Cell

From the point of view of the concept of living systems according to A. Lehninger.

A living cell is an isothermal system of organic molecules capable of self-regulation and self-reproduction, extracting energy and resources from the environment.

A large number of sequential reactions take place in a cell, the speed of which is regulated by the cell itself.

The cell maintains itself in a stationary dynamic state, far from equilibrium with the environment.

Cells function on the principle of minimal consumption of components and processes.

That. A cell is an elementary living open system capable of independent existence, reproduction and development. It is the elementary structural and functional unit of all living organisms.

Chemical composition of cells.

Of the 110 elements of Mendeleev’s periodic table, 86 were found to be constantly present in the human body. 25 of them are necessary for normal life, 18 of them are absolutely necessary, and 7 are useful. In accordance with the percentage content in the cell, chemical elements are divided into three groups:

Macroelements The main elements (organogens) are hydrogen, carbon, oxygen, nitrogen. Their concentration: 98 – 99.9%. They are universal components of organic cell compounds.

Microelements - sodium, magnesium, phosphorus, sulfur, chlorine, potassium, calcium, iron. Their concentration is 0.1%.

Ultramicroelements - boron, silicon, vanadium, manganese, cobalt, copper, zinc, molybdenum, selenium, iodine, bromine, fluorine. They affect metabolism. Their absence is the cause of diseases (zinc - diabetes mellitus, iodine - endemic goiter, iron - pernicious anemia, etc.).

Modern medicine knows facts about negative interactions between vitamins and minerals:

Zinc reduces copper absorption and competes with iron and calcium for absorption; (and zinc deficiency causes a weakening of the immune system and a number of pathological conditions on the part of the endocrine glands).

Calcium and iron reduce the absorption of manganese;

Vitamin E does not combine well with iron, and vitamin C does not combine well with B vitamins.

Positive interaction:

Vitamin E and selenium, as well as calcium and vitamin K, act synergistically;

Vitamin D is necessary for the absorption of calcium;

Copper promotes the absorption and increases the efficiency of iron use in the body.

Inorganic components of the cell.

Water– the most important component of the cell, the universal dispersion medium of living matter. Active cells of terrestrial organisms consist of 60–95% water. In resting cells and tissues (seeds, spores) there is 10 - 20% water. Water in the cell is in two forms - free and bound to cellular colloids. Free water is the solvent and dispersion medium of the colloidal system of protoplasm. Its 95%. Bound water (4–5%) of all cell water forms weak hydrogen and hydroxyl bonds with proteins.

Properties of water:

Water is a natural solvent for mineral ions and other substances.

Water is the dispersive phase of the colloidal system of protoplasm.

Water is the medium for cell metabolic reactions, because physiological processes occur in an exclusively aquatic environment. Provides reactions of hydrolysis, hydration, swelling.

Participates in many enzymatic reactions of the cell and is formed during metabolism.

Water is a source of hydrogen ions during photosynthesis in plants.

Biological significance of water:

Most biochemical reactions occur only in aqueous solution; many substances enter and exit cells in dissolved form. This characterizes the transport function of water.

Water provides hydrolysis reactions - the breakdown of proteins, fats, carbohydrates under the influence of water.

Due to the high heat of evaporation, the body is cooled. For example, sweating in humans or transpiration in plants.

The high heat capacity and thermal conductivity of water contributes to the uniform distribution of heat in the cell.

Due to the forces of adhesion (water - soil) and cohesion (water - water), water has the property of capillarity.

The incompressibility of water determines the stressed state of cell walls (turgor) and the hydrostatic skeleton in roundworms.

Minerals (minerals)- natural substances, approximately homogeneous in chemical composition and physical properties, included in the composition of rocks, ores, meteorites (from the Latin minera - ore).

Minerals, along with proteins, fats, carbohydrates and vitamins, are vital components of human food, necessary for building the structures of living tissues and carrying out the biochemical and physiological processes that underlie the life of the body. Minerals participate in the body’s most important metabolic processes: water-salt and acid-base. Many enzymatic processes in the body are impossible without the participation of certain minerals.

The human body receives these elements from the environment, food and water.

The quantitative content of a particular chemical element in the body is determined by its content in the external environment, as well as by the properties of the element itself, taking into account the solubility of its compounds.

