How do living beings differ from objects of inanimate nature: comparisons, similarities and differences. How to show the connection between living and inanimate nature? Why are humans classified as living nature? What indicates the unity of living and nonliving

Chemical elements of the cell

There is not a single chemical element in living organisms that would not be found in bodies of inanimate nature (which indicates the commonality of living and inanimate nature).
Different cells include almost the same chemical elements (which proves the unity of living nature); and at the same time, even the cells of one multicellular organism, performing different functions, can differ significantly from each other in chemical composition.
Of the more than 115 elements currently known, about 80 have been found in the cell.

All elements, according to their content in living organisms, are divided into three groups:

1. macronutrients- the content of which exceeds 0.001% of body weight.
   98% of the mass of any cell comes from four elements (sometimes called organogens): - oxygen (O) - 75%, carbon (C) - 15%, hydrogen (H) - 8%, nitrogen (N) - 3%. These elements form the basis of organic compounds (and oxygen and hydrogen, in addition, are part of the water, which is also contained in the cell). About 2% of the cell mass accounts for another eight macronutrients: magnesium (Mg), sodium (Na), calcium (Ca), iron (Fe), potassium (K), phosphorus (P), chlorine (Cl), sulfur (S);
2. The remaining chemical elements are contained in the cell in very small quantities: microelements- those whose share is from 0.000001% to 0.001% - boron (B), nickel (Ni), cobalt (Co), copper (Cu), molybdenum (Mb), zinc (Zn), etc.;
3. ultramicroelements- the content of which does not exceed 0.000001% - uranium (U), radium (Ra), gold (Au), mercury (Hg), lead (Pb), cesium (Cs), selenium (Se), etc.

Living organisms are capable of accumulating certain chemical elements. For example, some algae accumulate iodine, buttercups - lithium, duckweed - radium, etc.

Cell chemicals

Elements in the form of atoms are part of molecules inorganic And organic cell connections.

TO inorganic compounds include water and mineral salts.

Organic compounds are characteristic only of living organisms, while inorganic ones also exist in inanimate nature.

TO organic compounds These include carbon compounds with a molecular weight ranging from 100 to several hundred thousand.
Carbon is the chemical basis of life. It can interact with many atoms and their groups, forming chains and rings that make up the skeleton of organic molecules of different chemical composition, structure, length and shape. They form complex chemical compounds that differ in structure and function. These organic compounds that make up the cells of living organisms are called biological polymers, or biopolymers. They make up more than 97% of the dry matter of the cell.

What is living and inanimate nature: signs, description, examples

Sometimes children drive their parents into a blind corner by asking tricky questions. Sometimes you don’t even know how to answer them, and sometimes you just can’t find the right words. After all, children need not only to be explained correctly, but also to speak in a language accessible to them.

The topic of living and inanimate nature begins to interest children even before the start of school life, and it is of great importance in correctly perceiving the world around them. Therefore, you need to thoroughly understand the topic of nature and understand why they are distinguished and what it is - living and inanimate nature.

What is wildlife: signs, description, examples

Let's first figure out (or just remember) what nature is as a whole. There are a lot of living organisms and inanimate objects around us. Everything that can appear and develop without human participation is called nature. That is, for example, forests, mountains, fields, stones and stars belong to our nature. But cars, houses, airplanes and other buildings (as well as equipment) have nothing to do even with the inanimate area of ​​nature. This is what man himself created.

By what criteria are living nature identified?

