The amount of water in different cells. The chemical composition of a plant cell. Learning new material

The water content in various plant organs varies within fairly wide limits. It varies depending on environmental conditions, age and type of plants. Thus, the water content in lettuce leaves is 93-95%, corn - 75-77%. The amount of water is not the same in different organs of plants: sunflower leaves contain 80-83% of water, stems - 87-89%, roots - 73-75%. The water content, equal to 6-11%, is typical mainly for air-dry seeds, in which vital processes are inhibited.

Water is contained in living cells, in the dead elements of the xylem and in the intercellular spaces. In the intercellular spaces, water is in a vapor state. Leaves are the main evaporating organs of a plant. In this regard, it is natural that the largest amount of water fills the intercellular spaces of the leaves. In a liquid state, water is found in various parts of the cell: the cell membrane, vacuoles, and protoplasm. Vacuoles are the most water-rich part of the cell, where its content reaches 98%. At the highest water content, the water content in the protoplasm is 95%. The lowest water content is characteristic of cell membranes. Quantitative determination of water content in cell membranes is difficult; apparently, it ranges from 30 to 50%.

The forms of water in different parts of the plant cell are also different. The vacuolar cell sap is dominated by water retained by relatively low molecular weight compounds (osmotically bound) and free water. In the shell of a plant cell, water is mainly bound by high-polymer compounds (cellulose, hemicellulose, pectin substances), i.e., colloidally bound water. In the cytoplasm itself there is free water, colloidally and osmotically bound. Water located at a distance of up to 1 nm from the surface of a protein molecule is firmly bound and does not have a regular hexagonal structure (colloidal-bound water). In addition, there is a certain amount of ions in the protoplasm, and, consequently, part of the water is osmotically bound.

The physiological significance of free and bound water is different. Most researchers believe that the intensity of physiological processes, including growth rates, depends primarily on the content of free water. There is a direct correlation between the content of bound water and the resistance of plants to adverse external conditions. These physiological correlations are not always observed.

A plant cell absorbs water according to the laws of osmosis. Osmosis is observed in the presence of two systems with different concentrations of substances, when they communicate with a semipermeable membrane. In this case, according to the laws of thermodynamics, the concentrations equalize due to the substance for which the membrane is permeable.

When considering two systems with different concentrations of osmotically active substances, it follows that the equalization of concentrations in systems 1 and 2 is possible only due to the movement of water. In system 1, the concentration of water is higher, so the flow of water is directed from system 1 to system 2. When equilibrium is reached, the real flow will be zero.

The plant cell can be considered as an osmotic system. The cell wall surrounding the cell has a certain elasticity and can be stretched. Water-soluble substances (sugars, organic acids, salts) that have osmotic activity accumulate in the vacuole. The tonoplast and plasmalemma perform the function of a semipermeable membrane in this system, since these structures are selectively permeable, and water passes through them much more easily than substances dissolved in cell sap and cytoplasm. In this regard, if the cell enters the environment, where the concentration of osmotically active substances will be less than the concentration inside the cell (or the cell is placed in water), water, according to the laws of osmosis, must enter the cell.

The ability of water molecules to move from one place to another is measured by the water potential (Ψw). According to the laws of thermodynamics, water always moves from an area with a higher water potential to an area with a lower potential.

Water potential(Ψ в) is an indicator of the thermodynamic state of water. Water molecules have kinetic energy, they move randomly in liquid and water vapor. The water potential is greater in the system where the concentration of molecules is higher and their total kinetic energy is greater. Pure (distilled) water has the maximum water potential. The water potential of such a system is conditionally taken as zero.

The units of water potential are units of pressure: atmospheres, pascals, bars:

1 Pa = 1 N/m 2 (N-newton); 1 bar=0.987 atm=10 5 Pa=100 kPa;

1 atm = 1.0132 bar; 1000 kPa = 1 MPa

When another substance is dissolved in water, the concentration of water decreases, the kinetic energy of water molecules decreases, and the water potential decreases. In all solutions, the water potential is lower than that of pure water, i.e. under standard conditions, it is expressed as a negative value. Quantitatively, this decrease is expressed by a quantity called osmotic potential(Ψ osm.). Osmotic potential is a measure of the reduction in water potential due to the presence of solutes. The more solute molecules in the solution, the lower the osmotic potential.

