known that most living things are made up of water in the form of free or bound at 70 percent or more.Whence it is taken as where it localized?It turns out that every cell in its structure has up to 80% of water and only the remainder being the weight of dry matter.
And the main "water" structure is just the cytoplasm of the cell.This is a complex, heterogeneous, dynamic internal environment, with structural features and performs functions that we met on.
protoplasts
This term to denote all the interior contents of any eukaryotic minute structure, separated from the plasma membrane of its other "colleagues".That is, here enters the cytoplasm - the internal environment of the cell organelles, it located nucleus with nucleoli, and genetic material.
What organelles are located within the cytoplasm?It:
- ribosome;
- mitochondria;
- EPS;
- Golgi apparatus;
- lysosomes;
- cell activation;
- vacuoles (plants and fungi);
- cell center;
- plastids (in plants);
- cilia and flagella;
- microfilaments;
- microtubules.
kernel separated karyotheca with nucleoli and DNA molecules, also contains the cytoplasm of the cell.In the center it in animals, closer to the wall - in plants.
Thus, the structural features of the cytoplasm will largely depend on the type of cell from the organism it belongs to the realm of living things.In general, it takes all the available space inside and a number of important functions.
Matrix or hyaloplasm
structure of the cell cytoplasm is composed primarily of its division into parts:
- hyaloplasm - the liquid part of the constant;
- organelles;
- inclusion - variable structure.
Matrix or hyaloplasm - is the main component of the interior, which can be in two states - ash and gel.
Cytosol - such cytoplasm of the cell, which has a liquid aggregate character.Tsitogel - the same thing, but in a more dense, rich large organic molecules, condition.The total chemical composition and physical properties hyaloplasm expressed as:
- colorless, viscous colloidal material sufficiently thick and slimy;
- has a clear differentiation of the structural organization, but as a result of mobility can easily change it;
- presented inside the cytoskeleton or microtrabecular lattice that is formed by protein filaments (microfilaments and microtubules);
- on parts of the lattice and are located all the structural parts of the cell as a whole and by microtubules, Golgi apparatus, and EPS between hyaloplasm going through a message.
Thus hyaloplasm - important part, which provides many functions in the cell cytoplasm.
composition cytoplasm
If we talk about chemical composition, then the share of water in the cytoplasm accounts for about 70%.This average value, as in some plants have cells in which up to 90-95% water.The dry substance is:
- proteins;
- carbohydrates;
- phospholipids;
- cholesterol and other nitrogen-containing organic compounds;
- electrolytes (mineral salts);
- inclusions in the form of droplets of glycogen (in animals cells) and other substances.
General chemical reaction of the environment - alkaline or slightly alkaline.If we consider how the cytoplasm is the cell, it should be noted this feature.Some gathered at the edge, in the region of the plasma membrane, called ectoplasm.The other part is oriented towards the karyotheca bears the name endoplasm.
structure of the cell cytoplasm is determined by special structures - microtubules and microfilaments, so they take a closer look.
Microtubules
Hollow small elongated particles of up to several micrometers.Diameter - from 6 to 25 nm.Because of too scanty indicators full and succinct study of these structures is not yet possible, however, suggest that their walls are composed of the protein tubulin agents.This compound has a helically twisted stranded molecule.
Some functions in the cell cytoplasm was performed due to the presence of microtubules.For example, they participate in forming the cell walls of fungi and plants, some bacteria.In animal cells, they are much smaller.Also, these structures perform the movement of organelles in the cytoplasm.
Themselves microtubules are unstable, can quickly disintegrate and re-emerge from time to time is updated.
microfilaments
sufficiently important elements of the cytoplasm.Are long filaments of actin (globular protein), which are intertwined with each other, form a common network - cytoskeleton.Another name - microtrabecular grille.This kind of structural features of the cytoplasm.After all, thanks to this cytoskeleton holds together all organelles, they can easily communicate with one another, they pass through matter and molecules is carried out metabolism.
known, however, that the cytoplasm - the internal environment of the cell, which is often able to change their physical data become more liquid or viscous, change the structure (the transition from sol to gel and vice versa).In this connection microfilaments - dynamic, labile moiety capable of quickly rebuilt, modified, disintegrate and re-form.
plasma membranes
important for the cells is the presence of well-developed and well-functioning of many membrane structures, which also is a kind of structural features of the cytoplasm.It is through the plasma membrane barrier transport of molecules occurs, nutrients and metabolic products, gas for the processes of respiration, and so on.That is why most of these organelles has a structure.
They, like the network, located in the cytoplasm and delimit an inner content of their hosts apart from the environment.Defend and protect against unwanted substances and bacteria that pose a threat.
structure is similar to most of them - liquid-mosaic model treats each as a biosloy plasmalemma lipids permeated different protein molecules.
