Inorganic ions, or minerals, perform the following functions in the body:

1. Bioelectric function. This function is associated with the occurrence of a potential difference across cell membranes. The ion concentration gradient on both sides of the membrane creates a potential of the order of 60-80 mV in different cells. The inner side of the cell membrane is negatively charged relative to the outer. The electrical potential of the membrane is the higher, the greater the protein content and its ionization (negative charge) inside the cell and the concentration of cations outside the cell (diffusion of Na + and K + ions through the membrane into the cell is difficult). This function of inorganic ions is used to regulate the functions of especially excitable cells (nerve, muscle) and to conduct nerve impulses.

2. Osmotic function used to regulate osmotic pressure. A living cell obeys the law of isoosmopolarity: in all environments of the body, between which there is a free exchange of water, the same osmotic pressure is established. If the number of ions in some medium increases, then water rushes after them until a new equilibrium and a new level of osmotic pressure are established.

3. Structural function due to the complexing properties of metals. Metal ions interact with anionic groups of proteins, nucleic acids, and other macromolecules, and thus provide, along with other factors, the maintenance of certain conformations of these molecules. Since the biological activity of biopolymers depends on their conformations, the normal implementation of their functions by proteins, the unimpeded realization of information embedded in nucleic acids, the formation of supramolecular complexes, the formation of subcellular structures, and other processes are unthinkable without the participation of cations and anions.

4. Regulatory function is that metal ions are activators of enzymes and thereby regulate the rate of chemical transformations in the cell. This is a direct regulatory action of cations. Indirectly, metal ions are often required for the action of another regulator, such as a hormone. Let's take a few examples. The formation of the active form of insulin is impossible without zinc ions. The tertiary structure of RNA is largely determined by the ionic strength of the solution, and cations such as Cr 2+ , Ni 2+ , Fe 2+ , Zn 2+ , Mn 2+ and others are directly involved in the formation of the helical structure of nucleic acids. The concentration of Mg 2+ ions affects the formation of such a supramolecular structure as ribosomes.

5. Transport function manifests itself in the participation of certain metals (in the composition of metalloproteins) in the transfer of electrons or simple molecules. For example, iron and copper cations are part of cytochromes, which are electron carriers in the respiratory chain, and iron in hemoglobin binds oxygen and participates in its transfer.

6. Energy function associated with the use of phosphate anions in the formation of ATP and ADP (ATP is the main energy carrier in living organisms).

7. Mechanical function. For example, Ca +2 cation and phosphate anion are part of hydroxylapatite and calcium phosphate of bones and determine their mechanical strength.

8. Synthetic function. Many inorganic ions are used in the synthesis of complex molecules. For example, iodine ions I¯ are involved in the synthesis of iodothyronines in thyroid cells; anion (SO 4) 2- - in the synthesis of ether-sulfur compounds (during the neutralization of harmful organic alcohols and acids in the body). Selenium plays an important role in the mechanism of protection against the toxic effects of peroxide. It forms selenocysteine, an analogue of cysteine, in which selenium atoms replace sulfur atoms. Selenocysteine ​​is a component of the glutathione peroxidase enzyme, which catalyzes the reduction of hydrogen peroxide by glutathione (tripeptide - γ-glutamyl-cysteinylglycine)

It is important to note that interchangeability of some ions is possible within certain limits. With a lack of some metal ion, it can be replaced by an ion of another metal, similar in physicochemical properties and ionic radius. For example, a sodium ion is replaced by a lithium ion; calcium ion - strontium ion; molybdenum ion - vanadium ion; iron ion - cobalt ion; sometimes magnesium ions - manganese ions.

Due to the fact that minerals activate the action of enzymes, they affect all aspects of metabolism. Let us consider how the dependence of the exchange of nucleic acids, proteins, carbohydrates and lipids on the presence of certain inorganic ions is expressed.

Goals:

Educational:

• Systematization of knowledge about the chemical composition of the cell.
• Consolidation of knowledge about chemical elements and their role in the cells of living organisms, the chemical community of animate and inanimate nature.
• Awareness of the role of chemicals for the normal functioning of the human body.

Educational:

• the formation of a worldview, an active life position, the experience of correct behavior and communication, the transformation of these valuable properties into stable moral qualities of a person, the formation of readiness for self-education and mental development; educate the subject competence of students. Instill hygiene habits for a healthy lifestyle.

Developing:

• development of intelligence, attention, perception, memory, thinking, imagination, speech, emotional-volitional sphere of schoolchildren; highlighting the most important, dominant tasks of the lesson, their concretization, taking into account the characteristics and capabilities of the team.

Equipment: scheme "Chemical elements", pictures depicting plants and animals, signs of chemical elements, flour, tripod, glass rod, porcelain cup.

Tasks:

1. Describe the unity of the chemical composition of living organisms and inanimate nature.
2. To reveal the role of minerals in the life of a cell of a living organism.

Lesson plan:

1. Testing knowledge on the topic "Methods of Cytology", "Cell Theory" (story, tests).
2. New topic:
   1. The chemical composition of the cell.
   2. Classification of minerals (according to the content in the cell).
   3. The role of macro and microelements in the life of the cell.
   4. The role of chemical elements in the human body.
3. Consolidation.
4. Homework.