When water enters the cell, its size increases, the hydrostatic pressure inside the cell increases, which forces the plasmalemma to press against the cell wall. The cell wall, in turn, exerts a counterpressure, which is characterized by pressure potential(Ψ pressure) or hydrostatic potential, it is usually positive and the greater, the more water in the cell.

Thus, the water potential of the cell depends on the concentration of osmotically active substances - the osmotic potential (Ψ osm.) And the pressure potential (Ψ pressure).

Provided that water does not press on the cell wall (the state of plasmolysis or wilting), the back pressure of the cell wall is zero, the water potential is equal to the osmotic:

Ψ in. = Ψ osm.

As water enters the cell, the backpressure of the cell membrane appears, the water potential will be equal to the difference between the osmotic potential and the pressure potential:

Ψ in. = Ψ osm. + Ψ pressure

The difference between the osmotic potential of the cell sap and the backpressure of the cell membrane determines the flow of water at any given moment.

Under the condition that the cell membrane is stretched to the limit, the osmotic potential is completely balanced by the counterpressure of the cell membrane, the water potential becomes zero, and water ceases to flow into the cell:

- Ψ osm. = Ψ pressure , Ψ c. = 0

Water always flows in the direction of a more negative water potential: from the system where the energy is greater to the system where the energy is less.

Water can also enter the cell due to swelling forces. Proteins and other substances that make up the cell, having positively and negatively charged groups, attract water dipoles. The cell wall, which contains hemicelluloses and pectin substances, and the cytoplasm, in which high-molecular polar compounds make up about 80% of the dry mass, are capable of swelling. Water penetrates into the swelling structure by diffusion, the movement of water follows a concentration gradient. The force of swelling is denoted by the term matrix potential(Ψ mat.). It depends on the presence of high-molecular components of the cell. The matrix potential is always negative. Large value of Ψ mat. has when water is absorbed by structures in which there are no vacuoles (seeds, meristem cells).

Water is the most common compound on Earth and in living organisms. The water content in cells depends on the nature of metabolic processes: the more intense they are, the higher the water content.

On average, the cells of an adult human contain 60-70% water. With the loss of 20% of water, organisms die. Without water, a person can live no more than 7 days, while without food no more than 40 days.

Rice. 4.1. The spatial structure of the water molecule (H 2 O) and the formation of a hydrogen bond

The water molecule (H 2 O) consists of two hydrogen atoms that are covalently bonded to oxygen atoms. The molecule is polar because it is bent at an angle and the nucleus of the oxygen atom pulls the shared electrons to this angle, so that the oxygen acquires a partial negative charge, and the hydrogen atoms at the open ends become partially positive charges. Water molecules can be attracted to each other by positive and negative charges, forming hydrogen bond (Fig.4.1.).

Due to the unique structure of water molecules and their ability to bind to each other using hydrogen bonds, water has a number of properties that determine its important role in the cell and organism.

Hydrogen bonds cause relatively high boiling and evaporation temperatures, high heat capacity and thermal conductivity of water, and the property of a universal solvent.

Hydrogen bonds are 15-20 times weaker than covalent bonds. In the liquid state, hydrogen bonds are either formed or broken, which causes the movement of water molecules, its fluidity.

The biological role of H 2 O

Water determines the physical properties of the cell - its volume, elasticity (turgor). The cell contains 95-96% free water and 4-5% bound. Bound water forms aqueous (solvate) shells around certain compounds (for example, proteins), preventing their interaction with each other.

free water is a good solvent for many inorganic and organic polar substances. Substances that are highly soluble in water are called hydrophilic. For example, alcohols, acids, gases, most salts of Sodium, Potassium, etc. For hydrophilic substances, the binding energy between their atoms is less than the energy of attraction of these atoms to water molecules. Therefore, their molecules or ions are easily integrated into the general system of hydrogen bonds of water.

Water as a universal solvent plays an extremely important role, since most chemical reactions occur in aqueous solutions. The penetration of substances into the cell and the removal of waste products from it in most cases is possible only in dissolved form.

Water does not dissolve non-polar (non-charged) substances, since it cannot form hydrogen bonds with them. Substances that are insoluble in water are called hydrophobic . These include fats, fat-like substances, polysaccharides, rubber.