• In any case, a living organism will grow and develop. That is, he will definitely go through a life cycle from birth to death (yes, as sad as that sounds). Let's look at an example.
  • Let's take any animal (let it be a deer). He is born, learns to walk after a certain time, and grows. Then, as adults, their own children appear, the same fawns. And in the final stage, the deer grows old and leaves this world.
  • Now let's take a seed (any seed, let it be a sunflower seed). If you plant it in the ground (by the way, this process is also thought out by nature). After a certain time, a small process appears, which gradually grows and increases in size. It begins to bloom, its seeds appear (which then fall to the ground and repeat a new life cycle). Finally, the sunflower dries out and dies.
• Reproduction, as an integral and important component of any living object. We have given some examples above that show that all living organisms reproduce. That is, every animal has babies, every tree sends out shoots from which new trees grow. And flowers and various plants scatter their seeds so that they germinate in the ground and new and young plants emerge from them.
• Nutrition is an integral part of our life. All those who feed on any kind of food (this could be other animals, plants or water) belong to living nature. To maintain life and development, living organisms simply need food. After all, from it we find the strength to develop and grow.

• Breath– another important component of living nature. Yes, some animals or small organisms perform this function in the same way as humans. We inhale oxygen using our lungs. And we exhale carbon dioxide. Fish and other inhabitants that live underwater have gills for these purposes. But, for example, trees and grass breathe through their leaves. By the way, they do not need oxygen, but, on the contrary, carbon dioxide. Moreover, through special tiny cells (they also carry out important metabolic processes), oxygen is released, which is necessary for animals and humans.
• Movement- that's life! There is such a motto, and it completely characterizes the living world. Try sitting or lying down all day. Your arms and legs will just hurt. Muscles need to work and develop. By the way, children often have questions about how trees or flowers move in a flower bed. After all, they have no legs and do not move around the city. But notice that the plants turn to follow the sun.
  • Try an experiment! Even at home, on the windowsill, watch the flower. If you turn him in the other direction from the window, then after a while he will look out the window again. The plants just make their movements very slowly and smoothly.
• And the last, final stage is dying. Yes, we touched on in the first point that everyone completes their life cycle. By the way, there is also a fine line in this matter.
  • For example, a tree that grows belongs to living nature. But a plant that has already been cut down will not breathe, move or reproduce. This means that automatically it will already relate to inanimate nature. By the way, the same applies to a plucked flower.

Now let’s delve a little deeper into the topic of what other signs of living nature there are:

We have specified important and mandatory conditions. Now let's add some scientific facts. Let's just say, in order for your child to shine even more with intelligence and intelligence. After all, do not forget that information in terms of study is never superfluous.

• We mentioned that wildlife must move, breathe, eat, and go through a life cycle. But I would like to add one small nuance. These are waste products and excrement. Excretion– This is the body’s ability to get rid of toxins and waste. Simply put, all living organisms go to the toilet. This is simply a necessary chain so as not to poison our cells. Trees, for example, shed their leaves and change their bark.
• By the way, about cells. All living organisms are made of cells! There are simple creatures that consist of only one or a few cells (these are so-called bacteria). But more on that a little later.
  • Many cells are grouped into tissue. And they, in turn, form a whole organ. Organs, or rather their composition (that is, a set, a group) make the finished organism. By the way, all living beings that consist of organs belong to the class of higher representatives. And they are very complex organisms.

IMPORTANT: To make this topic clearer to your child, make a person or other living creature from a construction set. Let him imagine that each part is a cell.

• One cannot fail to note the energy of the Sun and Earth. All living beings simply need sunlight and use the gifts of the earth. For example, minerals. The most accessible and understandable are salt or coal, which are extracted from its soil.
• Each of us has our own behavioral habits. This is called environmental response. Behavior is a very complex set of reactions. By the way, they differ from each other for every living creature.
• We can all adapt to any changes. A person, for example, came up with the idea of ​​​​using an umbrella during the rainy season, while other animals simply hide under a canopy or tree.

What types of living beings does biology distinguish?

