All live matter consists of cages. These elementary live systems, the smallest structurally functional units of a body, carry out all basic processes of its life-support.
Imagine that you have a rest at sea coast. Take in a hand a sand handful. How many there grains of sand? Hundreds, thousand? Perhaps, them not to count. And how many grains of sand would be in the figure of the person made of sand? It is difficult even to present.
As well as the sand figure, a body of the person consists of tiny bricks - cages. They much less grains of sand: to see them it is possible only under a microscope. Cages of our body are not similar against each other in size, colour and the form. At the majority of them under a thin cover the transparent substance similar to jelly, and in it - still smaller internal structures, so-called contains. organoidy. The size, the cage form, and also types available in it organoidov depend on the functions which are carried out by it in an organism for its maintenance accurate and trouble-free work.
Of cages consist not only people, but also all animals, plants and other live organisms. Actually, the cage is the least structurally functional unit of a live matter. Some elementary animals consist all of one cage, for example, an amoeba. In a small larva - some thousand cages, in the insect who has grown from it - some millions, and in the person - are terrible to think! - more than 50 000 000 000 000 (i.e. Millions millions) cages.
That it for bricks?
The Usual animal cage (plants of a cage have some others) is surrounded by a thin membrane from plasma and contains zheleobraznuju cytoplasm with ten various organoidov. The cage of the person is better for considering on an example of a cage of a liver.
Each cage of a liver (so-called. gepatotsit) has width from 10 to 20 microns (1 micron - the one 100-th millimetre) and contains all cores organoidy. Gepatotsit is responsible for the difficult chemical reactions connected with digestion of food and mastering of nutrients.
The Red blood cell has other structure and in general is deprived organoidov. Its name - eritrotsit (names of many cages come to an end on "-чш=" and the science about cages is called as cytology), the form it reminds a doughnut, the size - only 2 microns, and a problem - to transfer oxygen from lungs to fabrics.
Updating of cages
In our body there are tens various kinds of cages. Similar to spiders osteotsity form our bones, cartilages in joints consist from hondrotsitov, and muscular cages incorporate in huge chains to 30 sm at length at a thickness in hair. Lungs, a cardiac muscle, a brain and nerves also are made of different types of cages.
During all life at the person the identical set of types of cages, but not cages remains. Cages of the majority of types have the limited term of a life. A white blood cell (leukocyte), struggling with an infection, some hours, and an integument cage - will live month all.
Eritrotsit on the average lives till 4 months, then grows old, changes the form and perishes, and its remains are processed by a liver and a spleen. On change to it comes new eritrotsit, and every second them in an organism it is developed to 2 million! And here the age of nervous cages corresponds to age of the person - they, as it is known, are not restored.
a cage Cover
The Thin cover of a cage is called as a cellular or plasmatic membrane. Its width - 0,1 microns (i.e. One ten-thousand millimetre). Elasticity of a membrane allows a cage to change the form.
The Membrane passes in a cage only the substances necessary to it: oxygen for breath, nutrients for internal processes of processing and energy sources - usually in the form of glucose, i.e. Sugar. At the same time, through a membrane harmful chemical substances are deduced from a cage (for example, carbonic gas) and an other waste of ability to live.
Molecules of one substances in itself move from places where it is too much them, there, where they do not suffice. For other molecules in a membrane there are "pumps" and "doors". Process vsasyvanija and pushing out of molecules through a membrane is called as active transport.
In a usual light microscope the membrane is visible only as a thin dark line round a cage, but under the electronic microscope, allowing to observe objects, in thousand times smaller on the size, it is possible to consider the mosaic structure of a membrane consisting of a double number fosfolipidnyh of molecules (zhiropodobnoe substance), stuck round by fiber islets. In these islets there is a majority of "pumps" and "doors". At some cages the plasmatic membrane not tense and smooth, and forms folds or is supplied by hairs similar to fingers - microfibers. Folds and hairs increase the area of a surface of a cage and help it to absorb better nutrients and to get rid of unnecessary products. For example, the intestinal path of the person vystlan cages with very long fibers that in the course of digestion to soak up is as much as possible nutrients. On separate sites of a surface of a cage the membrane forms the folds wrapped in depth of a cage - so-called. endoplazmaticheskuju a network.
the Most complicated structure
In a cellular membrane the transparent cytoplasm filling space between organoidami is concluded. Through a weak microscope it looks as shapeless jelly, and in a modern microscope it is well visible that cytoplasm in all directions is crossed by the smallest constantly changing a configuration palochkovidnye and threadlike structures. They serve a cage as a skeleton, forming it, keeping organoidy in a certain place and forming channels on which cage contents move
Microscopic tubular and nitevye formations also are important for cage movement: they accumulate, are sharply reduced, quickly reconstructed, and thus some cages (in particular, white blood) move, like amoebas.
One of the major organoidov cages is called mitohondriej. Outwardly mitohondrija reminds sausage, and inside forms folds. For the majority of cages is available at least on neskolku mitohondry. They - its power units.
the Transmission of energy
In any power unit one form of energy will be transformed to another; we will tell, on power station burnt coal, gas or energy of the sun turn to electricity so useful to us. Almost as operates mitohondrija. It incorporates different quantities of glucose and other Sugars, separate fats and the other substances rich with energy getting to a cage in the course of digestion of food eaten by the person, and then on a surface of internal folds acid (ATF), serving in a cage a universal carrier of energy transforms them into connection molecules under the name adenozintrifosfornaja. The cage accumulates these molecules and constantly uses them in the course of ability to live.
