What energy is used to carry out photosynthesis? Photosynthesis: what is, definition, phases. Photosynthetic membranes of prokaryotes
Where does photosynthesis occur?
leaves of green plants
Definition
1) Light phase;
2) Dark phase.
Phases of photosynthesis
Light phase
Dark phase
Result
Where does photosynthesis occur?
Well, to answer the question right away, I will say that photosynthesis occurs in leaves of green plants, or rather in their cells. The main role here is played by chloroplates, special cells without which photosynthesis is impossible. I will note that this process, photosynthesis, is, it seems to me, an amazing property of living things.
After all, everyone knows that through photosynthesis, carbon dioxide is absorbed and oxygen is released. Such a phenomenon is simple to understand, and at the same time one of the most complex processes of living organisms, in which a huge number of different particles and molecules take part. So that at the end the oxygen that we all breathe is released.
Well, I’ll try to tell you how we get precious oxygen.
Definition
Photosynthesis is the synthesis of organic substances from inorganic substances using sunlight. In other words, sunlight falling on the leaves provides the necessary energy for the process of photosynthesis. As a result, organic matter is formed from inorganic matter and air oxygen is released.
Photosynthesis occurs in 2 phases:
1) Light phase;
2) Dark phase.
I'll tell you a little about the phases of photosynthesis.
Phases of photosynthesis
Light phase- as the name implies, it occurs in the light, on the surface membrane of green leaf cells (scientifically speaking, on the grann membrane). The main participants here will be chlorophyll, special protein molecules (transporter proteins) and ATP synthetase, which is an energy supplier.
The light phase, like the process of photosynthesis in general, begins with the action of a light quantum on the chlorophyll molecule. As a result of this interaction, chlorophyll comes into an excited state, which is why this very molecule loses an electron, which goes to the outer surface of the membrane. Further, in order to restore the lost electron, the chlorophyll molecule takes it away from the water molecule, which causes its decomposition. We all know that water consists of two hydrogen molecules and one oxygen, and when water decomposes, oxygen enters the atmosphere, and positively charged hydrogen collects on the inner surface of the membrane.
Thus, it turned out that negatively charged electrons are concentrated on one side and positively charged hydrogen protons on the other. From this moment, an ATP synthetase molecule appears, which forms a kind of corridor for the passage of protons to electrons and to reduce this concentration difference, which we discussed below. At this point, the light phase ends and it ends with the formation of the energy molecule ATP and the restoration of the specific NADP*H2 transporter molecule.
In other words, the decomposition of water occurred, due to which oxygen was released and an ATP molecule was formed, which will provide energy for the further course of photosynthesis.
Dark phase– oddly enough, this phase can occur both in the light and in the dark. This phase takes place in special organelles of leaf cells that are actively involved in photosynthesis (plastids). This phase includes several chemical reactions that occur with the help of the same ATP molecule synthesized in the first phase and NADPH. In turn, the main roles here belong to water and carbon dioxide. The dark phase requires a continuous supply of energy. Carbon dioxide comes from the atmosphere, hydrogen was formed in the first phase, and the ATP molecule is responsible for the energy. The main result of the dark phase is carbohydrates, that is, the very organic matter that plants need to live.
Result
This is how the very process of formation of organic matter (carbohydrates) from inorganic matter occurs. As a result, plants receive the products they need to live, and we receive oxygen from the air. I will add that this entire process occurs exclusively in green plants, the cells of which contain chloroplasts (“green cells”).
Helpful0 0 Not very helpful
How is the energy of sunlight converted in the light and dark phases of photosynthesis into the energy of chemical bonds of glucose? Explain your answer.
Answer
In the light phase of photosynthesis, the energy of sunlight is converted into the energy of excited electrons, and then the energy of the excited electrons is converted into the energy of ATP and NADP-H2. In the dark phase of photosynthesis, the energy of ATP and NADP-H2 is converted into the energy of chemical bonds of glucose.
What happens during the light phase of photosynthesis?
Answer
Chlorophyll electrons, excited by light energy, travel along electron transport chains, their energy is stored in ATP and NADP-H2. Photolysis of water occurs and oxygen is released.
What main processes occur during the dark phase of photosynthesis?
Answer
From carbon dioxide obtained from the atmosphere and hydrogen obtained in the light phase, glucose is formed due to the energy of ATP obtained in the light phase.
What is the function of chlorophyll in a plant cell?
Answer
Chlorophyll is involved in the process of photosynthesis: in the light phase, chlorophyll absorbs light, the chlorophyll electron receives light energy, breaks off and goes along the electron transport chain.