For the first time, the scientific foundations of the doctrine of microelements in our country were substantiated by V. I. Vernadsky (1960). Fundamental research was carried out by A.P. Vinogradov (1957) - the founder of the doctrine of biogeochemical provinces and their role in the occurrence of endemic diseases of humans and animals and V.V. Kovalsky (1974) - the founder of geochemical ecology and biogeography of chemical elements.

Currently, out of 92 naturally occurring elements, 81 chemical elements are found in the human body.

Minerals make up a significant portion of the human body by mass (on average, the body contains about 3 kg of ash). In bones, minerals are presented in the form of crystals, in soft tissues - in the form of a true or colloidal solution in combination mainly with proteins. For clarity, we can give the following example: the body of an adult contains about 1 kg of calcium, 0.5 kg of phosphorus, 150 g of potassium, sodium and chlorine, 25 g of magnesium, 4 g of iron.

• Classification of chemical elements
  • Classification of chemical elements according to their biological significance. All chemical elements can be divided into groups:
    • The 12 structural elements are carbon, oxygen, hydrogen, nitrogen, calcium, magnesium, sodium, potassium, sulfur, phosphorus, fluorine and chlorine.
    • 15 essential (vital) elements - iron, iodine, copper, zinc, cobalt, chromium, molybdenum, nickel, vanadium, selenium, manganese, arsenic, fluorine, silicon, lithium.
    • 2 conditionally necessary elements - boron and bromine.
    • 4 elements are serious "candidates for necessity" - cadmium, lead, aluminum and rubidium.
    • The remaining 48 elements are less significant for the body.
  • Classification of chemical elements based on a quantitative assessment of their content in the human body Traditionally, all mineral substances are divided into two groups according to their content in the human body.
    • Macroelements.
    • Microelements.

      The concentration of trace elements in the body is low. The body contains quantities measured in milligrams or micrograms. Trace elements are those minerals for which the estimated dietary requirement is typically less than 1 μg/g and often less than 50 ng/g of diet for laboratory animals and humans.

      Despite the low need, these elements are part of enzyme systems as coenzymes (activators and catalysts of biochemical processes). The group of microelements includes: zinc, iodine, fluorine, silicon, chromium, copper, manganese, cobalt, molybdenum, nickel, boron, bromine, arsenic, lead, tin, lithium, cadmium, vanadium and other substances.

• The influence of minerals on the human body.

  Minerals do not have energy value like proteins, fats and carbohydrates. However, without them, human life is impossible. Just as with a lack of basic nutrients or vitamins, with a deficiency of minerals in the human body, specific disorders arise, leading to characteristic diseases.

  Microelements and vitamins are in some ways even more important than nutrients, because without them the latter will not be properly absorbed by the body.

  Mineral substances are especially important for children during the period of intensive growth of bones, muscles, and internal organs. Naturally, pregnant women and nursing mothers need increased intake of minerals. With age, the need for minerals decreases.

  • Deficiency and excess intake of minerals

    The influence of micro- and macroelements on the vital functions of animals and humans is being actively studied for medical purposes. Any pathology, any deviation in the health of a biological organism is accompanied by either a deficiency of vital (essential) elements, or an excess of both essential and toxic microelements. This imbalance of macro- and microelements received the unifying name “microelementosis”.

    Since the 1970s, there have been many speculative claims that micronutrient deficiencies are a significant contributor to a number of chronic diseases. In many cases, this statement has been experimentally confirmed, but some scientists today believe that insufficient intake of a particular micronutrient is significant only when the body is exposed to stress, which increases the need for this micronutrient.

    Chemical substances, despite their importance and necessity for the human body, can also have a negative effect on plants, animals and humans if the concentration of their available forms exceeds certain limits. Cadmium, tin, lead and rubidium are considered conditionally necessary, because they appear to be of little importance to plants and animals and are hazardous to human health even at relatively low concentrations. The biological role of some trace elements is currently not sufficiently studied.

    It is necessary to remember certain precautions when consuming mineral complexes (both medications and biologically active food additives).

    An overdose of one mineral can lead to functional impairment and increased excretion of another mineral. The development of unwanted side effects is also possible. For example, excess zinc leads to a decrease in the level of cholesterol-containing high-density lipids ("good" cholesterol).

    Excess calcium can lead to phosphorus deficiency, and vice versa.

    Excess molybdenum reduces copper content.

    Some trace elements (selenium, chromium, copper) are toxic in excess doses. This especially applies to salts of many metals.

    When consuming minerals, you should strictly adhere to medical recommendations.