During the classes

I. Knowledge check:

1. Methods and tasks of cytology.

2. Magnifiers. Light microscope device. How to find out the total magnification of a light microscope?

3. The history of the formation of cytology. The contribution of individual scientists to the development of cell theory.

4. Cards with tests:

Cell division discovered and established that each cell comes from the original by dividing:
a) Leeuwenhoek
b) R. Hooke
c) R. Brown
d) R. Vikhrov

The cellular structure of organisms of all kingdoms testifies to:
a) the unity of the organic world
b) the similarity of animate and inanimate nature
c) the origin of the living from the non-living
d) the similarity of the structure of bacteria, viruses, fungi.

The creators of the cell theory are:
a) Darwin and Wallace
b) Mendel and Morgan
c) Hooke and Leeuwenhoek
d) Schleiden and Schwann

Cell theory corresponds to the following statement:
A) cells reproduce by dividing
B) chromosomes - material carriers of heredity
C) all living things, except bacteria, have a cellular structure.
D) the cells of all living beings and viruses are similar in structure and function

What is the commonality between the conclusions of the cellular and atomic-molecular theories?
A) in establishing the unit of structure of the object
b) in the similarity of the structure of the objects of study
c) in the similarity of the properties of the objects of study

II. New topic: And now we will see a demo experience.

Demonstration experiment "Burning flour in a porcelain cup"

What substances are formed when flour is burned? What signs of a reaction did you observe?

Signs of a reaction:

• water droplets (water vapor condenses on a cold glass plate);
• smoke (organic substances burn);
• ash (inorganic matter). (Slide)

So, the composition of living organisms includes organic and inorganic substances, as well as water. Today in the lesson we will focus on the study of inorganic substances in the cells of living organisms, we will find out what role certain chemical elements play in the life processes of living organisms.

Listen, guys, lines from S. Shchipachev's poem "Reading Mendeleev":

There is nothing else in nature
Neither here nor there, in the depths of space:
Everything - from small grains of sand to planets -
It consists of single elements.

Guys, in the lessons of biology and chemistry, we have repeatedly made sure that we are surrounded by the world of chemical compounds. In any living organism, including the human body, many chemical reactions continuously occur. We can say that every living cell is a microscopic chemical laboratory. The intake of chemicals is carried out as a result of an important property of the cell - metabolism and energy.

Guys, let's remember and answer the following questions:

• What is called metabolism?
• What is the importance of metabolism?
• What are the main directions of metabolism?
• What is assimilation?
• What is called dissimilation?

Each type of organism is characterized by a special, genetically fixed type of metabolism. Any disease is accompanied by metabolic disorders, and genetically determined metabolic disorders are the cause of many hereditary diseases.

Many chemists are familiar with the winged words said in the 40s of the current century by the German scientists Walter and Ida Noddak that all the elements of the Periodic Table are present in every cobblestone on the pavement. At first, these words were not met with unanimous approval. However, as more and more precise methods for the analytical determination of chemical elements were developed, scientists became more and more convinced of the validity of these words.

If we agree that every cobblestone contains all the elements, then this should also be true for a living organism. All living organisms on Earth, including humans, are in close contact with the environment. Life requires constant metabolism in the body. The intake of chemical elements in the body is facilitated by food and consumed water.

Teacher: How many chemical elements does the modern periodic system of D.I. Mendeleev?

Of the 118 elements that exist in nature, more than 13 are of no importance for the functioning of living organisms, but 90 elements, to a greater or lesser extent, take part in the construction of a living organism and in the processes occurring in it. The main building materials are four elements: carbon, hydrogen, oxygen and nitrogen, and the rest, often being in very microscopic quantities in the body, affect health, and a deficiency or excess of any element is often the cause of a particular disease.

There are no special elements that are characteristic only for living organisms, and this is one of the proofs of the commonality of animate and inanimate nature. But the quantitative content of certain elements in living organisms and in the inanimate environment surrounding them differs significantly. For example, silicon in the soil is about 33%, and in land plants only 0.15%. Such differences indicate the ability of living organisms to accumulate only those elements that they need for life.

To study the quantitative composition of chemical elements contained in the cells of living organisms, we will carry out independent work using a textbook. Independent work of students (5 minutes).

• Write down the chemical elements that together make up 98% of the total contents of the cell.
• Write down the chemical elements, the content of which in the cell is calculated in tenths and hundredths of a percent.

Teacher: Guys, let's check the performance of independent work.

So, we have identified three groups of elements: macroelements - the share of which is 98% and microelements - the share of which is 1.9%, ultramicroelements, their concentration does not exceed 10-5%. These include uranium, radium, gold, silver, beryllium, selenium, and other rare elements.

Many chemical elements that make up the cell perform a specific function. Chemical elements that are part of the cell and perform biological functions are called biogenic. About 30 elements belong to biogenic elements. Among biogenic elements, a special place is occupied by the so-called elements - organogens, which form the most important substances in living organisms - water, proteins, fats, carbohydrates, vitamins, hormones, etc. Organogens include six elements - C, O, H, N, H, S.

A number of metals also belong to the number of biogenic elements, among which ten, the so-called “metals of life”, perform especially important biological functions. These metals are four s - elements C, K, Na, Mg and six d elements - Fe, Zn, Cu, Mn, Mo, Co.