Since the functions in the cell cytoplasm - is primarily a transport connection between all its parts, the presence of the majority of the membranes of organelles is one of the structural parts hyaloplasm.Integrated, all together, they perform the common tasks to ensure the life of the cell.
Ribosomes
small (20 nm) spherical structures consisting of two halves - subunits.These halves can exist together or disconnected at any time.The basis of the composition: rRNA (ribosomal ribonucleic acid) and proteins.The main localization of the ribosomes in the cell:
- nucleus and nucleoli, which are formed themselves subunit on the DNA molecule;
- cytoplasm - the ribosomes are finally formed into a single structure combining halves;
- nuclear membrane and endoplasmic reticulum - they ribosome synthesize protein and immediately sent him inside organelles;
- mitochondria and chloroplasts of plant cells themselves are synthesized within the body itself ribosomes and proteins are produced, that is, in this respect exist independently.
functions of these structures are in the synthesis and assembly of protein macromolecules that are spent on the life of the cell.
endoplasmic reticulum and Golgi apparatus
A large network of tubules, tubules and vesicles forming a conduction system located inside the cell and the entire volume of the cytoplasm, is known as the endoplasmic reticulum, or reticulum.Its function corresponds to the structure - organelles ensure the relationship between themselves and the transport of nutrient molecules to organelles.
Golgi complex, or a unit, performs the function of essential substances (carbohydrates, fats, proteins) in the special cavities.They are limited by cytoplasmic membranes.Also, it is the organelle is the site of synthesis of fats and carbohydrates.
Peroxyoms
and lysosomes Lysosomes - small rounded structures that resemble blisters filled with fluid.They are numerous and are distributed in the cytoplasm, which are freely movable within the cell.The main task of them - the dissolution of foreign particles, that is, the elimination of "enemies" in the form of dead portions of cellular structures, bacteria and other molecules.
liquid contents of the enzyme saturation, so lysosomes participate in the degradation of macromolecules to their monomeric units.
Peroxyoms - small oval or round organelles with a single membrane.Filled with liquid contents, comprising a large number of different enzymes.They are among the main consumers of oxygen.Its function is performed depending on the type of cell in which they reside.Possible for the synthesis of myelin sheath of nerve fibers, and may also perform oxidation and neutralization of toxic substances and different molecules.
Mitochondria
These structures did not for nothing called the power (power) stations in the cell.It is in them is formed the main energy - molecules of adenosine triphosphate, or ATP.In appearance resemble bean.The membrane bounding the mitochondria from the cytoplasm, double.The internal structure of highly folded to increase the surface of the ATP synthesis.The folds are called cristae, contain large amounts of different enzymes to catalyze the synthesis processes.
Most mitochondria are muscle cells in animals and humans, since they require high maintenance and energy consumption.
phenomenon cyclosis
movement in the cell cytoplasm is called cyclosis.It consists of several types:
- oscillating;
- rotary or circular;
- struychatoe.
Any movement necessary to provide a number of important functions of the cytoplasm: full move organelles inside hyaloplasm, uniform exchange of nutrients, gases, energy excretion of metabolites.
cyclosis occurs in both plant and animal cells, with no exceptions.If it continues, the body dies.Therefore, this process - it is also an indicator of life beings.
Thus, we can conclude that the cytoplasm of animal cells, plant, either eukaryotic - very dynamic, living structure.
difference between the cytoplasm of animal and plant cells
actually a little different.The general plan of the structure, functions performed completely similar.However, some differences still there.For example:
- cytoplasm of plant cells contain more microtubules, which are involved in the formation of their cell walls than microfilaments.Animals vice versa.
- The cellular inclusions in the cytoplasm of plants are corn starch, in animals as it drops glycogen.
- plant cell is characterized by the presence of organelles that are not available in animals.It plastids, the vacuole and the cell wall.
In other respects, the two structures are identical in composition and structure of the cytoplasm.Can vary the amount of certain elemental units, but their presence is necessary.Therefore, the value in the cell cytoplasm of both plants and animals are equally large.
role in the cell cytoplasm
value in the cell cytoplasm is great, not to say that it defines.It is the foundation, which houses all the vital structures, so hard to overestimate its role.You can formulate a few basic points that reveal the value.
- That it brings together all the components of the cells in a single integrated system, the ongoing process of life harmoniously and collectively.
- Thanks to a part of the water, the cytoplasm of the cell acts as a medium for the many complex interactions of biochemical and physiological reactions of substances (glycolysis, food, gas exchange).
- This is the main "container" for the existence of the cell organelles.
- By microfilaments and tubes forms the cytoskeleton, tying organelles and allowing them to move around.
- It is in the cytoplasm concentrated series of biological catalysts - enzymes, without which there is no biochemical reaction.
To summarize, it is necessary to say the following.Role in the cell cytoplasm virtually key because it - the basis of all the processes, the medium life and substrate reactions.