What role do the electrons of chlorophyll molecules play in photosynthesis?
Answer
Chlorophyll electrons, excited by sunlight, pass through electron transport chains and give up their energy to the formation of ATP and NADP-H2.
At what stage of photosynthesis is free oxygen formed?
Answer
In the light phase, during photolysis of water.
During which phase of photosynthesis does ATP synthesis occur?
Answer
Pre-light phase.
What substance serves as a source of oxygen during photosynthesis?
Answer
Water (oxygen is released during photolysis of water).
The rate of photosynthesis depends on limiting factors, including light, carbon dioxide concentration, and temperature. Why are these factors limiting for photosynthesis reactions?
Answer
Light is necessary to excite chlorophyll, it supplies energy for the process of photosynthesis. Carbon dioxide is necessary in the dark phase of photosynthesis; glucose is synthesized from it. Temperature changes lead to denaturation of enzymes and photosynthetic reactions slow down.
In what metabolic reactions in plants is carbon dioxide the starting material for the synthesis of carbohydrates?
Answer
In photosynthesis reactions.
The process of photosynthesis occurs intensively in the leaves of plants. Does it occur in ripe and unripe fruits? Explain your answer.
Answer
Photosynthesis occurs in the green parts of plants in the light. Thus, photosynthesis occurs in the skin of green fruits. Photosynthesis does not occur inside the fruit or in the skin of ripe (not green) fruits.
1. Is photosynthesis a process of plastic or energy metabolism? Why?
Photosynthesis refers to the processes of plastic metabolism because accompanied by:
● by the synthesis of complex organic compounds from simpler substances, namely: glucose (C 6 H 12 O 6) is synthesized from inorganic substances (H 2 O and CO 2);
● absorption of light energy.
2. In which organelles of a plant cell does photosynthesis occur? What is a photosystem? What function do photosystems perform?
Photosynthesis occurs in green plastids - chloroplasts.
Photosystems are special pigment-protein complexes located in the membranes of chloroplast thylakoids. There are two types of photosystems – photosystem I and photosystem II. Each of them includes a light-harvesting antenna formed by pigment molecules, a reaction center and electron carriers.
The light-harvesting antenna functions like a funnel: pigment molecules absorb light and transfer all the collected energy to the reaction center, where the trap molecule represented by chlorophyll a is located. Having absorbed energy, the trap molecule goes into an excited state and gives one of its electrons to a special carrier, i.e. oxidizes. Thus, photosystems perform the function of absorbing light and converting light energy into chemical energy.
3. What is the importance of photosynthesis on Earth? Why would the existence of the biosphere be impossible without phototrophic organisms?
Photosynthesis is the only process on the planet during which the light energy of the Sun is converted into the energy of chemical bonds of synthesized organic substances. In this case, the starting compounds for the synthesis of organic substances are energy-poor inorganic substances - carbon dioxide and water.
Organic compounds formed during photosynthesis are transferred as part of food from phototrophic organisms to herbivores, then to carnivores, being a source of energy and building material for the synthesis of other substances, for the formation of new cells and structures. Consequently, thanks to the activity of phototrophs, nutritional needs heterotrophic organisms.
In addition, photosynthesis is a source of molecular oxygen necessary for the respiration of most living organisms. The ozone layer is formed and maintained from oxygen, protecting living organisms on the planet from the harmful effects of short-wave ultraviolet radiation. Thanks to photosynthesis, a relatively constant CO 2 content in the atmosphere is maintained.
4. Characterize the light and dark phases of photosynthesis according to the plan:
1) location of the leak; 2) starting materials; 3) ongoing processes; 4) final products.
What products of the light phase of photosynthesis are used in the dark phase?
Light phase of photosynthesis.
1) Place of leakage: thylakoid membranes.
2) Starting substances: H 2 O, oxidized NADP (NADP +), ADP, H 3 PO 4. Photosynthetic pigments (chlorophylls, etc.) are also necessary for the light phase to occur, but they cannot be called the initial substances of the light phase.
3) Ongoing processes: absorption of light by photosystems, photolysis of water, electron transport to outside thylakoid and the accumulation of protons inside the thylakoid (i.e. the appearance of an electrochemical potential on the thylakoid membrane), ATP synthesis, NADP + reduction.
4) End products: ATP, reduced NADP (NADP H+H +), by-product - molecular oxygen (O 2).
Dark phase of photosynthesis.
1) Place of leakage: chloroplast stroma.
2) Initial substances: CO 2, ATP, reduced NADP (NADP H+H +).