Some organic molecules have dual properties: in some areas they are polar groups, and in others - non-polar. Such substances are called amphipathic, or amphiphilic. These include proteins, fatty acids, phospholipids, nucleic acids. Amphiphilic compounds play an important role in the organization of biological membranes, complex supramolecular structures.

Water is directly involved in the reactions hydrolysis- breakdown of organic compounds. At the same time, under the action of special enzymes, OH ions are added to the free valences of organic molecules. - and H + water. As a result, they form new substances with new properties.

Water has a high heat capacity (i.e., the ability to absorb heat with minor changes in its own temperature) and good thermal conductivity. Due to these properties, the temperature inside the cell (and the body) is maintained at a certain level with significant changes in ambient temperature.

An important biological significance for the functioning of plants and cold-blooded animals is that under the influence of dissolved substances (carbohydrates, glycerol) water can change its properties, in particular the freezing and boiling points.

The properties of water are so important for living organisms that it is impossible to imagine the existence of life, as we know it, not only on Earth, but on any other planet without an adequate supply of water.

MINERAL SALT

They can be in a dissolved or undissolved state. Molecules of mineral salts in an aqueous solution decompose into cations and anions.

Water is contained in living cells, in the dead elements of the xylem and in the intercellular spaces. In the intercellular spaces, water is in a vapor state. Leaves are the main evaporating organs of a plant. In this regard, it is natural that the largest amount of water fills the intercellular spaces of the leaves. In a liquid state, water is found in various parts of the cell: cell membrane, vacuole, cytoplasm. Vacuoles are the most water-rich part of the cell, where its content reaches 98%. At the highest water content, the water content in the cytoplasm is 95%. The lowest water content is characteristic of cell membranes. Quantitative determination of water content in cell membranes is difficult; apparently, it ranges from 30 to 50%.

The forms of water in different parts of the plant cell are also different. The vacuolar cell sap is dominated by water retained by relatively low molecular weight compounds (osmotically bound) and free water. In the shell of a plant cell, water is mainly bound by high-polymer compounds (cellulose, hemicellulose, pectin substances), i.e., colloidally bound water. In the cytoplasm itself there is free water, colloidally and osmotically bound. Water located at a distance of up to 1 nm from the surface of a protein molecule is firmly bound and does not have a regular hexagonal structure (colloidal-bound water). In addition, there is a certain amount of ions in the cytoplasm, and, consequently, part of the water is osmotically bound.

The physiological significance of free and bound water is different. According to most researchers, the intensity of physiological processes, including growth rates, depends primarily on the content of free water. There is a direct correlation between the content of bound water and the resistance of plants to adverse external conditions. These physiological correlations are not always observed.

For their normal existence, cells and the plant organism as a whole must contain a certain amount of water. However, this is easily feasible only for plants growing in water. For land plants, this task is complicated by the fact that water in the plant organism is continuously lost in the process of evaporation. Evaporation of water by the plant reaches enormous proportions. An example can be given: one corn plant evaporates up to 180 kg of water during the growing season, and 1 hectare of forest in South America evaporates an average of 75 thousand kg of water per day. The huge water consumption is due to the fact that most plants have a significant leaf surface located in an atmosphere that is not saturated with water vapor. At the same time, the development of an extensive leaf surface is necessary and developed in the course of a long evolution to ensure normal nutrition with carbon dioxide contained in the air in an insignificant concentration (0.03%). In his famous book "The fight of plants against drought" K.A. Timiryazev pointed out that the contradiction between the need to capture carbon dioxide and reduce water consumption left an imprint on the structure of the entire plant organism.

In order to compensate for the loss of water during evaporation, a large amount of it must continuously enter the plant. Two processes continuously going on in a plant - the inflow and evaporation of water - are called plant water balance. For the normal growth and development of plants, it is necessary that the water consumption approximately correspond to the income, or, in other words, that the plant reduces its water balance without a large deficit. To do this, in the process of natural selection, the plant developed adaptations to absorb water (a colossally developed root system), to move water (a special conductive system), to reduce evaporation (the system of integumentary tissues and the system of automatically closing stomatal openings).

Despite all these adaptations, a water deficit is often observed in the plant, i.e., the intake of water is not balanced by its consumption in the process of transpiration.