Macroelements include oxygen (65-75%), carbon (15-18%), hydrogen (8-10%), nitrogen (2.0-3.0%), potassium (0.15-0.4%) , sulfur (0.15-0.2%), phosphorus (0.2-1.0%), chlorine (0.05-0.1%), magnesium (0.02-0.03%), sodium (0.02-0.03%), calcium (0.04-2.00%), iron (0.01-0.015%. Elements such as C, O, H, N, S, P are part of organic compounds.

And now we will listen to students' speeches about the role of macronutrients in the cell and in the body of plants, animals and humans. During the speech of the comrades, we fill out the table in notebooks. (Slide)

1. Oxygen - is a part of almost all organic substances of the cell. Formed during photosynthesis during the photolysis of water. For aerobic organisms, it serves as an oxidizing agent during cellular respiration, providing cells with energy. In the largest quantities in living cells is contained in the composition of water. It is not only an essential part of the air we breathe and drinking water, it also occupies a significant place in our body. With 65% of our total body mass, oxygen is the most important chemical element in the composition of the human body.
2. Carbon - is a part of all organic substances; a skeleton of carbon atoms forms their basis. In addition, in the form of CO2 it is fixed during photosynthesis and released during respiration, in the form of CO (in low concentrations) it is involved in the regulation of cellular functions, in the form of CaCO3 it is part of the mineral skeletons.
3. Hydrogen, like oxygen, is an integral element of air and drinking water. And it also applies to the main components of the human body. 10% of our weight is hydrogen. Hydrogen - is a part of all organic substances of the cell. It is found in the highest concentrations in water. Some bacteria oxidize molecular hydrogen for energy.
4. Nitrogen - is a part of proteins, nucleic acids and their monomers - amino acids and nucleotides. It is excreted from the body of animals in the composition of ammonia, urea, guanine or uric acid as the end product of nitrogen metabolism. In the form of nitric oxide, NO (in low concentrations) is involved in the regulation of blood pressure. Although nitrogen is also found in the air, it is better known as a heat transfer fluid, in liquid form. Still, its mysteriously evaporating gases should not be misleading - 3% of our body mass is made up of nitrogen.
5. Can sulfur, with its unpleasant appearance and smell, be important for our body? Yes, that's right. Sulfur is an essential constituent of amino acids and coenzymes. Sulfur - is part of the sulfur-containing amino acids, therefore it is found in most proteins. It is present in small amounts as a sulfate ion in the cytoplasm of cells and intercellular fluids.
6. Phosphorus, as a luminous substance, is known to everyone. But not everyone knows that it is thanks to phosphorus in the body that DNA is formed, the basis of human life. Phosphorus - is part of ATP, other nucleotides and nucleic acids (in the form of phosphoric acid residues), in bone tissue and tooth enamel (in the form of mineral salts), and is also present in the cytoplasm and intercellular fluids (in the form of phosphate ions).
7. Magnesium is vital for all organisms on earth, naturally for us humans, too. Despite its small fraction of 0.05% of our body weight, a lack of magnesium leads to distinctly tangible consequences: Nervousness, headaches, fatigue and muscle cramps are just some of them. Magnesium is a cofactor for many enzymes involved in energy metabolism and DNA synthesis; maintains the integrity of ribosomes and mitochondria, is part of chlorophyll. In animal cells, it is necessary for the functioning of muscle and bone systems.
8. Even if it is only 1.5%, calcium is an important metal in our body. It is he who gives strength to our bones and teeth. Calcium - is involved in blood coagulation, and also serves as one of the universal second messengers, regulating the most important intracellular processes (including participating in the maintenance of membrane potential, necessary for muscle contraction and exocytosis). Insoluble calcium salts are involved in the formation of bones and teeth of vertebrates and the mineral skeletons of invertebrates.
9. Sodium we consume primarily in the form of sodium chloride, also known as table salt. The element is important for the protection of cells and the movement of nerve signals. Sodium - is involved in maintaining the membrane potential, generating a nerve impulse, osmoregulation processes (including the functioning of the kidneys in humans) and creating a blood buffer system.
10. Potassium, with a modest 0.2%, takes little part in the processes of the body. It belongs to the electrolytes that our body needs, first of all, during sports. Its deficiency can cause a feeling of exhaustion and convulsions. Potassium - is involved in maintaining the membrane potential, generating a nerve impulse, regulating the contraction of the heart muscle. Contained in intercellular substances.

Teacher: The vital elements sodium and potassium work together. It has been reliably established that all living organisms are characterized by the phenomenon of ionic asymmetry - an uneven distribution of ions inside and outside the cell. For example, inside the cells of muscle fibers, heart, liver, kidneys, there is an increased content of potassium ions compared to extracellular. The concentration of sodium ions, on the contrary, is higher outside the cell than inside it. The presence of a concentration gradient of potassium and sodium is an experimentally established fact. Interestingly, as the body ages, the concentration gradient of potassium and sodium ions at the cell boundary decreases. When death occurs, the concentrations of potassium and sodium inside and outside the cell immediately equalize. The human body contains an average of about 140 g of potassium and about 100 g of sodium. With food, we consume daily from 1.5 to 7 g of potassium ions and from 2 to 15 g of sodium ions. The need for Na ions is so great that they must be specially added to food (in the form of table salt). A significant loss of sodium ions (they are excreted from the body with urine and sweat) adversely affects human health. Therefore, in hot weather, doctors recommend eating more salty foods. However, their excessive content in food causes a negative reaction of the body, for example, an increase in blood pressure.

