Extracted, ellipsoidal structure that performs the role of the kernel. It is not separated from the cytoplasm, so scientists do not classify it as a full core. Additional DNA information may be very small particles - Plasmids.
Optional organelles. Presented by various intersions: sulfur, polyphosphates, oil, glycogen, polysaccharide grains. Also, organodes include flagellas that help the cell move, and saw protein inclusions that perform the attachment function.

If we can talk about the simplicity of the structure applies to such a complex living design, like a cell, then definitely prokaryotes are simple structures.

The structure of truly nuclear

Eukarotes, on the contrary, have a complex structure. The arising, on the assumptions of the scientist of the world, on the basis of prokaryotes, they contain more advanced structures.

Membrane. Performs selective and protective function.
Cell wall, or glycolix (in animals). In mushrooms and plants, it plays a stabilizing and preserving role. Consists of chitin and cellulose fibers, respectively. Animals are capable without a cell wall due to the action of other mechanisms.
Cytoplasm. It consists of a solution of inorganic and organic substances under the general name of the hyaloplasma. The main component capable of carrying out chemical reactions is a protein.
Core. The most important component of the cells. It stores genetic information in chromosomes. The core is protected by two membranes.
Organoishes. Located on the territory of hyaloplasm and are represented by many items. The most important components are mitochondria, the Golgi complex, chloroplasts, lysosomes, ribosomes.

Eukarot core can be divided into two ways: mitosis and meyosis. This is extremely important for the development and work of the cell.

Brief analysis

The differences between the two groups can be systematized and described in a language that is understandable to all. Especially since the cells of prokaryotes and eukaryotes will obviously differ.

comparison table

Signs	Procarniotic cells	Eukaryotic cells
Chronological niche	3.5 billion	one and a half billion years old
Value	0.01 mm	0.1 mm (more than 1000 times)
Genome	located in a nucleoid, decorated in the form of an ellipse	located in a kernel containing chromosome; Partly DNA is located in mitochondria and chloroplasts
Organoid.	sometimes meet, but in small quantities and silent	in a set; plasts and mitochondria have their genome and reproduction ability; Each organella performs a clearly defined function
Method of division	binary (in half)	mitosis: division with the preservation of chromosomes; Meiosis: Two Chromosomes Two
Traffic	sometimes the mucus helps, more often - protein threads	with the help of flagellas (complex, multilayer processes) and cilia
Phenomenon phagocytosis	absent	presumably appeared to ensure the livelihood of a large cell; Thanks to this phenomenon, predators appeared

Features of prokaryotov

After the electron microscope appeared, it became possible to differentiate eukaryotes and prokaryotes, as well as study them in more detail.

The main difference between the milking cells is that prokaryotes are bacteria that are present everywhere: in the human body, water, air, plants. Very many bacteria is in the soil. They live even in atomic reactors!

Despite the minor sizes, prokaryotes are custodians of coded genetic information affecting the vital activity of organisms. For example, in plasmids, which are in free swimming among the water of a cytoplasmic cocktail, a gene affecting the stability of the bacteria to medicines.

In addition, the simplicity of the organization does not interfere with the bacteria flourish, actively repel, along with more complex eukaryotes.

Dilemma: benefit or harm

The value of eukaryotov is not subject to doubt: thanks to them there have been a variety of forms of life. But with bacteria is not so unequivocal. On the one hand, thanks to the microorganisms that are in the intestine, people can successfully digest food, synthesize and absorb vitamins. Also prokaryotes, covering the skin or mucosa, perform a protective function.

Some bacteria are necessary for the production of cheeses, sour cream, acidic cabbage. Interestingly, the bacteria that possess the action similar to antibiotics.

On the other hand, certain types of non-surfactants can cause diseases or spoil products. They are capable not only to distinguish toxins, but also to destroy the cells of the occupied organism.

Therefore, for sure to talk about the benefits or harm of prokaryotov it is impossible: it all depends on their types. But in any case, this smallest cells, humanity is required by its existence.

The structure of eukaryotic and prokaryotic cells. Eukaryotic cell. The structure of the prokaryotic cell. Comparison of prokaryotic and eukaryotic cells.

Two types of cells are known for modern and fossil organisms: prokaryotic and eukaryotic. They are so sharply different from the characteristics of the structure that it served to allocate two headguards of the living world - prokaryotm, i.e. Military, and eukaryotes, i.e. These nuclear organisms. Intermediate forms between these largest taxams are still unknown.