  • Effect of heavy metals on the human body

    In recent years, the effects of heavy metals on the human body have been isolated. Heavy metals are a group of chemical elements with a relative atomic mass greater than 40.

    The appearance of the term “heavy metals” in the literature was associated with the manifestation of the toxicity of certain metals and their danger to living organisms.

    However, the “heavy” group also includes some microelements, the vital necessity and wide range of biological effects of which have been irrefutably proven.

    “Heavy” metals are lead, cadmium, zinc, copper, nickel, chromium.

    In recent years, the important biological role of most “heavy” metals has been increasingly confirmed. Numerous studies have established that the influence of metals is very diverse and depends on their content in the environment and the degree of need for them by microorganisms, plants, animals and humans.

    The influence of “heavy” metals on living organisms is very diverse. This is due, firstly, to the chemical characteristics of metals, secondly, to the attitude of organisms towards them and, thirdly, to environmental conditions.

    Already now, in many regions of the world, the environment is becoming more and more “aggressive” from a chemical point of view. In recent decades, the main objects of biogeochemical research have become the territories of industrial cities and adjacent lands, especially if agricultural plants are grown on them and then used for food.

Modern scientific data on the biological role of the studied chemical elements, their metabolism in the human body, daily consumption rates, and the content of chemicals in food products are presented in separate articles describing each chemical element. The articles also present data on deficiency conditions that develop with insufficient consumption of these chemicals, as well as the body's response to excess consumption of nutrients.

• Macronutrients
  • Table salt

• Microelements

Abubekerova Alfiya, Tokareva Victoria, Matveeva Rimma, 8th grade students of the Municipal Educational Institution "Secondary School No. 1" in Nikolaevsk

The project presents the progress of work and the results obtained to clarify the role of chemical elements for living organisms. The album colorfully presents the biological role of the most important chemical elements.

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Municipal government educational institution

"Secondary school No. 1" of the city of Nikolaevsk, Nikolaev municipal district, Volgograd region

Project on the topic:

The work was completed by:

Tokareva Victoria, 8th grade

Matveeva Rimma, 8th grade

Abubekerova Alfiya, 8th grade

Supervisor:

Evdokimova A.S., teacher of chemistry and biology

Nikolaevsk, 2014

1.Introduction……………………………………………………………….. 3

2. Classification of chemical elements according to their functional role and content in the body………………………………………………. 5

3. The entry of chemical elements into the body…………………….6

4. Biological role of chemical elements…………………………7

5. The relationship of chemical elements………………………………… 7

6. Conclusions………………………………………………………………………………… 9

7. Result of work………………………………………………………9

9. Sources of information……………………………………………………………9

Application. …………………………………………………………………………………..11

1. Introduction.

Relevance

In 8th grade we started studying a new subject - chemistry. We learned that there are atoms of various chemical elements on Earth (there are more than 100 of them), each has its own name, and has its own place in D.I.’s Periodic Table of Chemical Elements. Mendeleev. It turns out that we often come across the names of many of them in everyday life. For example, television advertisements constantly encourage us to take vitamins containing calcium and preparations containing iodine . They also say that toothpaste with fluorine good for teeth and iron necessary for the normal functioning of our body. Why are these elements so necessary? Are other chemical elements important for living organisms? How many of them are required for normal functioning of the body? Where are they found, in what products? What happens if too much or very little of any element enters the body? We consider these issues to be very important for maintaining human health.

Problem : poor awareness of students about the biological role of chemical elements

Target - Find out the biological role of the most common chemical elements and use this information to develop in students a value-based attitude towards their health.

Tasks:

1. Determine the group of chemical elements most common on our planet and find out their biological significance.

2. Find out whether the combination and proportion of chemical elements when entering the body is important.

3. Present the information received in the form of a brochure or stand in the chemistry classroom.

4. Present this information at a chemistry lesson in front of your classmates.

Project type : informational (biology, chemistry)

Directions of project activity:

1. Analytical (information collection)
2. Creative (creating a brochure and stand)

3) Representative (creating a presentation, speaking in class)

Participants:

8th grade students

Project resource support:

Coordinator – chemistry teacher Anna Sergeevna Evdokimova.

Material resources: resources of the school mini-printing house, A4 paper, Whatman paper, double-sided tape, computer, Internet.