Teacher: The content of elements in the body is explained by the following quatrains.

Our blood tastes a little salty -
It contains sodium chloride;
In the intercellular space, sodium-plus
Osmosis pressure for the cells will save.
Chloride ions reign in the stomach,
To supply hydrochloric acid
We provide - this is not a joke -
Protein foods break down tails.

The composition of the human body.

The French chemist G. Bertrand calculated that the body of a person weighing about 100 kg contains 63 kg of oxygen, 19 kg of carbon, 9 kg of hydrogen, 5 kg of nitrogen, 1 kg of calcium, 700 g of phosphorus, and 640 g of sulfur , sodium - 25o g, potassium - 220 g, chromium - 180 g, magnesium - 80 g, iron - 3 g, iodine - 0.03 g. Fluorine, bromine, manganese, copper - even less. Count

And now we will consider microelements Slide Microelements that make up from 0.001% to 0.000001% of the body weight of living beings include vanadium, germanium, iodine, cobalt, manganese, nickel, ruthenium, selenium, fluorine, copper, chromium, zinc.

Among all trace elements, the so-called irreplaceable trace elements are distinguished into a special group. Essential trace elements are microelements, the regular intake of which with food or water into the body is absolutely necessary for its normal functioning. Essential trace elements are part of enzymes, vitamins, hormones and other biologically active substances. Essential trace elements are: iron, iodine, copper, manganese, zinc, cobalt, molybdenum, selenium, chromium, fluorine.

Questions for the class:

• What diseases are caused by a lack of chemical elements in plant and animal organisms?
• What foods contain micronutrients?
• What is the biological role of trace elements?

You are invited to listen carefully to the messages prepared by your classmates and answer the questions above.

1. “The biological role of fluorine”

Fluorine is found in small amounts in living organisms. There are about 2.6 g of fluorine in the human body, of which 2.5 g is in the bones. The biological role of fluorine is that it is involved in the formation of teeth and bones, in metabolism and in the activation of certain enzymes. The normal intake of fluorine in the human body is from 2.5 to 3.5 mg per day. A decrease or increase in the amount of fluorine causes various diseases. Chronic poisoning with fluorine compounds causes the disease fluorosis.

Teacher: And I want to add a funny poem to what has been said

Research has proven
What is fluorine as a trace element
So important for tooth enamel
As for building cement.
It is known: with a lack of fluorine
Toothache comes on soon.
Excess fluoride is also bad:
You can stay without teeth.

2. “The biological role of cobalt”

Cobalt is a microelement that has a variety of effects on the life processes of plant, animal organisms and humans. The human body contains 0.03 g of cobalt, of which 14% is found in bones, 43% each in muscles and soft tissues. Most cobalt in the liver, kidneys and pancreas. The biological role of cobalt is great - it participates in the processes of hematopoiesis metabolism, affects protein, fat, carbohydrate, mineral metabolism, vitamin metabolism. For example, vitamin C, accelerates the synthesis of vitamin PP, is part of enzymes (peptidase).

Cobalt is an integral part of vitamin B12.

3. “The biological role of copper”

Copper is one of the most important trace elements involved in the processes of photosynthesis and affects the absorption of nitrogen by plants. The human body contains about 0.1 g of copper. The daily requirement of an adult is from 2 to 3 mg. Copper is concentrated in the liver, in the blood, in the brain, in the bones. Copper deficiency and its excess are equally harmful to the body. With a lack of copper in the human diet, the formation of hemoglobin decreases and anemia develops, bone formation is disturbed with changes in the skeleton. Excess copper accumulates in the liver, brain, kidneys, eyes and causes chronic inflammation in tissues.

Teacher: Thanks guys for the performances.

It turns out that it is possible to make an elemental portrait of any person that strictly corresponds to gender, age, constitution, temperament and, of course, lifestyle. The elemental “portrait” is that chemical composition, i.e. the content of macro- and microelements that we "carry" in ourselves. And if any changes occur in our life (organism), they also affect our elemental composition, which reacts very quickly to any collisions.

The exact diagnosis of stress, which is often the cause of the disease, can, it turns out, be established by the spectral composition of the hair. The concentration of all the chemical elements that are only in our body is much higher in the hair than in such biological fluids as are habitual for analysis, such as blood and urine. In addition, hair concentrates almost all the chemical elements that are contained in our body. For example, if it is possible to reliably obtain data on 6–8 elements from blood serum, then hair “give out” information on 20–30 elements. All analyzes are carried out using a plasma spectrometer. The results of the analysis are processed on a computer that retrieves from its memory information about the average norm of macro- and microelements for a healthy person of a given gender and age, compares the elemental composition of the patient's hair with them and evaluates deviations in the mineral composition. First of all, the content of such vital elements as calcium, potassium, iron, copper, magnesium, zinc is determined, because their functions are extremely important for our body.

According to the noted imbalance, a preliminary diagnosis is made, then a treatment program is determined, aimed at eliminating the deficiency of the missing element and removing harmful or excess substances from the body. Such a correction of the body's mineral metabolism can be carried out by compiling a special diet with the inclusion of products that contain significant amounts of the elements necessary for the normal functioning of your body (and the diet should be compiled only by specialists)

In the hair of a person who thinks a lot, as determined, there is more, in comparison with the rest, zinc and copper. Manganese, lead, titanium, copper and silver predominate in those with dark hair. Gray hair contains only nickel. Moreover, they are associated with wisdom.