The main features and differences in prokaryotic and eukaryotic cells (table):

Signs	Procarniot	Eukaryota
Nuclear membrane	Absent	Available
Plasma membrane	Available	Available
Mitochondria	Absent	Available
EPS	Absent	Available
Ribosomes	Available	Available
Vacuole	Absent	There are (especially characteristic of plants)
Lysosomes	Absent	Available
Cell wall	There is, consists of a complex heteropolymer substance	None in animal cells, in vegetable consists of cellulose
CAPSULE	If available, then consists of protein and sugar compounds	Absent
Golgi complex	Absent	Available
DIVISION	Simple	Mitoz, Amitiosis, Meiosis

The main difference of prokaryotic cells from eukaryotic lies in the fact that their DNA is not organized in chromosome and is not surrounded by a nuclear sheath. Eukaryotic cells are much more complicated. Their DNA associated with the protein is organized in chromosomes, which are located in a special education, essentially the largest organoid cells - the kernel. In addition, the extraordinary active content of such a cell is divided into separate compartments using an endoplasmic network formed by an elementary membrane. Eukaryotic cells are usually larger than prokaryotic. Their sizes vary from 10 to 100 μm, while the sizes of prokary cell cells (different bacteria, cyanobacteria - blue-green algae and some other organisms), as a rule, do not exceed 10 microns, often by 2-3 microns. In the eukaryotic cell, genera of genes - chromosomes are located in a morphologically decorated core, degraded from the rest of the membrane cell. In exceptionally thin, transparent preparations, living chromosomes can be seen using a light microscope. They are most often studied on fixed and painted drugs.

Chromosomes consist of DNA, which is located in a complex with proteins - Histons, rich amino acids arginine and lysine. Histons make a significant part of the mass chromosomes.

A eukaryotic cell has a variety of permanent intracellular structures - organides (organelles), absent in the prokaryotic cell.

Procarniotic cells can be divided into equal parts with a drawing or kill, i.e. Form a smaller daughter cell than maternal, but never divided by mitosis. The cells of eukaryotic organisms, on the contrary, are divided by mitosis (excluding some very archaic groups). The chromosome at the same time "split" longitudinally (more precisely, each DNA thread reproduces its likeness), and their "halves" - chromatids (full-fledged copies of DNA threads) diverge to groups to the opposite cell poles. Each of the cells formed then receive the same chromosoma set.

The ribosomes of the prokaryotic cell are sharply different from the ribosoma eukaryota in magnitude. A number of processes inherent in the cytoplasm of many eukaryotic cells - phagocytosis, pinocytosis and cyclicosis (rotational movement of the cytoplasm) - not detected in prokaryot. The prokaryotic cell in the process of metabolism does not require ascorbic acid, but eukaryotic cannot do without it.

Movable forms of prokaryotic and eukaryotic cells differ significantly. Prokaryotes have engine devices in the form of flagella or cilia, consisting of flag relax. Motor adaptations of movable eukaryotic cells received the name of undulipodies, fixing in a cell using special taurus kinetos. Electronic microscopy revealed the structural similarity of all abdominal eukaryotic organisms and sharp differences from the flavors of prokaryotes

1. The structure of the eukaryotic cell.

Cells forming animal and plant fabrics are significantly different in shape, sizes and internal structure. However, they all detect the similarity in the main features of the processes of vital activity, metabolism, in irritability, growth, development, ability to variability.
The cells of all types contain two main components, closely interconnected, cytoplasm and core. The kernel is separated from the cytoplasm of a porous membrane and contains nuclear juice, chromatin and nucleolo. The semi-liquid cytoplasm fills the entire cage and is permeated with numerous tubules. Outside it is covered with a cytoplasmic membrane. It has specialized structures-organoids, Present in the cell constantly, and temporary education - inclusion. Membrane organoids : Outdoor cytoplasmic membrane (HCM), endoplasmic network (EPS), Machinery, Lizosomes, Mitochondria, and Lizosomes. The basis of the structure of all membrane organoids is the biological membrane. All membranes have a fundamentally united structure of the structure and consist of a double layer of phospholipids, into which the protein molecules are immersed from different sides of the IVA. Organoid membranes differ from each other only by the sets of proteins that are included in them.

Cytoplasmic membrane. In all plant cells, multicellular animals, in the simplest and bacteria, the three-layer cell membrane: the outer and inner layers consist of protein molecules, the average - from the lipid molecules. It limits the cytoplasm from the external environment, surrounds all cell organides and is a universal biological structure. In some cells, the outer shell is formed by several membranes, firmly adjacent to each other. In such cases, the cell shell becomes dense and elastic and allows you to preserve the shape of the cell, such as, for example, the eggs and infusories of the shoes. In most vegetable cells, in addition to the membrane, there is still a thick cellulose sheath outside. cell wall. It is well distinguishable in the usual light microscope and performs a reference function due to the rigid outer layer that gives the cells a clear form.
On the surface of the membrane cells, elongated grows - microvilles, folds, pensions and protrusion, which increases the suction or excretory surface increases many times. With the help of membrane grows, the cells are connected to each other in the tissues and organs of multicellular organisms, on the folds of the membranes are located a variety of enzymes involved in the exchange of substances. The exciting cell from the environment, the membrane regulates the direction of diffusion of substances and at the same time performs active transfer of them inside the cell (accumulation) or outward (selection). Due to these properties of the membrane, the concentration of potassium ions, calcium, magnesium, phosphorus in the cytoplasm is higher, and the sodium concentration and chlorine is lower than in the environment. Through the pores of the outer membrane from the external medium inside the cells penetrate ions, water and fine molecules of other substances. Penetration into a cell relative to large solid particles is carried out by phagocytosis (from Greek. "Pago" - devout, "pitted" - cage). In this case, the outer membrane at the point of contact with the particle begins inside the cell, carried away the particle into the depth of the cytoplasm, where it is subjected to enzymatic cleavage. Similarly, drops of liquid substances fall into the cell; Their absorption is called pinocytosis (from Greek. "Pinot" - Pugh, "Citos" - a cell). Outer cell membrane performs other important biological functions.
Cytoplasm 85% consists of water, by 10% - from proteins, the remaining volume is accounted for by lipids, carbohydrates, nucleic acids and mineral compounds; All these substances form a colloidal solution close to glycerin's consistency. The cell colloidal substance, depending on its physiological state and the nature of the exposure to the external environment, has properties and fluids, and an elastic, more dense body. The cytoplasm is permeated by channels of various shapes and the values \u200b\u200bthat were called endoplasmic network. Their walls are membranes, closely in contact with all cells of the cell and components together with them a single functional-structural system for making metabolism and energy and moving substances inside the cell.