• Microorganisms. These are the most ancient representatives of living nature. They can develop where there is water or moisture. Even such tiny representatives can grow, reproduce and go through a whole complex of life cycles. By the way, they can feed on water and other nutrients. These usually include bacteria, viruses and fungi (but not the ones you and I eat).
• Plants or flora(speaking scientifically). The diversity is simply enormous - grass, flowers, trees, and even single-celled algae (and more). Give your child complete information about why they belong to the living world.
  • After all, they breathe. Yes, we remember that plants produce oxygen and absorb (or absorb) carbon dioxide.
  • They are moving. They turn after the sun, curl up leaves or drop them.
  • They are feeding. Yes, some do it through the soil (for example, flowers), get nutrients from water, or do it all from two resources.
  • They grow and multiply. We will not repeat ourselves, since we have already given examples of such an explanation above.
• This is simply a huge complex that includes wild or domestic animals, insects, birds, fish, amphibians or mammals. They can breathe, eat, grow, develop and reproduce. Moreover, they have one more feature - the ability to adapt to environmental conditions.

• Human. It stands at the very top of living nature, since it has all the above characteristics. Therefore, we will not repeat them.

What is inanimate nature: signs, description, examples

As you may have already guessed, inanimate nature cannot breathe, grow, eat, or reproduce. Although there are some nuances in these issues. For example, mountains can grow. And huge plates of the earth can move. But we will talk about this in more detail later.

Therefore, let's highlight the main signs of inanimate nature.

• They do not go through a life cycle. That is, they do not grow or develop. Yes, mountains can “grow” (increase in volume) or crystals of salt or other minerals can increase in size. But this is not due to cell proliferation. And because “newly arrived” parts appear. Also, one cannot fail to note the dust and other layers (this is what is directly related to the mountains).
• They don't eat. Do the mountains, stone or our planet not eat? No, inanimate nature does not need to receive additional energy (for example, the Sun and the same Earth) or any nutrients. They simply don’t need it!
• They don't move. If you kick a person, he will begin to fight back (the reaction to the environment will also be involved here). If you push the plant, it will either stay in place (since it has a root) or lose its leaves (which will then grow back). But if you kick a stone, it will simply move a certain distance. And he will continue to lie there immobilized.
  • The water in the river moves, but not because he is alive. The wind, the slope of the terrain play a role, and don’t forget about such a tiny detail as particles. Humans, for example, are made up of cells, but water (and other non-living elements) are made up of tiny particles. And in those places where the connection between particles is the least, they try to occupy the lowest place. As they move, they form a current.
• Of course, one cannot help but highlight them sustainability. Yes, the question may arise in your head that sand and earth are in a free-flowing state (you can make Easter cakes from them). But they can easily withstand the weight of not only one person, but a whole billion (even several). And there’s no need to even explain about the stone.

• Weak variability- another sign of inanimate nature. A stone can change its shape, for example, under the influence of a current. But this will take not even a month or two, but several years.
• And we also need to note the point lack of reproduction. Inanimate nature does not give birth to young, it does not have offspring, or it does not develop additional shoots. The thing is that their life cycle does not end. Take even our planet – it is already many years old. And the Sun, stars or mountains. All of them have also been in their place in an unchanged state for many, many years.

IMPORTANT: The only change in nature is the transition from one state to another. That is, for example, a stone can become dust over time. And the most striking example is water. It can evaporate, then accumulate in clouds and fall as precipitation (rain or snow). It can also become ice, that is, take on a solid form. We remind you that there are three states - gaseous, liquid and solid forms.

What types of inanimate nature exist?

Already in the elementary grades, a child should have a basic understanding not only of living nature, but also of inanimate elements. To make them easier to perceive, we need to immediately distinguish three groups. Moreover, in the future in geography lessons this will only be a plus.