Any cage consumes quantity ATF for maintenance of a life and normal, healthy functioning. If the cage makes any substances "for export", splits a harmful waste or changes the form, additional energy is necessary for it. The more energy the cage consumes, the it is more mitohondry contains. For example, in a muscular cage which often changes the form during muscle reduction, there can be some honeycombs mitohondry, every second power molecules processing millions.
One of the major groups of molecules of live organisms is made by fibers (protejpy). Some fibers form structural making cages - for example, islets mentioned above on its membrane. Other fibers form rather important cellular substances named enzymes or enzimami. Enzymes appear in hundreds various kinds, have the special form and operate speed of course of the chemical reactions occurring in a cage. The cage in necessary quantity develops the necessary enzymes, and those operate its internal processes. Thus, fibers form a cage and at the same time are its instruments of labour.
Fibers are developed in the round ribosomes which are in cytoplasm. Sometimes they are grouped in the polyribosomes randomly scattered in cytoplasm, but is more often one by one settle down on folds endoplazmaticheskoj grids.
Fibers consist of nearby 20 kinds of more simple molecules of amino acids. Ribosomes, burning ATF, choose amino acids from cytoplasm, connect them in the necessary sequence and in the necessary proportions, forming various fibers.
The Endoplazmatichesky network happens two kinds: rough granuljarnaja to which membranes the set of ribosomes, and smooth agranuljarnaja is attached. On agranuljarnoj networks of ribosomes are not present and as believe, it is involved in development of other important molecules - lipidov (similar themes that together with fibers form mosaic structure of a cellular membrane).
Some fibers and lipidy are used by a cage for internal processes, and others go "for export". For example, separate cages of a stomach, an intestines and a pancreas develop digestive albuminous enzymes which enter reaction with the eaten food and split it on suitable particles for mastering.
As a matter of fact, each cage developing fiber for other parts of an organism, includes set granuljarnyh endoplazmaticheskih networks, and the cage developing great volumes lipidov or their derivatives (for example, natural hormones of steroids), has more than smooth networks.
Some fibers as in convolutions, are wrapped in covers and are called vakuoljami. These vials can collect and remain near to the cage center in organoide, Goldzhi called as a complex by name opened it in 1898 of the Italian scientist.
If fiber is necessary to a cage for internal processes, the vial moves on cytoplasm to destination and there opens, or merges with other cover, and lets out the contents. If it is necessary for fiber to leave a cage, the vial approaches to an external membrane of a cage and merges with it. Fibers arrive in blood or other environments of an organism and dvizhutsja further to the terminal point.
Importance of a membrane for a cage life is proved by work of two more organoidov - lizosom and peroksisom.
Some enzymes split fibers in the course of digestion or at replacement of the collapsed cages. These moshch nye enzymes soon after formation keep within in lipidno-membrannye "packages" - lizosomy, interfering their contact with cellular fibers in surrounding cytoplasm that they did not undertake to digest contents of the cage.
On the one hand, lizosoma helps to regulate consumption of substances: at rupture of its membrane enzymes are liberated and split the particles which have got to a cage of food or microorganisms. With another, lizosomy constrain receipt of digestive enzymes in a stomach and an intestines: they reserve enzymes and if necessary let out them from cages.
Peroksisomy are responsible detoksikatsiju for cages: they neutralise poisons and other dangerous substances, pronikshie in a cage. Accumulation of alcohol and other toxins would have a pernicious effect on an organism, and peroksisomy care of cleanliness and "sobriety" of cages.
Resnichki and zhgutiki
One more cellular organoid is called tsentriolju. Usually two adjacent to each other tsentrioli are in the center of a cage and at its division disperse to poles, defining so-called. An axis of a spindle of division. TSentriol looks as the hollow cylinder of the small height which wall consists of 9 groups of longitudinal tubules, on three tubules in each group.
Tsentrioli are capable to self-reproduction; their exact copies rise to a surface of a cage and there form a basis for cellular ledges - resnichek and zhgutikov.
On the guard of lungs
The Cages covering internal walls of lungs, are supplied by tens resnichek which continually "blink", releasing lungs from harmful particles and preserving their gentle fabric against pollution.
Zhgutiki is much longer resnichek. ZHgutikami, for example, are supplied spermatozoidy which are outwardly similar to tadpoles with long tails. Thanking zhgutiku spermatozoid it is capable to move in the liquid environment.
In the majority of cages the basic and the most important organoidom is the kernel. It is surrounded by a double cover, is supplied ache roundish and slot-hole apertures.
The kernel Cover is connected with a membrane mi endoplazmaticheskoj networks and to an external membrane of a cage. In a kernel is one or several dark kernels where parts of ribosomes are formed.
It is possible to name the Kernel control center of a cage safely. The kernel "prompts" organoidam and another I make shchim cages that they should do and during what moment. The kernel also dispatches "the instructions", what fibers, lipidy and other vital molecules should be developed. It defines the form, size, activity and term of existence of a cage. The kernel possesses such large powers (and such big possibilities) because contains chromosomes, and in them genes - "a life code", instructions for the major process on the Earth - a continuation of the family.