In the walls of the tubules are the smallest grains - granules, called ribosomes. Such a network of tubules is called granular. Ribosomes can be located on the surface of the tubules disparately or form complexes from five to seven and more ribosomes called polyesomas. Other channels of granules do not contain, they constitute a smooth endoplasmic network. On the walls there are enzymes involved in the synthesis of fats and carbohydrates.

The inner cavity of the tubules is filled with the products of the vital activity of the cell. Intracellular tubules, forming a complex branching system, regulate the movement and concentration of substances, separated various organic substance molecules and their stages, synthesis. On the inner and outer surface of the enzyme-rich membranes, proteins, fats and carbohydrates are made, which are either used in metabolism, or accumulate in cytoplasm as inclusions, or outward.

Ribosomes There are found in all types of cells - from bacteria to cells of multicellular organisms. These are rounded tales consisting of ribonucleic acid (RNA) and proteins in almost equal ratio. Their composition certainly includes magnesium, the presence of which supports the structure of Ribosomes. Ribosomes can be associated with the membranes of the endoplasmic network, with an outer cell membrane or freely lie in the cytoplasm. They are in the synthesis of proteins. Ribosomes other than cytoplasm are found in the core core. They are formed in the nucleoline and then enter the cytoplasm.

Golgi complex In plant cells, has the appearance of individual calves surrounded by membranes. In animal cells, this organoid is represented by tanks, tubules and bubbles. The membrane tubes of the Golgji complex from the channel of the endoplasmic network receive the cells of the cells of the cell, where they are chemically rebuilt, are compacted, and then they are moving to the cytoplasm or are either used by the cell itself, or are derived from it. In the tanks of the Golgi complex, the synthesis of polysaccharides occurs and their association with proteins, as a result of which glycoproteins are formed.

Mitochondria - Small chopstick shape, limited to two membranes. Numerous folds are departed from the inner membrane of mitochondria - Crysts, there are various enzymes on their walls, with the help of the synthesis of high-energy substance - adenosinerythrifosphoric acid (ATP). Depending on the activity of the cell and external influences of mitochondria, they can move, change their dimensions, shape. Ribosomes, phospholipids, RNA and DNA are found in mitochondria. With the presence of DNA in mitochondria, the ability of these organoids to reproduction by forming a hauling or killing during the cell division period, as well as the synthesis of parts of mitochondrial proteins.

Lysosomes - Small oval formations, limited membrane and scattered throughout the cytoplasm. There are in all cells of animals and plants. They arise in the extensions of the endoplasmic network and in the Golgi complex, are filled here with hydrolytic enzymes, and then separated and entered into the cytoplasm. In the usual "conditions of lysosomes digest particles entering the cell by phagocytosis, and organoids of die cells. Lysis products are derived through the Lizosoma membrane in a cytoplasm, where they are included in the new molecules. When the lease membrane is broken, the enzymes come to the cytoplasm and digest its contents, causing Cell death.
Platids There are only in vegetable cells and are found, in most green plants. In plastids, organic substances are synthesized and accumulated. There are plastides of three species: chloroplasts, chromoplasts and leucoplasts.

Chloroplasts - Green plasts containing green chlorophyll pigment. They are in the leaves, young stems, immature fruits. Chloroplasts are surrounded by a double membrane. In higher plants, the inner part of chloroplasts is filled with a semi-liquid substance, in which plates are laid parallel to each other. Paired membranes of plates, merging, form stacks containing chlorophyll. In each stack of chloroplasts of higher plants alternate the layers of protein molecules and lipid molecules, and the chlorophyll molecules are located between them. Such a layered structure provides a maximum of free surfaces and facilitates the capture and transfer of energy in the process of photosynthesis.
Chromoplasts - The plastids containing plant pigments (red or brown, yellow, orange). They are concentrated in the cytoplasm of flowers of flowers, stalks, fruits, plant leaves and give them an appropriate color. Chromoplasts are formed from leucoplasts or chloroplasts as a result of accumulation of pigments carotenoids.

Telecoplasts - colorful The plasts located in the unpainted parts of the plants: in the stems, roots, bulbs, etc. In the leukoplasts of some cells accumulate grains of starch, in leucoplasts of other cells - oils, proteins.

All plastdoms arise from their predecessors - a precipitide. They revealed DNA, which controls the reproduction of these organoids.