Implementation deadlines, stages of work on the project:

1. Statement of the problem, distribution of tasks, “roles” (January) 2014)
2. Collection of information (January – February 2014)
3. Summarizing the results, creating an album, designing a stand, (February 2014)

Result : increasing students' awareness of the biological role of chemical elements

Delayed result: developing a more responsible attitude towards one’s health

Practical significance(product): the information collected during the project will be presented in the form of a brochure, which can be used in preparation for exams, competitions, olympiads, and there will also be a stand in the chemistry classroom, where information about the biological role of chemicals will be presented in a bright, red and interesting way elements. Perhaps this information will not only encourage students to take more responsibility for their health, but will also increase interest in the subject of chemistry and help them decide on their choice of profession.

2. Classification of chemical elements according to their functional role and content in the body.

The biosphere contains 100 billion tons of living matter. About 50% of the mass of the earth's crust is oxygen, more than 25% is silicon. Eighteen elements (O, Si, Al, Fe, Ca. Na, K, Mg, H, Ti, C, P, N, S, Cl, F, Mn, Ba) make up 99.8% of the mass of the earth’s crust. Living organisms take an active part in the redistribution of chemical elements in the earth's crust. Minerals, natural chemical substances, are formed in the biosphere in various quantities due to the activity of living substances (the formation of iron ores, rocks based on calcium compounds). In addition, technogenic environmental pollution has an impact. Changes taking place inupper layers of the earth's crust, affect the chemical composition of living organisms. Almost all the elements that are found in the earth's crust and sea water can be found in the body. The content of some elements in the body is increased compared to the environment - this is called biological concentration of the element. For example, carbon in the earth's crust is 0.35%, and in terms of content in living organisms it ranks second (21%). However, this pattern is not always observed. Thus, silicon in the earth’s crust is 27.6%, but in living organisms there is little of it, aluminum - 7.45%, and in living organisms -1 10-5 %.

More than 70 elements have been found in living matter.

The elements necessary for the body to build and function cells and organs are callednutrients.

Biogenicity has been established for 30 elements. There are several classifications of nutrients:

A) According to their functional role:

1) organogens, 97.4% of them in the body (C, H, O, N, P, S),

2) elements of the electrolyte background (Na, K, Ca, Mg, Cl). These metal ions account for 99% of the total metal content in the body;

3) Microelements are biologically active atoms of the centers of enzymes and hormones.

B) Based on the concentration of elements in the body, biogenic elements are divided:

1) macroelements (their content exceeds 0.01% of body weight)

These include 12 elements: C, H, O, N, P, S, Na, K, Ca, Mg, Cl, Fe.

2) microelements (0.01% of body weight):Zinc , Iodine , Fluorine , Silicon , Chromium , Copper , Manganese , Cobalt , Molybdenum , Nickel , Bor , Bromine , Arsenic , Lead , Tin , Lithium , Cadmium , Vanadium , Selenium

3) ultramicroelements (their content is less than 10-5% of body weight).

3. The entry of chemical elements into the body.

All living organisms have close contact with the environment. Life requires constant metabolism in the body. The entry of chemical elements into the body is facilitated by nutrition and consumed water. The body consists of 60% water, 34% is organic matter and 6% is inorganic. The main components of organic substances are C, H, O. They also include N, P, S. The composition of inorganic substances necessarily contains 22 chemical elements. For example, if a person weighs 70 kg, then it contains (in grams): Ca - 1700, K - 250, Na –70, Mg - 42, Fe - 5, Zn - 3. Metals account for 2.1 kg . In accordance with the recommendation of the Dietetic Commission of the US National Academy, the daily intake of chemical elements from food should be at a certain level (Table No. 1).

Table 1. Daily intake of chemical elements into the human body

The same number of chemical elements must be excreted, since their content in the body is relatively constant.

The current state of knowledge about the biological role of elements can be characterized as a superficial touch on this problem. A lot of factual data has been accumulated on the content of elements in various components of the biosphere, and the body’s responses to their deficiency and excess.
If the element is insufficiently supplied to the body, significant damage is caused to the growth and development of the body. This is explained by a decrease in the activity of enzymes that contain the element. As the dose of this element increases, the body's response increases and reaches the norm (biotic concentration of the element). A further increase in the dose leads to a decrease in functioning due to the toxic effect of an excess of the element, including death. Deficiency and excess of a biogenic element harms the body. All living organisms react to deficiency and excess or unfavorable ratios of elements.