3) Ongoing processes: glucose synthesis (reduction of CO 2 to organic substances), during which ATP hydrolysis and NADP H+H + oxidation occur.
4) End products: glucose (C 6 H 12 O 6), oxidized NADP (NADP +), ADP, H 3 PO 4.
In the dark phase of photosynthesis, light phase products such as NADP H+H + (serves as a source of hydrogen atoms for the synthesis of glucose) and ATP (serves as a source of energy for the synthesis of glucose) are used.
5. Compare photosynthesis and aerobic respiration. Indicate similarities and differences.
Similarities:
● Complex multi-stage processes occurring with the participation of enzymes.
● Photosynthesis and the final (oxygen) stage aerobic respiration occur in double-membrane organelles (chloroplasts and mitochondria, respectively).
● Redox processes, which are accompanied by the transfer of electrons along the electron transport chains of the internal membranes of the corresponding organelles, the appearance of a potential difference on these membranes, the work of ATP synthetase and ATP synthesis.
Differences:
● The process of photosynthesis refers to plastic metabolism because is accompanied by the synthesis of organic substances from inorganic ones and occurs with the absorption of light energy. The process of aerobic respiration refers to energy metabolism, since complex organic substances are broken down and the energy contained in them is released.
● Photosynthesis occurs only in the cells of phototrophic organisms, and aerobic respiration occurs in the cells of most living organisms (including phototrophs).
● Various starting materials and final products. If we consider the summary equations of photosynthesis and aerobic respiration, we can see that the products of photosynthesis are actually the starting materials for aerobic respiration and vice versa.
● NAD and FAD serve as carriers of hydrogen atoms in the process of respiration, and NADP in photosynthesis.
And (or) other significant features.
6. A person consumes approximately 430 g of oxygen per day. An average-sized tree absorbs about 30 kg of carbon dioxide per year. How many trees are needed to provide one person with oxygen?
● In a year, a person consumes: 430 g × 365 = 156,950 g of oxygen.
● Let's calculate the chemical amount of carbon dioxide absorbed per year by one tree:
M (CO 2) = 12 + 16 × 2 = 44 g/mol. n (CO 2) = m: M = 30,000 g: 44 g/mol ≈ 681.8 mol.
● Summary equation of photosynthesis:
6CO 2 + 6H 2 O → C 6 H 12 O 6 + 6O 2
The absorption of 6 moles of carbon dioxide is accompanied by the release of 6 moles of oxygen. This means that, absorbing 681.8 moles of carbon dioxide per year, the tree releases 681.8 moles of oxygen.
● Let’s find the mass of oxygen released by the tree per year:
M (O 2) = 16 × 2 = 32 g/mol. m (O 2) = n × M = 681.8 mol × 32 g/mol = 21,817.6 g
● Let's determine how many trees are needed to provide one person with oxygen. Number of trees = 156,950 g: 21,817.6 ≈ 7.2 trees.
Answer: To provide one person with oxygen, on average, 7.2 trees will be needed (acceptable answers would be “8 trees” or “7 trees”).
7. Researchers divided wheat plants into two groups and grew them in the laboratory under the same conditions, except that the plants in the first group were illuminated with red light, and the plants in the second group were illuminated with green light. In which group of plants did photosynthesis proceed more intensively? What is this connected with?
Photosynthesis proceeded more intensely in plants illuminated with red light. This is due to the fact that the main photosynthetic pigments - chlorophylls - intensively absorb red light (as well as the blue-violet part of the spectrum), and reflect green, which determines the green color of these pigments.
8*. What experiment can be used to prove that the oxygen released during photosynthesis is formed precisely from water molecules, and not from molecules of carbon dioxide or any other substance?
If water labeled with radioactive oxygen is used to carry out photosynthesis (the molecules contain oxygen radionuclide instead of the stable nuclide 16 O), then the radioactive label can be detected in the released molecular oxygen. If you use any other substance containing oxygen radionuclide for photosynthesis, then the released O2 will not contain a radioactive label. In particular, radioactive oxygen contained in the molecules of absorbed carbon dioxide will be found in the synthesized organic substances, but not in the composition of O 2.
*Tasks marked with an asterisk require students to put forward various hypotheses. Therefore, when marking, the teacher should focus not only on the answer given here, but take into account each hypothesis, assessing the biological thinking of students, the logic of their reasoning, the originality of ideas, etc. After this, it is advisable to familiarize students with the answer given.
Photosynthesis is the process of synthesis of organic substances from inorganic ones using light energy. In the vast majority of cases, photosynthesis is carried out by plants using cellular organelles such as chloroplasts containing green pigment chlorophyll.