Cell center or centrosome, plays an important role in division, cells and consists of two centrioles . It occurs in all cells of animals and plants, except for the flowering, lower mushrooms and some simplest. Centrioles in dividing cells take part in the formation of the separation of division and are located on its poles. In a dividing cell, the cell center is first divisible, simultaneously produces achromatine spindle, orienting chromosomes when they are discrepressed to the poles. The subsidiaries are departed on one centriole.
Many vegetable and animal cells have special purpose organides: cilia, performing the function of movement (infusoria, cells of the respiratory tract), flagella (the simplest unicellular, men's sexes in animals and plants, etc.).

Inclusion -temporary elements arising in a cell at a certain stage of its livelihoods as a result of a synthetic function. They are either used or derived from the cell. Inclusions are also spare nutrients: in starch vegetable cells, fat droplets, proteins, essential oils, many organic acids, salts of organic and inorganic acids; in animal cells - glycogen (in liver and muscle cells), fat drops (in subcutaneous tissue); Some inclusions accumulate in cells as garbage - in the form of crystals, pigments, etc.

Vacuole - These are cavities limited to the membrane; Well expressed in plants cells and are available at the simplest. There are in different parts of the extensions of the endoplasmic network. And gradually separated from it. The vacuoles support the tour pressure, the cellular or vacuolar juice is concentrated in them, the molecules of which determine its osmotic concentration. It is believed that the initial products of synthesis are soluble carbohydrates, proteins, pectins, etc. - accumulate in the tanks of the endoplasmic network. These clusters are the primitive vacuoles.
Cytoskeleton . One of the distinctive features of the eukaryotic cell is the development of skeletal formations in its cytoplasm in the form of microtubules and bunches of protein fibers. The elements of the cytoskeleton are closely connected with the outer cytoplasmic membrane and the nuclear sheath, form complex weave in the cytoplasm. Cytoplasm support elements define the shape of the cell, ensure the movement of intracellular structures and move the entire cell.

Core Cells plays a major role in its livelihoods, with its cell removal stops its functions and dies. In most animal cells one core, but there are also multi-core cells (liver and muscles of man, mushrooms, infusories, green algae). Mammals erythrocytes are developing from predecessor cells containing the kernel, but mature red blood cells lose it and live long.
The kernel is surrounded by a double membrane, permeated by pores, through which it is closely related to the channels of the endoplasmic network and cytoplasm. Inside the core is located chromatin - Spiralized sections with chromosomes. In the period of cell division, they turn into row-shaped structures, well distinguishable in the light microscope. Chromosome is a complex protein complex with DNA, called nucleoproteide.

The functions of the core consist in the regulation of all the lifestarts of the cell, which it exercises with the help of DNA and RNA material carriers of hereditary information. During preparation for the division of DNA cells, the chromosome mitosis is diverged and transmitted to child cells, ensuring the continuity of hereditary information from each type of organisms.

Karioplasm - The liquid phase of the nucleus, in which the products of nuclear structures are dissolved in the dissolved form.

Nadryshko - Outlook, the most dense part of the nucleus.

The nucleoline includes complex proteins and RNAs, free or related potassium phosphates, magnesium, calcium, iron, zinc, as well as ribosomes. Eashes disappears before the start of cell division and is again formed in the last phase of the division.

Thus, the cell has a fine and very complex organization. The extensive network of cytoplasmic membranes and the membrane principle of the structure of organoids allow you to distinguish between the many chemical reactions in the cell. Each of the intracellular formations has its own structure and a specific function, but only when they are interacting, harmonious vital activity of the cell is possible. It is based on this interaction of the substance from the environment to the cell, and the exhaust products are derived from it into the external environment - the metabolism is performed. The perfection of a structural organization of cells could occur only as a result of a long biological evolution, in the process of which the functions performed by it were gradually more complicated.
The simplest single-celled forms are a cell, and the body with all its life manifestations. In multicellular organisms, cells form homogeneous groups - tissues. In turn, the tissues form organs, systems, and their functions are determined by the overall vital activity of a holistic organism.

2. Prokaryotic cell.

Procarniotes include bacteria and blue-green algae (cyania). The hereditary apparatus of prokaryotes is represented by one DNA annular molecule that does not form connections with proteins and containing each gene containing each gene - haploid organisms. In the cytoplasm there is a large number of small ribosomes; There are no or weakly expressed internal membranes. Plastic exchanging enzymes are diffuse. The Golgi apparatus is represented by separate bubbles. Enzyme systems of energy exchange are ordered on the inner surface of the outer cytoplasmic membrane. Outside the cell is surrounded by a thick cell wall. Many prokaryotes are capable of disputes in adverse conditions of existence; This distinguishes a small section of the cytoplasm containing DNA, and is surrounded by a thick multi-layer capsule. Metabolism processes inside the dispute are practically stopped. Finding into favorable conditions, the dispute is transformed into an active cellular form. The propagation of prokaryotes occurs simply division.