Conventional microelements, when their concentration in the body exceeds the biotic concentration, exhibit a toxic effect on the body. Toxic elements at very low concentrations do not have a harmful effect on plants and animals. For example, arsenic at microconcentrations has a biostimulating effect. Therefore, there are no toxic elements, but only toxic doses. Thus, small doses of an element are medicine, large doses are poison. “Everything is poison, and nothing is devoid of poisonousness; only one dose makes poison invisible” - Paracelsus. It is appropriate to recall the words of the Tajik poet Rudaki: “What is considered a drug today will become poison tomorrow.”

4 . Biological role of chemical elements.

Information on the biological role of chemical elements is indicated in the brochure “Biological role of chemical elements” (Appendix No. 1)

5. The relationship of chemical elements,

It is necessary to remember certain precautions when consuming mineral complexes (both medications and biologically active food additives).

An overdose of one mineral can lead to functional impairment and increased excretion of another mineral. The development of unwanted side effects is also possible. For example, excess zinc leads to a decrease in the level of cholesterol-containing high-density lipids ("good" cholesterol).

The main biological function of potassium is the formation, together with other electrolytes (sodium, chlorine), of a potential difference on cell membranes and the transmission of its changes along the cell membrane, due to exchange with sodium ions, which is especially important for nerve and muscle cells. This causes the constant presence of sodium, chlorine and potassium in the cells. In the body, these elements are contained in a certain ratio, ensuring homeostasis (constancy of the internal environment). An imbalance between potassium and sodium leads to pathology of water metabolism, dehydration, and muscle weakness.

Excess calcium can lead to phosphorus deficiency, and vice versa. Metabolism is so delicately structured that phosphorus works in close conjunction with calcium (normally, these substances should enter the body in approximately the same quantities; in extreme cases, phosphorus can be one and a half times more). In reality, modern foods contain much more of it than calcium. Scientists have calculated that, for example, the average American diet contains 2-4 times more phosphorus than calcium.Excess phosphorusstimulates the production of hormone by the parathyroid glands (these are four peas located next to the thyroid gland). Then this hormone begins to leach calcium from the bones. Osteoporosis develops - bones become brittle and brittle. Today in the world this disease has become an epidemic. A hip fracture in the elderly and the so-called “widow’s hump” are typical manifestations of osteoporosis. Fractures due to bone weakness occur even in teenagers. Serious studies have proven that girls who like to drink cola and other sodas (phosphoric acid is added to them) are 3.14 times more likely to have such fractures. And if they also play sports, then the risk of fractures is 5 times greater. The more phosphates in the blood, the higher the risk of heart attacks and mortality from cardiovascular diseases. Phosphorus helps the development of calcification. This is the most severe and irreversible damage to blood vessels, in which calcium is deposited on their inner wall, forming plaques as dense as bone.

Excess molybdenumreduces copper content.

Excess tungstenreduces molybdenum content.

Against the background of iron deficiency, as well as calcium, phosphorus, magnesium and zinc, the body’s ability to absorb lead increases, etc.

When consuming minerals, you should strictly adhere to medical recommendations!

6. Conclusions:

We found out that many chemical elements (more than 30) have a certain significance for living organisms. Elements such as C, H, O, N, P, S, being macroelements, play an important role; the cells of a living organism are built from them. Others, although they have low content in the body (microelements), are also necessary. But for most elements, both deficiency and excess have a harmful effect on the body.

We also figured out where the elements come from in our body, how to avoid excess and insufficient content of them.

There are elements, a small dose of which is toxic. These are elements such as arsenic, lead, mercury, cadmium, etc. Heavy metals have the ability to accumulate in the body.

The mutual influence of the exchange of one element on the exchange of another is also important. So, for example, phosphorus and calcium must enter the body in a certain ratio. If more phosphorus enters, this contributes to the leaching of calcium from bones and other consequences.

7. Result of work:

1) Found and summarized information about the biological role of chemical elements.

2) Created a brochure “Biological role of chemical elements” (Appendix No. 1)

3) Created a presentation on the biological role of chemical elements and presented it at a chemistry lesson in grades 8 and 9 (Appendix No. 2).

4) We set up a stand in the chemistry room (Appendix No. 3).

8. Sources of information:

1) Lecture notes on general chemistry. Chelyabinsk State Medical Academy. A. V. Zholnin.

2) Livanov P.A., Sobolev M.B., Revich B.A. Lead hazard and public health. // Ross. Sem. Doctor. 1999, No. 2, p. 18–26.