• Lithosphere. We all live in such a huge house as the Earth (by the way, this is the only planet in space where there is life). It does not consist only of earth, sand and vegetation. This is a relatively small (although its layer is at least 10 km) surface layer.
  • And below it there are still layers of the mantle (they are in a molten state and tens of times thicker than the topmost layer), while inside the planet there is a core (it consists of molten metals).
  • And let’s not forget about such an important condition that our earth’s crust consists of puzzles. Yes, they are called lithospheric plates. But for a more understandable perception, they can be placed in the form of pieces of a picture. So they divide the globe into continents and oceans.
    • Where they descend, bodies of water (seas, rivers and oceans) are formed.
    • In places of elevation, surfaces of the earth and even mountains are formed (they appear as a result of one plate overlapping another).
  • Hydrosphere. Naturally, this is the water part of the Earth. By the way, it occupies almost 70% of the entire surface. These are rivers, lakes, streams, seas and oceans.
  • Atmosphere. This is, in other words, air. It has several layers and has two main components - nitrogen (occupies as much as 78%) and oxygen (only 21%).

IMPORTANT: We need oxygen to maintain life. But nitrogen, diluting it, prevents unnecessary inhalation of oxygen. So these components are very important to us and they keep each other in balance.

By the way, it still needs to be highlighted separately. After all, without it there would be nothing alive. Yes, in principle, there would simply be darkness. He gives us warmth, light and energy.

How do living beings differ from objects of inanimate nature: comparisons, features, similarities and differences

We have already given a complete concept of each aspect, highlighting the main differences between living and inanimate nature. That is, they showed their main characteristics. Moreover, they provided it in expanded form, so we will not repeat it.

I would just like to add what similarities there are between living and inanimate nature:

• We are all subject to the same physical laws. Throw down a stone or lizard. They will fall down. The only thing is that the bird will fly into the sky. But this is due to the presence of wings. Underwater it will still go to the bottom.
• All chemical reactions have the same effect on living and inanimate nature. A lightning strike leaves a similar mark. Or an even simpler example is the appearance of salt deposits. Either on a stone or on a person, white stripes will remain from the drying of sea water.
• Of course, we don’t forget about the laws of mechanics. Again, everyone is exposed to them equally, without exception. For example, under the influence of a strong wind, we begin to walk faster (if we follow it), and clouds begin to float faster across the sky.

• We all have some changes. It’s just that a person or any other animal grows and changes shape. The stone also wears down, the cloud changes shape and color depending on the content of the number of water droplets (that is, moisture).
• By the way, color. Some animals have or can become the same color as inanimate objects.
• Form. Pay attention to the similarity of a shell or lichen to a stone, or the structure of graphite to a honeycomb. But don’t snowflakes with starfish, for example, evoke a certain symmetry in their shapes?
• And, of course, we need light and energy from the Sun.

How to show the connection between living and inanimate nature? Invisible threads between living and inanimate nature: description

We gave not only the differences between living and inanimate nature, but also showed the common features between them. But we also need to highlight the fact that in nature everything is interconnected.

• For example, the simplest thing is water. It is necessary for all living representatives. Be it a person, a lion, a squirrel or a flower. The only difference is that plants receive moisture through the root, and animals drink it.
• Sun. It belongs to inanimate nature, but it is simply necessary for green plants to produce oxygen. Living beings need it in order to see and develop normally. By the way, the stars and the Moon perform a similar function at night, for example, to illuminate the path.
• Some animals live in burrows that they dig in the ground. And others, for example, ducks, live in the reeds. Moss grows on stone.
• Some minerals provide nutrition to many animals and humans. Let’s even take the most banal salt. Coal helps keep you warm, and it is mined from the depths of the earth. By the way, this also includes the gas that enters our burners and pipes.

• But animals play an important role. For example, fallen leaves, rotting, nourish the soil. Even some animal and human waste contributes to its enrichment. But this does not mean household waste; it does not rot.
• Plants provide shelter for most animals, and they, in turn, pollinate the plants, scatter seeds and drive away pests. For example, a tree or stone serves as a home for a person (if it is built).
• These are not all examples. Each chain of our life is closely interconnected with other aspects of nature. By the way, I would also like to highlight oxygen, without which not a single representative of living nature would exist.

What indicates the commonality of living and inanimate nature?