Physiological disturbances occur in different plants with varying degrees of water deficiency. There are plants that have developed in the process of evolution various adaptations to tolerate dehydration (drought-resistant plants). The elucidation of the physiological characteristics that determine the resistance of plants to a lack of water is a most important task, the solution of which is of great not only theoretical, but also agricultural practical importance. At the same time, in order to solve it, knowledge of all aspects of the water exchange of a plant organism is necessary.

About 100 chemical elements are found in the earth's crust, but only 16 of them are necessary for life. The most common in plant organisms are four elements - hydrogen, carbon, oxygen, nitrogen, which form various substances. The main components of a plant cell are water, organic and mineral substances.

Water- the basis of life. The water content in plant cells ranges from 90 to 10%. It is a unique substance due to its chemical and physical properties. Water is necessary for the process of photosynthesis, transport of substances, cell growth, it is a medium for many biochemical reactions, a universal solvent, etc.

Minerals (ash)- substances that remain after burning a piece of an organ. The content of ash elements ranges from 1% to 12% dry weight. Almost all the elements that make up water and soil are found in the plant. The most common are potassium, calcium, magnesium, iron, silicon, sulfur, phosphorus, nitrogen (macroelements) and copper, aluminum, chlorine, molybdenum, boron, zinc, lithium, gold (microelements). Minerals play an important role in the life of cells - they are part of amino acids, enzymes, ATP, electron transport chains, are necessary for membrane stabilization, participate in metabolic processes, etc.

organic matter plant cells are divided into: 1) carbohydrates, 2) proteins, 3) lipids, 4) nucleic acids, 5) vitamins, 6) phytohormones, 7) products of secondary metabolism.

Carbohydrates make up to 90% of the substances that make up the plant cell. Distinguish:

Monosaccharides (glucose, fructose). Monosaccharides are formed in the leaves during photosynthesis and are easily converted into starch. They accumulate in fruits, less often in stems, bulbs. Monosaccharides are transported from cell to cell. They are an energy material, participate in the formation of glycosides.

Disaccharides (sucrose, maltose, lactose, etc.) are formed from two particles of monosaccharides. They accumulate in roots and fruits.

Polysaccharides are polymers that are very widespread in plant cells. This group of substances includes starch, inulin, cellulose, hemicellulose, pectin, callose.

Starch is the main storage substance of a plant cell. Primary starch is formed in chloroplasts. In the green parts of the plant, it is split into mono- and disaccharides and transported along the phloem of the veins to the growing parts of the plant and storage organs. In the leukoplasts of the storage organs, secondary starch is synthesized from sucrose in the form of starch grains.

The starch molecule is composed of amylose and amylopectin. Linear amylose chains, consisting of several thousand glucose residues, are able to branch helically and thus take on a more compact form. In the branched polysaccharide amylopectin, compactness is ensured by intensive chain branching due to the formation of 1,6-glycosidic bonds. Amylopectin contains approximately twice as many glucose residues as amylose.

With Lugol's solution, an aqueous suspension of amylose gives a dark blue color, amylopectin suspension - red-violet, starch suspension - blue-violet.

Inulin is a polymer of fructose, a storage carbohydrate of the aster family. It is found in cells in a dissolved form. Does not stain with iodine solution, stains red with β-naphthol.

Cellulose is a polymer of glucose. Cellulose contains about 50% of the carbon in the plant. This polysaccharide is the main material of the cell wall. Cellulose molecules are long chains of glucose residues. A plurality of OH groups protrude from each chain. These groups are directed in all directions and form hydrogen bonds with neighboring chains, which provides a rigid cross-linking of all chains. Chains are combined with each other, forming microfibrils, and the latter are combined into larger structures - macrofibrils. The tensile strength of this structure is very high. Macrofibrils, located in layers, are immersed in a cementing matrix consisting of pectin substances and hemicelluloses.

Cellulose does not dissolve in water, with a solution of iodine it gives a yellow color.

Pectins are composed of galactose and galacturonic acid. Pectic acid is a polygalacturonic acid. They are part of the cell wall matrix and provide its elasticity. Pectins form the basis of the median lamina, which is formed between cells after division. Form gels.

Hemicelluloses are macromolecular compounds of mixed composition. They are part of the cell wall matrix. They do not dissolve in water, hydrolyze in an acidic environment.

Callose is an amorphous polymer of glucose found in various parts of the plant body. Callose is formed in the sieve tubes of the phloem, and is also synthesized in response to damage or adverse effects.