Gold is also found in the hair. Moreover, according to its content, women are truly more precious than men. Although Genghis Khan allegedly had a whole tuft of golden hair at the back of his head.

Ultramicroelements make up less than 0.0000001% in the organisms of living beings, they include gold, silver have a bactericidal effect, mercury inhibits the reabsorption of water in the renal tubules, affecting enzymes. Platinum and cesium are also referred to ultramicroelements. Some also include selenium in this group; with its deficiency, cancer develops. Selenium is an essential trace element. At the same time, in case of an overdose, it is highly toxic, so its use as a dietary supplement causes great discussion in the circles of scientists.

The functions of ultramicroelements are still little understood.

• So, guys, what new did you learn in the lesson?
• What did you like?
• What didn't you like?
• What surprised you?

Grading.

From this lesson you will learn about the role of mineral compounds of micro and macro elements in the life of living organisms. You will get acquainted with the pH of the environment - pH, learn how this indicator is related to the physiology of the body, how the body maintains a constant pH of the environment. Find out the role of inorganic anions and cations in metabolic processes, learn more about the functions of Na, K and Ca cations in the body, as well as what other metals are part of our body and what their functions are.

Introduction

Topic: Fundamentals of Cytology

Lesson: Minerals and their role in cell life

1. Introduction. Minerals in the cell

Minerals make up from 1 to 1.5% of the fresh mass of the cell, and are in the cells in the form of salts dislocated into ions, or in the solid state (Fig. 1).

Rice. 1. Chemical composition of cells of living organisms

In the cytoplasm of any cell there are crystalline inclusions, which are represented by slightly soluble salts of calcium and phosphorus; in addition to them, there may be silicon oxide and other inorganic compounds that are involved in the formation of the supporting structures of the cell - in the case of the mineral skeleton of radiolarians - and the body, that is, they form the mineral substance of bone tissue.

2. Inorganic ions: cations and anions

Inorganic ions are important for the life of the cell (Fig. 2).

Rice. 2. Formulas of the main ions of the cell

Cations- potassium, sodium, magnesium and calcium.

anions- chloride anion, hydrogen carbonate anion, hydrogen phosphate anion, dihydrogen phosphate anion, carbonate anion, phosphate anion and nitrate anion.

Consider the meaning of ions.

Ions, located on opposite sides of cell membranes, form the so-called transmembrane potential. Many ions are unevenly distributed between the cell and the environment. Thus, the concentration of potassium ions (K+) in the cell is 20-30 times higher than in the environment; and the concentration of sodium ions (Na+) is ten times lower in the cell than in the environment.

Through existence concentration gradients, many vital processes are carried out, such as contraction of muscle fibers, excitation of nerve cells, and the transfer of substances through the membrane.

Cations affect the viscosity and fluidity of the cytoplasm. Potassium ions reduce viscosity and increase fluidity, calcium ions (Ca2+) have the opposite effect on the cell cytoplasm.

Anions of weak acids - bicarbonate anion (HCO3-), hydrophosphate anion (HPO42-) - are involved in maintaining the acid-base balance of the cell, that is pHenvironments. According to their reaction, solutions can be sour, neutral and main.

The acidity or basicity of a solution is determined by the concentration of hydrogen ions in it (Fig. 3).

Rice. 3. Determination of the acidity of the solution using a universal indicator

This concentration is expressed using the pH value, the length of the scale is from 0 to 14. Neutral pH is about 7. Acidic is less than 7. Basic is more than 7. You can quickly determine the pH of the medium using indicator papers or strips (see video) .

We dip the indicator paper into the solution, then remove the strip and immediately compare the color of the indicator zone of the strip with the colors of the standard comparison scale that is included in the kit, evaluating the similarity of the color and determining the pH value (see video).

3. pH of the medium and the role of ions in its maintenance

The pH value in a cell is approximately 7.

A change in pH in one direction or another has a detrimental effect on the cell, since the biochemical processes taking place in the cell immediately change.

Cellular pH is maintained by buffer properties its contents. A buffer solution is a solution that maintains a constant pH value of the medium. Typically, a buffer system consists of a strong and a weak electrolyte: a salt and a weak base or weak acid that form it.

The effect of a buffer solution is that it resists changes in the pH of the medium. A change in the pH of the medium can occur as a result of concentrating the solution or diluting it with water, acid or alkali. When acidity, that is, the concentration of hydrogen ions, increases, free anions, the source of which is salt, interact with protons and remove them from the solution. When acidity decreases, the tendency to release protons increases. In this way, the pH is maintained at a certain level, that is, the concentration of protons is maintained at a certain constant level.

Some organic compounds, in particular proteins, also have buffering properties.

Cations of magnesium, calcium, iron, zinc, cobalt, manganese are part of enzymes and vitamins (see video).

Metal cations are part of hormones.

Zinc is part of insulin. Insulin is a pancreatic hormone that regulates blood glucose levels.

Magnesium is part of chlorophyll.

Iron is part of hemoglobin.

With a lack of these cations, the vital processes of the cell are disrupted.