3) Korbanova A.I., Sorokina N.S., Molodkina N.N. Lead and its effect on

Organism. // Med. labor and industrial ecology. 2001, No. 5, p. 29–34.

4) Chemistry. Textbook for 9th grade. Gabrielyan O.S.

5) Internet resources:

wikipedia.org, etc.

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A2. Which scientist discovered the cell? 1) A. Leeuwenhoek 2) T. Schwann 3) R. Hooke 4) R. Virchow
A3. The content of which chemical element predominates in the dry matter of the cell? 1) nitrogen 2) carbon 3) hydrogen 4) oxygen
A4. Which phase of meiosis is shown in the picture? 1) Anaphase I 2) Metaphase I 3) Metaphase II 4) Anaphase II
A5. What organisms are chemotrophs? 1) animals 2) plants 3) nitrifying bacteria 4) fungi A6. The formation of a two-layer embryo occurs during the period of 1) cleavage 2) gastrulation 3) organogenesis 4) postembryonic period
A7. The totality of all the genes of an organism is called 1) genetics 2) gene pool 3) genocide 4) genotype A8. In the second generation, with monohybrid crossing and with complete dominance, a splitting of characters is observed in the ratio 1) 3:1 2) 1:2:1 3) 9:3:3:1 4) 1:1
A9. Physical mutagenic factors include 1) ultraviolet radiation 2) nitrous acid 3) viruses 4) benzopyrene
A10. In what part of the eukaryotic cell are ribosomal RNAs synthesized? 1) ribosome 2) rough ER 3) nucleolus 4) Golgi apparatus
A11. What is the term for a section of DNA that codes for one protein? 1) codon 2) anticodon 3) triplet 4) gene
A12. Name the autotrophic organism 1) boletus mushroom 2) amoeba 3) tuberculosis bacillus 4) pine
A13. What is nuclear chromatin made of? 1) karyoplasm 2) strands of RNA 3) fibrous proteins 4) DNA and proteins
A14. At what stage of meiosis does crossing over occur? 1) prophase I 2) interphase 3) prophase II 4) anaphase I
A15. What is formed from the ectoderm during organogenesis? 1) notochord 2) neural tube 3) mesoderm 4) endoderm
A16. A non-cellular form of life is 1) euglena 2) bacteriophage 3) streptococcus 4) ciliates
A17. Protein synthesis into mRNA is called 1) translation 2) transcription 3) reduplication 4) dissimilation
A18. In the light phase of photosynthesis, 1) synthesis of carbohydrates occurs 2) synthesis of chlorophyll 3) absorption of carbon dioxide 4) photolysis of water
A19. Cell division with preservation of the chromosome set is called 1) amitosis 2) meiosis 3) gametogenesis 4) mitosis
A20. Plastic metabolism includes 1) glycolysis 2) aerobic respiration 3) assembly of an mRNA chain on DNA 4) breakdown of starch to glucose
A21. Select the incorrect statement In prokaryotes, the DNA molecule is 1) closed in a ring 2) not associated with proteins 3) contains uracil instead of thymine 4) is singular
A22. Where does the third stage of catabolism occur - complete oxidation or respiration? 1) in the stomach 2) in mitochondria 3) in lysosomes 4) in the cytoplasm
A23. Asexual reproduction includes 1) parthenocarpic formation of fruits in cucumbers 2) parthenogenesis in bees 3) reproduction of tulips by bulbs 4) self-pollination in flowering plants
A24. What organism develops without metamorphosis in the postembryonic period? 1) lizard 2) frog 3) Colorado potato beetle 4) fly
A25. The human immunodeficiency virus affects 1) gonads 2) T-lymphocytes 3) erythrocytes 4) skin and lungs
A26. Cell differentiation begins at the stage 1) blastula 2) neurula 3) zygote 4) gastrula
A27. What are protein monomers? 1) monosaccharides 2) nucleotides 3) amino acids 4) enzymes
A28. In which organelle does the accumulation of substances and the formation of secretory vesicles occur? 1) Golgi apparatus 2) rough ER 3) plastid 4) lysosome
A29. What disease is inherited in a sex-linked manner? 1) deafness 2) diabetes mellitus 3) hemophilia 4) hypertension
A30. Indicate the incorrect statement. The biological significance of meiosis is as follows: 1) the genetic diversity of organisms increases 2) the stability of the species increases when environmental conditions change 3) the possibility of recombination of traits as a result of crossing over appears 4) the probability of combinative variability of organisms decreases.