Agar-agar is a high molecular weight polysaccharide found in seaweed. It dissolves in hot water, and after cooling it hardens.

Squirrels macromolecular compounds consisting of amino acids. Elemental composition - C, O, N, S, P.

Plants are able to synthesize all amino acids from simpler substances. The 20 basic amino acids make up the entire variety of proteins.

The complexity of the structure of proteins and the extreme diversity of their functions make it difficult to create a single clear classification of proteins on any one basis. By composition, proteins are classified into simple and complex. Simple - consist only of amino acids, complex - consist of amino acids and non-protein material (prosthetic group).

Simple proteins include albumins, globulins, histones, prolamins, and glutenins. Albumins are neutral proteins, soluble in water, rarely found in plants. Globulins are neutral proteins, insoluble in water, soluble in dilute saline solutions, distributed in seeds, roots, stems of plants. Histones are neutral proteins, soluble in water, localized in the nuclei of all living cells. Prolamins - soluble in 60-80% ethanol, found in cereal grains. Glutenins are soluble in alkali solutions, are found in grains of cereals, green parts of plants.

The complex ones include phosphoproteins (the prosthetic group is phosphoric acid), lycoproteins (carbohydrate), nucleoproteins (nucleic acid), chromoproteins (pigment), lipoproteins (lipid), flavoproteins (FAD), metalloproteins (metal).

Proteins play an important role in the life of a plant organism and, depending on the function performed, proteins are divided into structural proteins, enzymes, transport proteins, contractile proteins, storage proteins.

Lipids- organic substances insoluble in water and soluble in organic solvents (ether, chloroform, benzene). Lipids are divided into true fats and lipoids.

True fats are esters of fatty acids and some kind of alcohol. They form an emulsion in water, hydrolyze when heated with alkalis. They are reserve substances, accumulate in seeds.

Lipoids are fat-like substances. These include phospholipids (they are part of the membranes), waxes (they form a protective coating on leaves and fruits), sterols (they are part of the protoplasm, participate in the formation of secondary metabolites), carotenoids (red and yellow pigments, necessary to protect chlorophyll, give color fruits, flowers), chlorophyll (the main pigment of photosynthesis)

Nucleic acids- the genetic material of all living organisms. Nucleic acids (DNA and RNA) are made up of monomers called nucleotides. A nucleotide molecule consists of a five-carbon sugar, a nitrogenous base, and phosphoric acid.

vitamins- complex organic substances of various chemical composition. They have a high physiological activity - they are necessary for the synthesis of proteins, fats, for the operation of enzymes, etc. Vitamins are divided into fat-soluble and water-soluble. Fat-soluble vitamins include vitamins A, K, E, and water-soluble vitamins C and B vitamins.

Phytohormones- low molecular weight substances with high physiological activity. They have a regulatory effect on the processes of growth and development of plants in very low concentrations. Phytohormones are divided into stimulants (cytokinins, auxins, gibberellins) and inhibitors (ethylene and abscisins).

The vital activity of cells, tissues and organs of plants is due to the presence of water. Water is a constitutional substance. Determining the structure of the cytoplasm of cells and its organelles, due to the polarity of the molecules, it is a solvent for organic and inorganic compounds involved in metabolism, and acts as a background environment in which all biochemical processes take place. Easily penetrating through the shells and membranes of cells, water circulates freely throughout the plant, ensuring the transfer of substances and thus contributing to the unity of the metabolic processes of the body. Due to its high transparency, water does not interfere with the absorption of solar energy by chlorophyll.

The state of water in plant cells

Water in the cell is presented in several forms, they are fundamentally different. The main ones are constitutional, solvate, capillary and reserve water.

Some of the water molecules entering the cell form hydrogen bonds with a number of radicals of organic molecules. Hydrogen bonds are especially easy to form such radicals:

This form of water is called constitutional . It is contained by a cell with a strength of up to 90 thousand barr.

Due to the fact that water molecules are dipoles, they form solid aggregates with charged molecules of organic substances. Such water, associated with the molecules of organic substances of the cytoplasm by the forces of electrical attraction, is called solvate . Depending on the type of plant cell, the solvate water accounts for 4 to 50% of its total amount. Solvate water, like constitutional water, has no mobility and is not a solvent.