4. Metal ions as cofactors

The value of sodium and potassium ions

Sodium and potassium ions are distributed throughout the body, while sodium ions are mainly part of the intercellular fluid, and potassium ions are contained inside the cells: 95% of ions potassium contained inside cells, and 95% of ions sodium contained in intercellular fluids(Fig. 4).

Associated with sodium ions osmotic pressure fluids, water retention by tissues, and transport, or transport substances such as amino acids and sugars through the membrane.

Importance of calcium in the human body

Calcium is one of the most abundant elements in the human body. The bulk of calcium is found in bones and teeth. The fraction outside bone calcium is 1% of the total amount of calcium in the body. Extraosseous calcium affects blood clotting, as well as neuromuscular excitability and muscle fiber contraction.

Phosphate buffer system

The phosphate buffer system plays a role in maintaining the acid-base balance of the body, in addition, it maintains a balance in the lumen of the tubules of the kidneys, as well as intracellular fluid.

The phosphate buffer system consists of dihydrogen phosphate and hydrogen phosphate. Hydrophosphate binds, that is, neutralizes the proton. Dihydrogen phosphate releases a proton and interacts with alkaline products that enter the blood.

The phosphate buffer system is part of the blood buffer system (Fig. 5).

Blood buffer system

In the human body, there are always certain conditions for a shift in the normal reaction of the tissue environment, for example, blood, towards acidosis (acidification) or alkalosis (deoxidation - shifting the pH up).

Various products enter the blood, for example, lactic acid, phosphoric acid, sulfurous acid, formed as a result of the oxidation of organophosphorus compounds or sulfur-containing proteins. In this case, the reaction of the blood can shift towards acidic products.

When eating meat products, acidic compounds enter the bloodstream. When eating plant foods, bases enter the blood.

However, the pH of the blood remains at a certain constant level.

In the blood there are buffer systems that maintain the pH at a certain level.

The buffer systems of the blood include:

carbonate buffer system,

Phosphate buffer system,

hemoglobin buffer system,

Plasma protein buffer system (Fig. 6).

The interaction of these buffer systems creates a certain constant blood pH.

Thus, today we have considered minerals and their role in the life of the cell.

Homework

What chemicals are called minerals? What is the importance of minerals for living organisms? What substances are living organisms mainly composed of? What cations are found in living organisms? What are their functions? What anions are found in living organisms? What is their role? What is a buffer system? What buffer systems of blood do you know? What is the content of minerals in the body?

1. Chemical composition of living organisms.

2. Wikipedia.

3. Biology and medicine.

4. Educational center.

Bibliography

1. Kamensky A. A., Kriksunov E. A., Pasechnik V. V. General biology 10-11 class Bustard, 2005.

2. Biology. Grade 10. General biology. Basic level / P. V. Izhevsky, O. A. Kornilova, T. E. Loshchilina and others - 2nd ed., revised. - Ventana-Graf, 2010. - 224 pages.

3. Belyaev D.K. Biology grade 10-11. General biology. A basic level of. - 11th ed., stereotype. - M.: Education, 2012. - 304 p.

4. Agafonova I. B., Zakharova E. T., Sivoglazov V. I. Biology 10-11 class. General biology. A basic level of. - 6th ed., add. - Bustard, 2010. - 384 p.

A cell is not only a structural unit of all living things, a kind of brick of life, but also a small biochemical factory in which various transformations and reactions take place every fraction of a second. This is how the structural components necessary for the life and growth of the organism are formed: the mineral substances of the cell, water and organic compounds. Therefore, it is very important to know what will happen if one of them is not enough. What role do various compounds play in the life of these tiny, structural particles of living systems that are not visible to the naked eye? Let's try to understand this issue.

Classification of cell substances

All compounds that make up the mass of the cell, form its structural parts and are responsible for its development, nutrition, respiration, plastic and normal development, can be divided into three large groups. These are categories such as:

• organic;
• inorganic substances of the cell (mineral salts);
• water.

Often the latter is referred to the second group of inorganic components. In addition to these categories, you can designate those that are made up of their combination. These are metals that make up the molecule of organic compounds (for example, a hemoglobin molecule containing an iron ion is protein in nature).

Minerals of the cell

If we talk specifically about the mineral or inorganic compounds that make up each living organism, then they are also not the same both in nature and in quantitative content. Therefore, they have their own classification.

All inorganic compounds can be divided into three groups.

1. Macronutrients. Those whose content inside the cell is more than 0.02% of the total mass of inorganic substances. Examples: carbon, oxygen, hydrogen, nitrogen, magnesium, calcium, potassium, chlorine, sulfur, phosphorus, sodium.
2. Trace elements - less than 0.02%. These include: zinc, copper, chromium, selenium, cobalt, manganese, fluorine, nickel, vanadium, iodine, germanium.
3. Ultramicroelements - the content is less than 0.0000001%. Examples: gold, cesium, platinum, silver, mercury and some others.

You can also highlight several elements that are organogenic, that is, they form the basis of organic compounds from which the body of a living organism is built. These are elements such as:

• hydrogen;
• nitrogen;
• carbon;
• oxygen.

They build the molecules of proteins (the basis of life), carbohydrates, lipids and other substances. However, minerals are also responsible for the normal functioning of the body. The chemical composition of the cell is calculated in dozens of elements from the periodic table, which are the key to successful life. Only about 12 of all atoms do not play a role at all, or it is negligible and not studied.