The average magnitude of prokaryotic cells is 5 microns. They do not have any internal membranes, except for the plasma membrane pensions. There are no layers. Instead of the cell kernel there is its equivalent (nucleoid), deprived of the shell and consisting of a single DNA molecule. In addition, bacteria may contain DNA in the form of tiny plasmids similar to extra-nuclear DNA eukaryotes.
In prokaryotic cells capable of photosynthesis (blue-green algae, green and purple bacteria) there are various structured large piercing membranes - thylacoids, according to its function, appropriate eukaryotic plasts. These same thylacoids or - in colorless cells - smaller pensions of the membrane (and sometimes the plasma membrane itself) is replaced by mitochondria in functionality. Others, difficult to differentiated pensions of the membrane are called mezas; Their function is not clear.
Only some organhelles of the prokaryotic cell are homologous to the corresponding eukaryota organelles. For prokaryotes, the presence of a mereine bag is a mechanically durable cell wall element

Comparative characteristics of plant cells, animals, bacteria, mushrooms

When comparing bacteria with eukaryotes, one can distinguish the only similarity - the presence of a cell wall, but similarities and differences in eukaryotic organisms deserve more attention. A comparison with components that are peculiar to both plants and animals, and mushrooms should be started. This is the kernel, mitochondria, the device (complex) of the Golgi, the endoplasmic reticulum (or the endoplasmic network) and the lysosomes. They are characteristic of all organisms, have a similar structure and perform the same functions. Now you should focus on differences. The vegetable cell, in contrast to the animal, has a cellular wall consisting of cellulose. In addition, the essential organelles characteristic of vegetable cells - plasts and vacuoles. The presence of these components is due to the need for plants to maintain a form, in the absence of a skeleton. There are differences and in the peculiarities of growth. In plants, it occurs mainly due to an increase in the size of vacuoles and stretching cells, while animals there is an increase in the volume of cytoplasm, and there is no vacuol at all. Plasts (chloroplasts, leukoplasts, chromoplasts) are characteristic mainly for plants, since their main task is to provide an autotrophic power method. In animals, in counterweights, there are digestive vacuoles that provide a heterotrophic power method. Mushrooms occupy a special position and for their cells are characterized by signs characteristic and for plants, and for animals. Like animal mushrooms inherent heterotrophic power supply, containing chitin cell shell, and the main basic substance is glycogen. At the same time, for them, as for plants, unlimited growth is characteristic, inability to move and power by suction.

All organisms having a cellular structure are divided into two groups: presense (procarniot) I. nuclear (eukaryota).

Procarniot - organisms that do not have a decorated cell core. The genetic material in the form of an annular circuit of DNA lies freely in the nucleoid and does not form real chromosomes. Typical sexual process. TO Prokaryotam Believe bacteria, incl. Cyanobacteria (blue-green algae). In the system of the organic world, prokaryotes are talent.

Eukaryota - organisms with decorated cellular core degraded from cytoplasm with nuclear shell. Genetic material is concluded in chromosomes. Eukarot cells have mitochondria, plasts, etc. Organo. For eukaryota is characterized by a sexual process.

Cells prokaryot have a relatively simple structure. N. it is organized kernel, it contains only one chromosome, which is not separated from the rest of the membrane cell, and lies directly in the cytoplasm. but all hereditary information is also recorded in it. Bacterial cell.

Cytoplasmprokaryot Compared to cytoplasm eukaryotic cells most importantly poorer in the composition of the structures. There there are numerous smallerthan in eukaryotes, ribosomes. The functional role of mitochondria and chloroplasts in prokaryotic cells are performed special, quite just organized membrane folds.

Cellsprokaryot , just likeeukaryotic Cells covered with plasma membrane, on top of which there is a cell shell or mucous capsule. Despite the relative simplicity, prokaryotes are typical independent cells.

In the structure of various eukaryotic Cells are similar. But along with similarities between the cells of the organisms of various kingdoms of wildlife, there are noticeable differences. They relate to both structural and biochemical features.

36. Home directions and driving forces of evolution.

Hereditary variability

Mutations and combinations create genetic inhomogeneity of the population, supply material for natural selection. The stronger the mutation process goes, the greater the effectiveness of natural selection.

Random (non-directional) Saving signs

Population waves - Periodic vibrations of the population number. For example: the number of hares is inconvenient, every 4 years there are very many of them, then a decline in the number. Value: During the decline, the gene drift occurs.

Genov drift: If the population is very small, the signs are saved or disappeared regardless of their utility, by chance.

Fight for existence -this is a combination of the relationship between the body with other organisms and with the environment, due to the fact that the organisms are born much more than they can survive, so they all lack food and territory. The struggle is divided into 3 types:

intraspecific (between individuals of one species),

interspecific (between individual species),

with environmental conditions.

Natural selection -This is the main, leading, guiding factor of evolution leads to adaptability, to the emergence of new species.

Insulation

Gradual accumulation of differences Between each other, populations can lead to the fact that they will turn into two different types, i.e. There will be a speciation.

Types of insulation / speciation:

Geographical - if there is an insurmountable bargain between populations - mountain, river or very long distance. For example, the larch of Siberian (in Siberia) and the larch Dauria (in the Far East).

Environmental (biological) - if two populations live on one territory, but can not cross. For example, different populations of trouts live in Lake Sevan, but spawningly go to different rivers flowing into this lake.

1. Introduction3
2. Procarniot3.
3. Eukariota4
4. Conclusion7.

List of references8

Introduction

The currently existing organisms are divided into two large groups - prokaryotes and eukaryotes.