b) oxygen c) carbon d) hydrogen 2. Which chemical element is simultaneously included in the composition of bone tissue and nucleic acids? a) potassium b) phosphorus c) calcium d) zinc 3. When water freezes, the distance between the molecules: a) decreases b) increases c) does not change 4. Children develop rickets with a lack of: a) manganese and iron b) calcium and phosphorus c) copper and zinc d) sulfur and nitrogen 5. Which element is included in the chlorophyll molecule? a) sodium b) potassium c) magnesium d) chlorine 6. Write down from a number of chemical elements: O, C, H, N, Fe, K, S, Zn, Cu, contained in the cell, those that are: a) the basis organic compounds b) macroelements c) microelements 7. Write out from the proposed series of elements: O, Si, Fe, H, C, N, Al, Mg those that predominate: a) in living nature b) in inanimate nature 8. What is the value water for cell life: a) a medium for chemical elements b) a solvent c) a source of oxygen during photosynthesis Chemical composition of the cell. Organic matter. 1.Which of the named chemical compounds is not a biopolymer? a) protein b) glucose c) DNA d) cellulose 2. From what compounds are hydrocarbons synthesized during photosynthesis? a) from O2 and H2O b) from CO2 and H2 c) from CO2 and H2O d) from CO2 and H2CO3 3. Which product is more advisable to give to a tired marathon runner at a distance to maintain strength? a) A piece of sugar b) a little butter c) a piece of meat d) a little mineral water 4. The ability of camels to tolerate thirst well is explained by the fact that fats: a) retain water in the body b) release water during oxidation c) create a heat-insulating layer that reduces evaporation 5. The largest amount of energy is released during the splitting of one gram: a) C5H12O5 b) C6H10O6 c) C6H12O6 d) C6H12O5 6. In which case is the formula of the glucose molecule written correctly? a) ether b) alcohol c) water d) hydrochloric acid

1.Meaning of chemical
element for the human body
2. What does the lack of this element lead to?
3.What does an excess of this element lead to?
4.What foods contain

All organisms on our planet consist of cells that are similar in chemical composition. In this article we will briefly talk about the chemical composition of the cell, its role in the life of the entire organism, and find out what science studies this issue.

Groups of elements of the chemical composition of the cell

The science that studies the components and structure of a living cell is called cytology.

All elements included in the chemical structure of the body can be divided into three groups:

• macroelements;
• microelements;
• ultramicroelements.

Macroelements include hydrogen, carbon, oxygen and nitrogen. They account for almost 98% of all constituent elements.

Microelements are present in tenths and hundredths of a percent. And a very low content of ultramicroelements - hundredths and thousandths of a percent.

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Translated from Greek, “macro” means big, and “micro” means small.

Scientists have found that there are no special elements that are unique to living organisms. Therefore, both living and inanimate nature consists of the same elements. This proves their relationship.

Despite the quantitative content of a chemical element, the absence or reduction of at least one of them leads to the death of the entire organism. After all, each of them has its own meaning.

The role of the chemical composition of the cell

Macroelements are the basis of biopolymers, namely proteins, carbohydrates, nucleic acids and lipids.

Microelements are part of vital organic substances and participate in metabolic processes. They are constituent components of mineral salts, which are in the form of cations and anions, their ratio determines the alkaline environment. Most often it is slightly alkaline, because the ratio of mineral salts does not change.

Hemoglobin contains iron, chlorophyll - magnesium, proteins - sulfur, nucleic acids - phosphorus, metabolism occurs with a sufficient amount of calcium.

Rice. 2. Cell composition

Some chemical elements are components of inorganic substances, such as water. It plays an important role in the life of both plant and animal cells. Water is a good solvent, because of this all substances inside the body are divided into:

• Hydrophilic - dissolves in water;
• Hydrophobic - do not dissolve in water.

Thanks to the presence of water, the cell becomes elastic and promotes the movement of organic substances in the cytoplasm.

Rice. 3. Cell substances.

Table “Properties of the chemical composition of the cell”

To clearly understand what chemical elements are part of the cell, we included them in the following table:

What have we learned?

Each cell of living nature has its own set of chemical elements. In terms of their composition, objects of living and inanimate nature have similarities, this proves their close relationship. Each cell consists of macroelements, microelements and ultramicroelements, each of which has its own role. The absence of at least one of them leads to illness and even death of the entire organism.

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