Some salts are especially important, which must be ingested with food every day in sufficient quantities so that various diseases do not develop. For plants, this is, for example, sodium. For humans and animals, these are calcium salts, table salt as a source of sodium and chlorine, etc.

Water

The mineral substances of the cell are combined with water into a common group, therefore, it is impossible not to say about its significance. What role does it play in the body of living beings? Huge. At the beginning of the article, we compared the cell to a biochemical factory. So, all the transformations of substances that occur every second are carried out precisely in the aquatic environment. It is a universal solvent and medium for chemical interactions, synthesis and decay processes.

In addition, water is part of the internal environment:

• cytoplasm;
• cell sap in plants;
• blood in animals and humans;
• urine;
• saliva of other biological fluids.

Dehydration means death for all organisms without exception. Water is the living environment for a huge variety of flora and fauna. Therefore, it is difficult to overestimate the significance of this, it is truly infinitely great.

Macronutrients and their meaning

Mineral substances of a cell for its normal work are of great importance. First of all, this applies to macronutrients. The role of each of them has been studied in detail and has long been established. We have already listed which atoms make up the group of macroelements, so we will not repeat ourselves. Let us briefly outline the role of the main ones.

1. Calcium. Its salts are necessary for the supply of Ca 2+ ions to the body. The ions themselves are involved in the processes of blood arrest and clotting, provide cell exocytosis, as well as muscle contractions, including cardiac contractions. Insoluble salts are the basis of strong bones and teeth of animals and humans.
2. Potassium and sodium. Maintain the state of the cell, form the sodium-potassium pump of the heart.
3. Chlorine - is involved in ensuring the electroneutrality of the cell.
4. Phosphorus, sulfur, nitrogen - are components of many organic compounds, and also take part in the work of muscles, the composition of bones.

Of course, if we consider each element in more detail, then much can be said about its excess in the body, and about its deficiency. After all, both are harmful and lead to diseases of various kinds.

trace elements

The role of minerals in the cell, which belong to the group of microelements, is also great. Despite the fact that their content is very small in the cell, without them it will not be able to function normally for a long time. The most important of all the above atoms in this category are such as:

• zinc;
• copper;
• selenium;
• fluorine;
• cobalt.

A normal level of iodine is essential for maintaining thyroid function and hormone production. Fluorine is needed by the body to strengthen tooth enamel, and plants - to maintain elasticity and rich color of the leaves.

Zinc and copper are elements that make up many enzymes and vitamins. They are important participants in the processes of synthesis and plastic exchange.

Selenium is an active participant in the processes of regulation; it is an element necessary for the functioning of the endocrine system. Cobalt, on the other hand, has another name - vitamin B 12, and all compounds of this group are extremely important for the immune system.

Therefore, the functions of mineral substances in the cell, which are formed by microelements, are no less than those that are performed by macrostructures. Therefore, it is important to consume both of them in sufficient quantities.

Ultramicroelements

The mineral substances of the cell, which are formed by ultramicroelements, do not play such a significant role as those mentioned above. However, their long-term deficiency can lead to the development of very unpleasant, and sometimes very dangerous consequences for health.

For example, selenium is also included in this group. Its long-term deficiency provokes the development of cancerous tumors. Therefore, it is considered indispensable. But gold and silver are metals that have a negative effect on bacteria, destroying them. Therefore, inside the cells play a bactericidal role.

However, in general, it should be said that the functions of ultramicroelements have not yet been fully disclosed by scientists, and their significance remains unclear.

Metals and organic substances

Many metals are part of organic molecules. For example, magnesium is a coenzyme of chlorophyll, necessary for plant photosynthesis. Iron is part of the hemoglobin molecule, without which it is impossible to breathe. Copper, zinc, manganese and others are parts of the molecules of enzymes, vitamins and hormones.

Obviously, all these compounds are important for the body. It is impossible to attribute them completely to mineral ones, but it still follows in part.

Mineral substances of the cell and their meaning: grade 5, table

To summarize what we said during the article, we will compile a general table in which we will reflect what mineral compounds are and why they are needed. You can use it when explaining this topic to schoolchildren, for example, in the fifth grade.

Thus, the mineral substances of the cell and their significance will be learned by schoolchildren in the course of the main stage of education.

Consequences of a lack of mineral compounds

When we say that the role of minerals in the cell is important, we must give examples that prove this fact.

We list some diseases that develop with a lack or excess of any of the compounds indicated in the course of the article.

1. Hypertension.
2. Ischemia, heart failure.
3. Goiter and other diseases of the thyroid gland (Basedow's disease and others).
4. Anemia.
5. Wrong growth and development.
6. Cancer tumors.
7. Fluorosis and caries.
8. Blood diseases.
9. Disorder of the muscular and nervous system.
10. Indigestion.

Of course, this is not a complete list. Therefore, it is necessary to carefully monitor that the daily diet is correct and balanced.

The cell consists of organic and mineral substances.

Mineral composition of cells

Of the inorganic substances, the cell contains 86 elements of the Periodic Table, about 16-18 elements are vital for the normal existence of a living cell.

Among the elements are: organogens, macroelements, microelements and ultramicroelements.

Organogens

These are the substances that make up organic matter: oxygen, carbon, hydrogen and nitrogen.