Procarniotes include bacteria (eubacteria and archaebacteria) and to eukaryotes - mushrooms, plants and animals, most of which are multicellular organisms and only some are unicellular. Multicolve eukaryotes are constructed from varied cell functions, and these cells are significantly larger than pricing cells (the ratio of volumes of approximately 2000: 1). The most important distinctive feature of eukaryotic cells is the presence of the nucleus (Greek. Karion; hence the name "eukaryota") and other organelles.

Bacteria [from Greek. Bakterion, reduce. From Baktron, cane, staff] - representatives of the realm of Procariotae, including bacteria and blue-green algae. Bacteria are larger than viruses, most of them can be studied by light-optic microscopy. The prokaryotic cell is less than eukaryotic, the DNA is not surrounded by a nuclear membrane, and organelles of the mitochondria and chloroplasts are absent.

The cells of bacteria are surrounded by a particularly organized cell wall, have a limited number of departments (compartments) or are generally devoid of them. They also have differences in the synthesis of DNA, proteins and cell wall products. All known bacteria are divided into archaebacteria (that is, ancient bacteria) and eubacteria (to which most of the modern species belong).

Procarniot

Prokaryota (lat. Procaryota, from Lat. Pro - "Before", "To" and Greek. Άάρυον - "core"), or militant - unicellular living organisms that do not possess (in contrast to eukaryotes) decorated cell core.

For prokaryotic cells, the absence of a nuclear shell is characterized, DNA is packed without the participation of histones.

The genetic material of prokaryotes is represented by one DNA molecule, closed in the ring, there is only one replicon. There are no organides with a membrane structure in cells. Characteristics:

The presence of the decorated kernel - no
The presence of flagella, plasmid and gas vacuoles
Structures in which photosynthesis - chlorosomes
The form of reproduction is an intact method, there is a pseudo-sexual process, as a result of which only the exchange of genetic information occurs, without increasing the number of cells. This section is not completed.

The main genetic material of prokaryotic (from Greek. Pro - BE and Caryon - the core) is in the cytoplasm in the form of a ring molecule DNA. This molecule (nucleoid) is not surrounded by a nuclear sheath characteristic of eukaryotes, and is attached to the plasma membrane (Fig. 1). Thus, prokaryotes do not have a decorated kernel. In addition to the nucleoid in the prokaryotic cell, a small annular DNA molecule is often found, called plasmid. Plasmids can move from one cell to another and integrated into the main DNA molecule.

Some prokaryotes have a plasma membrane growing: mesosomes, lamellar tylakoids, chromatophores. They are concentrated enzymes involved in photosynthesis and in respiratory processes. In addition, the mesosomes are associated with DNA synthesis and protein secretion.

Prank cells have small dimensions, their diameter is 0.3-5 μm. From the outdoor side of the plasma membrane of all prokaryotes (with the exception of mycoplasmas) there is a cell wall. It consists of complexes of proteins and oligosaccharides, laid by layers, protects the cell and supports its shape. From the plasma membrane, it is separated by a small intermambrane space.

In the cytoplasm of prokaryotes, only non-emblems of ribosomes are found. According to the ribosome structure, prokaryotes and eukaryotes are similar, but the ribosomes of prokaryotes have smaller dimensions and are not attached to the membrane, and are located directly in the cytoplasm.

Many prokaryotes are moving and can swim or slide with flavors.

Procarnibot usually multiplies by dividing the sun (binary). The division is preceded by a very short stage of doubling, or replication, chromosomes. So prokaryotes are haploid organisms.

Procarniotes include bacteria and cinema algae, or cyanobacteria. Prokaryotes appeared on Earth about 3.5 billion years ago and were probably the first cell form of life, giving rise to modern prokaryotam and eukaryotas.

Eukaryota

Eukaroto, or nuclear (lat. Eucaryota from Greek. Ύύ- - well and κάρυον - core) - the talent of living organisms whose cells contain kernels. All organisms, except bacteria and archaeys, are nuclear.

Animals, plants, mushrooms, as well as groups of organisms under the general name of the protists - are all eukaryotic organisms. They can be unicellular and multicellular, but everyone has a common cell structure. It is believed that all of these so increasing organisms have a general origin, so the nuclear group is considered as the monophiletic taxon of the highest rank. According to the most common hypotheses, eukaryotes appeared 1.5-2 billion years ago. An important role in the evolution of eukaryota was played by symbogenesis - symbiosis between the eukaryotic cell, apparently, already had a core and capable of phagocytosis, and the bacteria varied by this cell - precursors of mitochondria and chloroplasts.

Eukaryotic cells on average are much larger than prokaryotic, the difference in the volume reaches thousands of times. Eukarot cells include about a dozen species of various structures known as organoids (or organelles, which, however, somewhat distorts the initial meaning of this term), of which many are separated from cytoplasm with one or more membranes. In prokaryotic cells there is always a cell membrane, ribosomes (substantially different from eukaryotic ribosomes) and genetic material - bacterial chromosome, or gene, but internal organides surrounded by membrane are rarely found. The kernel is a part of the cell, surrounded in the eukaryota by a double membrane (two elementary membranes) and containing genetic material: DNA molecules, "packed" in chromosome. The kernel is usually one, but there are multi-core cells.