To do this, you need to remember the physics course. All living and nonliving objects are made of particles. Or rather, from atoms. But this is a slightly different, more complex science. And I would also like to incorporate knowledge from chemistry. All representatives of nature have the same chemical composition. No, they are all different in their own way.

• But in any living representative there is the same element that is also found in inanimate nature. For example, even water. It is found in all plants, animals, humans and even microorganisms.

The role of soil in the relationship between living and inanimate nature: description

The role of water and oxygen is simply enormous for living nature. But the soil itself simply cannot be overestimated. Therefore, let's start right away with the most important thing.

• The soil is home to most representatives of the animal world. Some live in it, while others simply build houses. Plants also “live” in the soil, because they cannot grow any other way.
• It is the most nutritious. Yes, no one can compare with her. After all, it contains all the necessary minerals and elements. Moreover, sometimes the connection can also have indirect contact.

For example, soil nourishes plants and, together with water, promotes their growth. And they already become food for other animals. By the way, some animals are food for representatives of the higher chain.

IMPORTANT: We have already mentioned this, that animals and plants also enrich it after their death. And the chain begins again, the resulting substances become food for microorganisms and other plants.

• For people, for example, it also serves as the basis for the extraction of all minerals and minerals. Even the same coal. And also oil, gas or metal ores.

Factors of inanimate nature affecting living organisms: description

Yes, all factors of inanimate nature influence living organisms. And to a direct extent. You can find a whole lot of them, but let’s highlight the most basic and important ones.

1. Light and warmth. Refers to one point, since living organisms receive it from the Sun. Yes, its role is also difficult to overestimate, because without the Sun there would simply be no life on Earth.
   • Without light, many organisms would simply die. Light enables many chemical processes in organisms. For example, plants can only produce oxygen when exposed to sunlight. Yes, and you and I would look completely different.
   • The temperature in each climate zone is different. For example, at the equator (in the middle of the globe) it is maximum. The vegetation there is completely different and, for example, the skin color of the inhabitants is darker. And the animals there have different characteristics.
   • In the north, on the contrary, people with paler skin live. And you are unlikely to see a giraffe or crocodile in the Arctic. Plants also change with the degree of temperature change. The color and shape of the leaves changes.
   • And cold, in general, can be destructive for many living beings. At very low temperatures, neither a person, nor an animal, nor a plant, nor even a bacterium will survive for a long time.
2. Humidity. It is also important for all life on the planet. Without it, both animals and plants will die in the same way. If humidity drops below the required limit, vital activity will begin to decrease.
   • By the way, in hot climates, water vapor is better preserved. Therefore, frequent precipitation in the form of rain is observed. For example, in the tropics they can be in huge numbers and last for several days.
   • In cold regions, approximately 40-45% of moisture is lost to the formation of dew or snow. We can conclude that the colder the area, the less often it rains. But in hot climates you rarely see snowfall.
3. In the north, the ground is covered with a layer of snow. Therefore, she will not be so rich. In hot countries, sand is more common. The most fertile soil is considered to be chernozem (that is, black soil).
   • By the way, the shape of the soil is also important. In the mountains, again, there will be other plants and animals that have adapted to live on the slopes. But in low areas, near swamps, their own rules reign.

Why are humans classified as living nature?

Man is not just a living nature, he is at the top of the entire chain! We talked at the very beginning about the signs. So we draw conclusions about this. A person breathes, eats, grows and develops. Everyone has their own children, and in the final stage we leave this world.

• Moreover, humans know how to adapt to climate change and other environmental changes.
• We all have our own reaction to what is happening. Yes, when we are pushed, we do not fly aside, but fight back.
• We make maximum use of the resources not only of the earth, but also of the ocean and space.
• Man uses heat, light and energy from the sun.
• Man has all the features of living nature; he has a mind and a soul. Moreover, he makes the most of this opportunity.