Oxygen(65-75%) - contained in a huge number of organic molecules - proteins, fats, carbohydrates, nucleic acids. In the form of a simple substance (O2) it is formed in the process of oxygenic photosynthesis (cyanobacteria, algae, plants).

Functions: 1. Oxygen is a strong oxidizing agent (oxidizes glucose during cellular respiration, energy is released in the process)

2. Included in the organic substances of the cell

3. Included in the water molecule

Carbon(15-18%) - is the basis of the structure of all organic substances. In the form of carbon dioxide, it is released during respiration and absorbed during photosynthesis. May be in the form of CO - carbon monoxide. In the form of calcium carbonate (CaCO3) is part of the bones.

Hydrogen(8 - 10%) - like carbon, it is part of any organic compound. It also contains water.

Nitrogen(2 - 3%) - is part of amino acids, and hence proteins, nucleic acids, some vitamins and pigments. Fixed by bacteria from the atmosphere.

Macronutrients

Magnesium (0,02 - 0,03%)

1. In the cell - is part of enzymes, participates in DNA synthesis and energy metabolism

2. In plants - is part of chlorophyll

3. In animals - it is part of the enzymes involved in the functioning of muscle, nervous and bone tissues.

Sodium (0,02 - 0,03%)

1. In the cell - is part of the potassium-sodium channels and pumps

2. In plants - participates in osmosis, which ensures the absorption of water from the soil

3. In animals - participates in the work of the kidneys, maintaining heart rate, is part of the blood (NaCl), helps maintain acid-base balance

Calcium (0,04 - 2,0%)

1. In the cell - participates in the selective permeability of the membrane, in the process of connecting DNA to proteins

2. In plants - forms salts of pectin substances, gives hardness to the intercellular substance connecting plant cells, and also participates in the formation of intercellular contacts

3. In animals, it is part of the bones of vertebrates, shells of mollusks and coral polyps, participates in the formation of bile, increases the reflex excitability of the spinal cord and the center of salivation, participates in the synaptic transmission of a nerve impulse, in the processes of blood coagulation, is a necessary factor in reducing the striated muscles

Iron (0,02%)

1. In the cell - is part of the cytochromes

2. In plants - participates in the synthesis of chlorophyll, is part of the enzymes involved in respiration, are part of cytochromes

3. In animals - is part of hemoglobin

Potassium (0,15 - 0,4%)

1. In the cell - maintains the colloidal properties of the cytoplasm, is part of the potassium-sodium pumps and channels, activates enzymes involved in protein synthesis during glycolysis

2. In plants - participates in the regulation of water metabolism and photosynthesis

3. Necessary for the correct heart rhythm, participates in the conduction of a nerve impulse

Sulfur (0,15 - 0,2%)

1. In the cell - is part of some amino acids - cytine, cysteine ​​and methionine, forms disulfide bridges in the tertiary structure of the protein, is part of some enzymes and coenzyme A, is part of bacteriochlorophyll, some chemosynthetics use sulfur compounds to generate energy

2. In animals - is part of insulin, vitamin B1, biotin

Phosphorus (0,2 - 1,0%)

1. In the cell - in the form of phosphoric acid residues, it is part of DNA, RNA, ATP, nucleotides, coenzymes NAD, NADP, FAD, phosphorylated sugars, phospholipids and many enzymes, forms membranes as part of phospholipids

2. In animals - it is part of the bones, teeth, in mammals it is a component of the buffer system, maintains the acid balance of the tissue fluid relatively constant

Chlorine (0,05 - 0,1%)

1. In the cell - participates in maintaining the electrical neutrality of the cell

2. In plants - participates in the regulation of turgor pressure

3. In animals - participates in the formation of the osmotic potential of blood plasma, also in the processes of excitation and inhibition in nerve cells, is part of the gastric juice in the form of hydrochloric acid

trace elements

Copper

1. In the cell - is part of the enzymes involved in the synthesis of cytochromes

2. In plants - it is part of the enzymes involved in the reactions of the dark phase of photosynthesis

3. In animals - it is involved in the synthesis of hemoglobin, in invertebrates it is part of hemocyanins - oxygen carriers, in humans - it is part of the skin pigment - melanin

Zinc

1. Participates in alcoholic fermentation

2. In plants - it is part of the enzymes involved in the breakdown of carbonic acid and in the synthesis of plant hormones-auxins

Iodine

1. In vertebrates - is part of the thyroid hormones (thyroxine)

Cobalt

1. In animals - it is part of vitamin B12 (takes part in the synthesis of hemoglobin), its deficiency leads to anemia

Fluorine

1. In animals - gives strength to bones and tooth enamel

Manganese

1. In the cell - is part of the enzymes involved in respiration, oxidation of fatty acids, increases the activity of carboxylase

2. In plants - as part of enzymes, it participates in dark reactions of photosynthesis and in the reduction of nitrates

3. In animals - it is part of the phosphatase enzymes necessary for bone growth

Bromine

1. In the cell - is part of vitamin B1, which is involved in the breakdown of pyruvic acid

Molybdenum

1. In the cell - as part of enzymes, it participates in the fixation of atmospheric nitrogen

2. In plants - as part of enzymes, it participates in the work of stomata and enzymes involved in the synthesis of amino acids

Bor

1. Affects plant growth