Much of the cell's water is capillary , because it is located in the cavities between macromolecules. Solvate and capillary water is held by the cell with a force called the matrix potential. It is equal to 15-150 bar.

Reserve called the water inside the vacuoles. The content of vacuoles is a solution of sugars, salts and a number of other substances. Therefore, the reserve water is retained by the cell with a force that is determined by the magnitude of the osmotic potential of the vacuolar content.

Water uptake by plant cells

Since there are no active carriers for water molecules in cells, its movement into and out of cells, as well as between neighboring cells, is carried out only according to the laws of diffusion. Therefore, solute concentration gradients turn out to be the main drivers for water molecules.

Plant cells, depending on their age and condition, absorb water using the sequential inclusion of three mechanisms: imbibition, solvation and osmosis.

imbibition . When seeds germinate, it begins to absorb water due to the imbibition mechanism. In this case, the vacant hydrogen bonds of the organic substances of the protoplast are filled, and water actively enters the cell from the environment. Compared to other forces operating in cells, the imbibition forces are colossal. For some hydrogen bonds, they reach a value of 90 thousand barr. At the same time, the seeds can swell and germinate in relatively dry soils. After all vacant hydrogen bonds are filled, imbibition stops and the following mechanism of water absorption is activated.

solvation . In the process of solvation, water absorption occurs by building hydration layers around the molecules of protoplast organic substances. The total water content of the cell continues to increase. The intensity of solvation essentially depends on the chemical composition of the protoplast. The more hydrophilic substances in the cell, the more fully the solvation forces are used. Hydrophilicity decreases in the series: proteins -> carbohydrates -> fats. Therefore, protein seeds (peas, beans, beans) absorb the largest amount of water per unit weight by solvation, starch seeds (wheat, rye) the intermediate one, and oilseeds (flax, sunflower) the smallest.

The solvation forces are inferior in power to the imbibition forces, but they are still quite significant and reach 100 bar. By the end of the solvation process, the water content of the cell is so great that capillary moisture settles down, and vacuoles begin to appear. However, from the moment of their formation, solvation stops, and further absorption of water is possible only due to the osmotic mechanism.

Osmosis . The osmotic mechanism of water uptake only works in cells that have a vacuole. The direction of water movement in this case is determined by the ratio of the osmotic potentials of the solutions included in the osmotic system.

The osmotic potential of the cell sap, denoted by R, is determined by the formula:

R = iRct,

where R - osmotic potential of cell sap

R- gas constant equal to 0.0821;

T - temperature on the Kelvin scale;

i- isotonic coefficient indicating the nature of the electrolytic dissociation of dissolved substances.

The isotonic ratio itself is equal to

and= 1 + α ( n + 1),

where α - degree of electrolytic dissociation;

P - the number of ions into which the molecule dissociates. For non-electrolytes P = 1.

The osmotic potential of a soil solution is usually denoted by the Greek letter π.

Water molecules always move from a medium with a lower osmotic potential to a medium with a higher osmotic potential. So, if the cell is in the soil (external) solution at R>π, then water enters the cells. The flow of water into the cell stops when the osmotic potentials are completely equalized (the vacuolar juice is diluted at the entrance of water absorption) or when the cell membrane reaches the limits of extensibility.

Thus, cells receive water from the environment only under one condition: the osmotic potential of the cell sap must be higher than the osmotic potential of the surrounding solution.

If R< π, there is an outflow of water from the cell into the external solution. In the course of fluid loss, the volume of the protoplast gradually decreases, it moves away from the membrane, and small cavities appear in the cell. Such a state is called Plasmolysis . The stages of plasmolysis are shown in fig. 3.18.

If the ratio of osmotic potentials corresponds to the condition P = π, then diffusion of water molecules does not occur at all.

A large amount of factual material indicates that the osmotic potential of the cell sap of plants varies within fairly wide limits. In agricultural plants, in root cells, it usually lies in an amplitude of 5-10 bar, in leaf cells it can rise up to 40 bar, and in fruit cells - up to 50 bar. In solonchak plants, the osmotic potential of cell sap reaches 100 bar.

Rice. 3.18.

A - a cell in a state of turgor; B - angular; B - concave; G - convex; D - convulsive; E - cap. 1 - shell; 2 - vacuole; 3 - cytoplasm; 4 - core; 5 - Hecht threads