For example, animals cannot build their own house. And the person even makes a whole work of art. And this is just a small example of his activities. We make the most of plants, trees and other animals. Even if we take the lion - the king of beasts. His man can easily defeat (yes, for these purposes he uses inventions such as a dagger or a pistol).

Video: Living and inanimate nature: objects and phenomena

Help please Signs of living bodies Non-living bodies Non-living bodies

and inanimate nature

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Give three examples: bodies of living and inanimate nature, when describing which use the same characteristics: mass, shape, size, color.

1. The term ecology was introduced by 2. the founder of biogeography 3. The branch of biology that studies the relationships of living organisms with each other and with inanimate nature.4. V

as an independent science, ecology began to develop 5. the direction of movement of natural selection dictates 6. Environmental factors that affect the body 7. A group of environmental factors determined by the influence of living organisms 8. A group of environmental factors determined by the influence of living organisms 9. A group of environmental factors caused by the influence of inanimate nature 10. A factor of inanimate nature that gives impetus to seasonal changes in the life of plants and animals. 11. the ability of living organisms to determine their biological rhythms depending on the length of the day 12. The most significant factor for survival 13. Light, the chemical composition of air, water and soil, atmospheric pressure and temperature are among the factors 14. construction of railways, plowing of land, creation of mines refers to 15. Predation or symbiosis refers to factors 16. long-living plants 17. short-dwelling plants 18. tundra plants include 19. Semi-desert, steppe and desert plants include 20. Characteristic indicator of a population. 21. The set of all types of living organisms that inhabit a certain territory and interact with each other 22. The richest ecosystem in species diversity on our planet 23. an ecological group of living organisms that create organic substances 24. an ecological group of living organisms that consume ready-made organic substances, but do not carry out mineralization 25. an ecological group of living organisms that consume ready-made organic substances and contribute to their complete transformation into mineral substances 26. useful energy moves to the next trophic (nutritional) level 27. consumers of the first order 28. consumers of the second or third order 29. a measure of the sensitivity of communities of living organisms to changes in certain conditions 30. the ability of communities (ecosystems or biogeocenoses) to maintain their constancy and resist changes in environmental conditions 31. low ability for self-regulation, species diversity, the use of additional energy sources and high productivity are characteristic of 32. artificial biocenosis with the highest metabolic rate per unit area. involving the circulation of new materials and the release of a large amount of non-recyclable waste are characteristic of 33. arable land is occupied by 34. cities are occupied by 35. the shell of the planet populated by living organisms 36. the author of the study of the biosphere 37. the upper limit of the beosphere 38. the boundary of the biosphere in the depths of the ocean. 39 the lower boundary of the biosphere in the lithosphere. 40. an international non-governmental organization created in 1971, carrying out the most effective actions in defense of nature.

1. What is a chemical element?
2. What chemical organic substances do you know?
3. Which substances are called simple and which complex?

The cells of all living organisms consist of the same chemical elements. These same elements are also included in the composition of inanimate objects. The similarity of composition indicates the commonality of living and inanimate nature.

Cells contain the most chemical elements such as carbon, hydrogen, oxygen and nitrogen. Together they make up up to 98% of the cell's mass.

About 2% of the cell's mass is made up of the following eight elements: potassium, sodium, calcium, chlorine, magnesium, iron, phosphorus and sulfur. The remaining chemical elements are contained in cells in very small quantities.

Chemical elements combine with each other to form inorganic and organic substances.

Inorganic substances of the cell- this is water and mineral salts. Most of all the cell contains water (from 40 to 95% of its total mass). Water gives the cell elasticity, determines its shape, and participates in metabolism.

The higher the metabolic rate in a particular cell, the more water it contains.

Approximately 1-1.5% of the total cell mass is made up of mineral salts, in particular calcium, potassium, phosphorus, etc. salts. These inorganic substances are used for the synthesis of organic molecules (proteins, nucleic acids, etc.) - With a lack of minerals, the most important processes are disrupted cell life.