There are several options for fissioning eukaryota in the kingdom. The first were allocated by the kingdoms of plants and animals. Then the kingdom of mushrooms was allocated, which, due to biochemical features, according to most biologists, cannot be counted for any of these kingdoms. Also, some authors allocate the kingdoms of simplest, mixomycetes, chromists. Some systems have up to 20 kingdoms. According to the system of Thomas Cavalier-Smith, all eukaryotes are divided into two monophyletic taxes - Uniconts and biscontases.

The most important, fundamental feature of eukaryotic cells is associated with the location of the genetic apparatus in the cell. The genetic apparatus of all eukaryotes is in the kernel and is protected by a nuclear shell (in Greek "eukaryota" means having a kernel). DNA eukaryota linear (DNA DNA ring and is located in a special area of \u200b\u200ba nucleoid cell, which is not separated by the membrane from the rest of the cytoplasm). It is associated with proteins-histones and other proteins chromosomes, which are not in bacteria.

In the life cycle, eukaryotes are usually present two nuclear phases (haplophaz and diplophase). The first phase is characterized by a haploid (single) set of chromosomes, further, merging, two haploid cells (or two cores) form a diploid cell (core) comprising a double (diploid) chromosome set. Sometimes in the next division, and more often a few divisions of the cell again becomes a haploid. Such a life cycle and in general, diploidity for prokaryotic is not characteristic.

The third, perhaps, the most interesting difference is the presence of special organelles in eukaryotic cells, which have its own genetic apparatus that breed division and surrounded by membrane. These organelles are mitochondria and plasts. In terms of its structure and life, they are strikingly similar to bacteria. This circumstance pushed modern scientists to the idea that such organisms are descendants of bacteria that have entered into symbiotic relations with eukaryotes. Prokaryotes are characterized by a small amount of organelle, and none of them is surrounded by a double membrane. There are no endoplasmic reticulum, the Golgi, Lizosoma, no endoplasmic reticulum.

Another important distinction between prokaryotes and eukaryotes is the presence of endocytosis in eukaryotes, including many groups of phagocytosis. Phagocytosis (literally "eating a cell") call the ability of eukaryotic cells to capture, entering into a membrane bubble, and digest a variety of solid particles. This process provides an important protective function in the body. For the first time he was opened by I.I. Mechnikov from marine stars. The emergence of phagocytosis in eukaryotes is most likely due to the average size (hereinafter referred to as the dimensional differences is written in more detail). The dimensions of prokaryotic cells are incommensurable, and therefore in the process of evolutionary development of eukaryota they had a problem of supplying the body with a large amount of food. As a result, the first real, moving predators appear among eukaryotes.

Most bacteria has a cell wall other than eukaryotic (not all eukaryotes have it). In prokaryotes, it is a solid structure consisting mainly of Mainin (at the Archey from Pseudo-Marein). The structure of Murein is such that each cell is surrounded by a special mesh bag, which is one huge molecule. Among the eukaryotes, many rubbers, mushrooms and plants have a cell wall. In mushrooms, it consists of chitin and glucans, in lower plants - from cellulose and glycoproteins, diatoms of algae synthesized the cell wall of silicon acids, in higher plants it consists of cellulose, hemicellulose and pectin. Apparently, for larger eukaryotic cells, it was impossible to create a cell wall from one molecule high by strength. This circumstance could force eukaryotes to use other material for the cell wall. Another explanation is that the overall ancestor of eukaryotes in connection with the transition to predatoryness has lost the cell wall, and then the genes responsible for the synthesis of Minein.

When returning part of eukaryotes to the inspection power, the cell wall appeared again, but already on another biochemical basis.

Diverse and metabolism in bacteria. In general, there are four types of food, and everything is found among bacteria. These are photoeautrophic, photogometrophopic, chemoavtrophithotrophic, chemoometerotrophic (phototrophic use solar energy, chemotrophic use chemical energy). Eukaryotes either themselves synthesize energy from sunlight, or use the finished energy of such origin. This may be due to the appearance among the eukaryot predators, the need to synthesize the energy for which it disappeared.

Another difference is the structure of flavors. Bacteria are thin - only 15-20 nm in diameter. This is hollow threads from flag relax. The structure of eukaryot flagella is much more difficult. They represent the grown cells surrounded by the membrane, and contain cytoskeleton (axonom) of nine pairs of peripheral microtubules and two microtubes in the center. Unlike rotating prokaryotic flavors, eukaryotic flagella flashes or argue. Two groups of organisms under consideration, as already mentioned, differ greatly and in their average sizes. The diameter of the prokaryotic cell is usually 0.5-10 μm, when the same indicator in eukaryotes is 10-100 μm. The volume of such a cell is 1000-10000 times greater than prokaryotic. Prokaryott ribosomes are small (70s-type). The eukaryota ribosomes are larger (80s-type).

Apparently, the time of these groups is also different. The first prokaryotes arose in the process of evolution about 3.5 billion years ago, about 1.2 billion years ago eukaryotic organisms occurred.