If plants were not capable of synthesizing organic matter, then almost all other organisms on Earth would have nothing to eat, since animals, fungi and many bacteria cannot synthesize organic substances from inorganic ones. They only absorb ready-made ones, split them into simpler ones, from which they again assemble complex ones, but already characteristic of their body.
This is the case if we talk about photosynthesis and its role very briefly. To understand photosynthesis, we need to say more: what specific inorganic substances are used, how does synthesis occur?
Photosynthesis requires two inorganic substances - carbon dioxide (CO 2) and water (H 2 O). The first is absorbed from the air by above-ground parts of plants mainly through stomata. Water comes from the soil, from where it is delivered to photosynthetic cells by the plant's conducting system. Also, photosynthesis requires the energy of photons (hν), but they cannot be attributed to matter.
In total, photosynthesis produces organic matter and oxygen (O2). Typically, organic matter most often means glucose (C 6 H 12 O 6).
Organic compounds are mostly composed of carbon, hydrogen and oxygen atoms. They are found in carbon dioxide and water. However, during photosynthesis, oxygen is released. Its atoms are taken from water.
Briefly and generally, the equation for the reaction of photosynthesis is usually written as follows:
6CO 2 + 6H 2 O → C 6 H 12 O 6 + 6O 2
But this equation does not reflect the essence of photosynthesis and does not make it understandable. Look, although the equation is balanced, in it the total number of atoms in free oxygen is 12. But we said that they come from water, and there are only 6 of them.
In fact, photosynthesis occurs in two phases. The first one is called light, second - dark. Such names are due to the fact that light is needed only for the light phase, the dark phase is independent of its presence, but this does not mean that it occurs in the dark. The light phase occurs on the membranes of the thylakoids of the chloroplast, and the dark phase occurs in the stroma of the chloroplast.
During the light phase, CO 2 binding does not occur. There is only capture solar energy chlorophyll complexes, storing it in ATP, using energy to reduce NADP to NADP*H 2. The flow of energy from light-excited chlorophyll is provided by electrons transmitted along the electron transport chain of enzymes built into the thylakoid membranes.
The hydrogen for NADP comes from water, which is decomposed by sunlight into oxygen atoms, hydrogen protons and electrons. This process is called photolysis. Oxygen from water is not needed for photosynthesis. Oxygen atoms from two water molecules combine to form molecular oxygen. The reaction equation for the light phase of photosynthesis briefly looks like this:
H 2 O + (ADP+P) + NADP → ATP + NADP*H 2 + ½O 2
Thus, the release of oxygen occurs during the light phase of photosynthesis. The number of ATP molecules synthesized from ADP and phosphoric acid per photolysis of one water molecule can be different: one or two.
So, ATP and NADP*H 2 come from the light phase to the dark phase. Here, the energy of the first and the reducing power of the second are spent on the binding of carbon dioxide. This stage of photosynthesis cannot be explained simply and concisely because it does not proceed in such a way that six CO 2 molecules combine with hydrogen released from NADP*H 2 molecules to form glucose:
6CO 2 + 6NADP*H 2 →C 6 H 12 O 6 + 6NADP
(the reaction occurs with the expenditure of energy ATP, which breaks down into ADP and phosphoric acid).
The given reaction is just a simplification to make it easier to understand. In fact, carbon dioxide molecules bind one at a time, joining the already prepared five-carbon organic substance. An unstable six-carbon organic substance is formed, which breaks down into three-carbon carbohydrate molecules. Some of these molecules are used to resynthesize the original five-carbon substance to bind CO 2 . This resynthesis is ensured Calvin cycle. A minority of carbohydrate molecules containing three carbon atoms exit the cycle. All other organic substances (carbohydrates, fats, proteins) are synthesized from them and other substances.
That is, in fact, three-carbon sugars, not glucose, come out of the dark phase of photosynthesis.
Photosynthesis is the process that results in the formation and release of oxygen by plant cells and some types of bacteria.
Basic concept
Photosynthesis is nothing more than a chain of unique physical and chemical reactions. What does it consist of? Green plants, as well as some bacteria, absorb sunlight and convert them into electromagnetic energy. The end result of photosynthesis is the energy of chemical bonds of various organic compounds.
In a plant exposed to sunlight, redox reactions occur in a certain sequence. Water and hydrogen, which are donor-reducing agents, move in the form of electrons to the acceptor-oxidizing agent (carbon dioxide and acetate). As a result, reduced carbohydrate compounds are formed, as well as oxygen, which is released by plants.