Organic matter- complex carbon-containing compounds. They are part of all living organisms. Initially, it was believed that organic substances are formed only by living organisms, which is why they were called organic. These include carbohydrates, proteins, fats, nucleic acids and other substances.

Carbohydrates- an important group of organic substances, as a result of the breakdown of which cells receive the energy necessary for their life. Carbohydrates are part of cell membranes, giving them strength. Storage substances in cells are starch and sugars, they also belong to carbohydrates.

Squirrels play a vital role in cell life. They are part of various cellular structures, regulate vital processes and can also be stored in cells.

Fats deposited in cells. When fats are broken down, the energy needed by living organisms is released.

Nucleic acids play a leading role in preserving hereditary information and transmitting it to descendants.

A cell is a miniature natural laboratory in which various chemical compounds are synthesized and undergo changes. The similarity of the chemical composition of cells of different organisms proves the unity of living nature.

Answer the questions

1. What chemical elements are most abundant in a cell?
2. What role does water play in the cell?
3. What role do mineral salts play in the cell?
4. What substances are classified as organic?
5. What is the importance of organic substances in a cell?
6. What indicates the commonality of living and inanimate nature?

New concepts

Inorganic substances. Organic substances. Carbohydrates. Squirrels. Fats. Nucleic acids.

Think!

Why is a cell compared to a miniature natural laboratory?

My laboratory

In 1933, as a result of many years of research, scientists learned to obtain vitamin C (ascorbic acid) from glucose. Before this, vitamin C was a scarce and expensive product.

To detect organic matter in plants, perform the following experiments.

Take wheat grains, grind them into flour in a mortar, add a few drops of water and prepare a piece of dough. Wrap the dough in cheesecloth, place the bag in a glass of water and rinse it. A cloudy suspension forms. Pour part of the cloudy liquid from the glass into a test tube and drop 2-3 drops of iodine solution into it. The liquid will turn blue. Take starch on the tip of tweezers and stir it in a test tube with water. Place 2-3 drops of iodine solution into this test tube. Water with starch will also turn blue. This means that wheat grains contain starch, which turns blue with iodine. Place a drop of iodine solution on a cut potato tuber. You will see that the potato tuber also contains starch.

Examine the remaining dough on the cheesecloth. You will see a sticky mass, it is called gluten or vegetable protein.

Take a few sunflower seeds, peel them and crush them on a piece of paper, you will see greasy spots. This confirms the presence of a significant amount of fat in sunflower seeds.

In 1802, scientists discovered a new organic substance and called it grape sugar or glucose (from the Greek glycis - sweet). Glucose is found in ripe fruits and berries and is part of human blood. It is necessary for living cells to form more complex carbohydrates: starch, glycogen, cellulose.

Starch, a widespread storage nutrient, consists of glucose units connected to each other. In the form of starch grains, it accumulates in the cells of potato tubers, pea seeds, oat grains, and corn (Fig. 8). Man uses starch by extracting it from potatoes and corn.

Rice. 8. Potato starch grains in cages

Glycogen has a structure similar to starch. It serves as a storage substance in the bodies of some animals and humans.

In plant cells, thousands of glucose units connected to each other form cellulose, or fiber (from the Latin cellulose - cell). It gives elasticity and strength to the walls of plant cells. Cellulose can be broken down by many bacteria, fungi, and single-celled microorganisms, so they play a major role in the decomposition of plant residues.

Almost pure cellulose is cotton wool and poplar fluff. Based on purified cellulose, transparent cellophane film is made, as well as artificial fiber - viscose (from the Latin viscosus - viscous).

Almost 40% of dry wood consists of cellulose. Cellulose obtained from wood is widely used by humans in the production of paper (from the Persian bombak - cotton). Paper was invented in ancient China, but then it was made from cotton and bamboo fibers. Only in the 18th century. It was discovered that wood could be a convenient starting material for paper production. The first factories for processing wood into pulp were built only in the 19th century.