Conclusion

Eukariotes call cells with a core formed, and prokaryotami - with not formed. Procarniotes include bacteria (archaebacteria and cyanobacteria), combined by a common term "fifty". The cage of ordinary shotgun is covered with cellulose shell. Drobyanki occupy a certain place in the cycle of substances in nature:

Cyanobacteria - organic substances synthesize;

Bacteria - Mineralize organic matter.

Many bacteria play an important role in medicine and veterinary medicine as causative agents of infections.

Prokaryotic cells, which include bacteria, in contrast to eukaryotes, have a relatively simple structure. In prokaryotic cell there is no organized kernel, it contains only one chromosome, which is not separated from the rest of the membrane cell, and lies directly in the cytoplasm.

However, all the hereditary information of the bacterial cell is also recorded.

The cytoplasm of prokaryotes compared with the cytoplasm of eukaryotic cells is much poorer in the composition of the structures. There are numerous smaller than in eukaryotes, ribosomes. The functional role of mitochondria and chloroplasts in prokaryotic cells are performed by special, quite simply organized membrane folds.

Procarniot cells, as well as eukaryotic cells, coated with a plasma membrane, on top of which the cell envelope or mucosa is located.

Despite the relative simplicity, prokaryotes are typical independent cells.

Bibliography

1. Bilic G. L., Kryzhanovsky V. A. Universal Atlas. Biology. In 3 books. Book 2. Viruses. Procarniot. Plants. Mushrooms. Mucus. Animals (comparative anatomy). - Onyx 21st century, Harvest, 2005, 1136 pp.
2. Zharikova G.G. Microbiology of food products. Sanitation and hygiene 2nd ed., Ched. 2007 304 p.
3. Modern microbiology. Prokaryotes (set of 2 books) / Edited by J. Lengeler, the city of the grace, Schlegel. - World, 2009, 1152 pp.

All living organisms are divided into subsidiary and cellular. Villagers include viruses and phages. The second group, cellular, is divided into prokaryotes and eukaryotes, which are predominant and nuclear organisms.

Procarniot

The first cellular, prokaryotes, arose on Earth more than 3 billion years ago. It was the greatest jump in the development of life. Prokaryotes are bacteria. They have a relatively simple structure. Hereditary information, DNA, is in their primitive, containing little protein of the ring-shaped chromosome. It is located in a special area of \u200b\u200bcytoplasm, a nucleoid, not separated from the rest of the membrane cell. Basic than distinguished prokaryotes and eukaryotes from each other, this is what the present core is absent in the cells of the first type.

The cytoplasm of predominant cells has much less cellular structures. Of these are ribosomes, smaller compared to ribosomes of eukaryoid cells. The role of mitochondria in prokaryotes belongs to simple membrane structures. None in them and chloroplast. Prokaryotes have a plasma membrane, over which the cell shell is located. They differ from eukaryt significantly smaller sizes. In some cases, the treasonids can be so-called plasmids - small, in the form of a ring,

Eukaryota

All nuclear cells are distinguished by a common plan of structure and general origin. They arose from the presenter cells of 1.2 billion years ago. Their structure is much more complicated. And prokaryotes, and eukaryotes have a cell membrane. But otherwise their structural and biochemical features are largely different. The most important difference is that in nuclear cells there is a true core in which their genetic information is stored.

The kernel is degraded from the cytoplasm of a special membrane consisting of an external and internal layers. It is similar to the plasma membrane, but contains pores. Thanks to them, the exchange between the cytoplasm and the core is carried out. The cell genome consists of a whole set of chromosomes, these prokaryotes and eukaryotes are also different from each other. DNA in eukaryot chromosomes is related to histonet proteins.

In there are nuclei, in which ribosomes are formed. Structural mass, karyoplasm, surrounds chromosomes and nuclei. Each type of animals and plants is characteristic of its own, strictly defined chromosome set. When dividing the cells, they double and then distributed across the daughter cells

If we consider prokaryotes and eukaryotes, the differences are visible in the cytoplasm of cells.

For plant cells, the presence of a large central vacuole and plastic. Can move the kernel to the periphery of the cell. Nutrient reserve carbohydrate vegetable cell - starch. Outside, plant cells are covered with cellulose. In the cell center there is no centriol, which can be seen only in algae.

Animal cells do not have a central vacuole, a plastic and a dense cell shell. There are central cells in the center of the cell. Reserve carbohydrate in animal cells - glycogen.

The mushroom cells are not always the mushrooms. The wall of the cell consists of chitin, there is no plast form in the cytoplasm, but in the center of the cell central vacuole is available. The reserve of carbohydrates is also glycogen.

In the cytoplasm eukaryota there are mitochondria, lysosomes, an endoplasmic network, movement organoids. Ribosomes are significantly larger than Ribosomes prokaryotes. Cell cytoplasm is divided into separate compartments, compartments, with special shells consisting of lipids. Each of them proceeds their biochemical processes. This is almost not found in prokaryot.

In general, prokaryotes and eukaryotes express the laws of evolution, which is characterized by movement from simpler forms to more complex.

However, the predominant cells are characterized by a large plasticity and variety of metabolic processes. Many bacteria can receive energy due to light or chemical reactions, exist in an exemplary environment (anaerobic bacteria). Thanks to this, they fit into the picture of the modern world.