History of the study of photosynthesis
For many millennia, man was convinced that a plant’s nutrition occurs through its root system through the soil. At the beginning of the sixteenth century, the Dutch naturalist Jan Van Helmont conducted an experiment with growing a plant in a pot. After weighing the soil before planting and after the plant had reached a certain size, he concluded that all representatives of the flora received nutrients mainly from water. Scientists adhered to this theory for the next two centuries.
An unexpected but correct assumption about plant nutrition was made in 1771 by the English chemist Joseph Priestley. The experiments he carried out convincingly proved that plants are capable of purifying air that was previously unsuitable for human breathing. Somewhat later, it was concluded that these processes are impossible without the participation of sunlight. Scientists have found that green plant leaves do more than simply convert the carbon dioxide they receive into oxygen. Without this process their life is impossible. Together with water and mineral salts, carbon dioxide serves as food for plants. This is the main significance of photosynthesis for all representatives of the flora.
The role of oxygen for life on Earth
The experiments carried out by the English chemist Priestley helped humanity explain why the air on our planet remains breathable. After all, life is maintained despite the existence of a huge number of living organisms and the burning of countless fires.
The emergence of life on Earth billions of years ago was simply impossible. The atmosphere of our planet did not contain free oxygen. Everything changed with the advent of plants. All the oxygen in the atmosphere today is the result of photosynthesis occurring in green leaves. This process changed the appearance of the Earth and gave impetus to the development of life. This invaluable significance of photosynthesis was fully realized by humanity only at the end of the 18th century.
It is not an exaggeration to say that the very existence of people on our planet depends on the state of the plant world. The importance of photosynthesis lies in its leading role for the occurrence of various biosphere processes. On a global scale, this amazing physicochemical reaction leads to the formation of organic substances from inorganic ones.
Classification of photosynthesis processes
Three important reactions occur in a green leaf. They represent photosynthesis. The table in which these reactions are recorded is used in the study of biology. Its lines include:
Photosynthesis;
- gas exchange;
- evaporation of water.
Those physicochemical reactions that occur in the plant during daylight allow green leaves to release carbon dioxide and oxygen. In the dark - only the first of these two components.
The synthesis of chlorophyll in some plants occurs even in low and diffuse lighting.
Main stages
There are two phases of photosynthesis, which are closely related to each other. At the first stage, the energy of light rays is converted into high-energy compounds ATP and universal reducing agents NADPH. These two elements are the primary products of photosynthesis.
At the second (dark) stage, the resulting ATP and NADPH are used to fix carbon dioxide until it is reduced to carbohydrates. The two phases of photosynthesis differ not only in time. They also occur in different spaces. For anyone studying the topic “photosynthesis” in biology, a table with a precise indication of the characteristics of the two phases will help in a more accurate understanding of the process.
Mechanism of oxygen production
After plants absorb carbon dioxide, nutrients are synthesized. This process is carried out in green pigments called chlorophylls, under the influence of sun rays. The main components of this amazing reaction are:
Light;
- chloroplasts;
- water;
- carbon dioxide;
- temperature.
Sequence of photosynthesis
Plants produce oxygen in stages. The main stages of photosynthesis are as follows:
Absorption of light by chlorophylls;
- division of water obtained from soil into oxygen and hydrogen by chloroplasts (intracellular organelles of green pigment);
- movement of one part of oxygen into the atmosphere, and the other for the respiratory process of plants;
- formation of sugar molecules in protein granules (pyrenoids) of plants;
- production of starches, vitamins, fats, etc. as a result of mixing sugar with nitrogen.
Despite the fact that photosynthesis requires sunlight, this reaction can also occur under artificial light.
The role of flora for the Earth
The basic processes occurring in a green leaf have already been studied quite fully by the science of biology. The importance of photosynthesis for the biosphere is enormous. This is the only reaction that leads to an increase in the amount of free energy.
During the process of photosynthesis, one hundred and fifty billion tons of organic substances are formed every year. In addition, during this period, plants release almost 200 million tons of oxygen. In this regard, it can be argued that the role of photosynthesis is enormous for all of humanity, since this process serves as the main source of energy on Earth.
In the process of a unique physicochemical reaction, the cycle of carbon, oxygen, and many other elements occurs. This implies another important significance of photosynthesis in nature. This reaction maintains a certain composition of the atmosphere at which life on Earth is possible.
A process occurring in plants limits the amount of carbon dioxide, preventing it from accumulating in increased concentrations. This is also an important role for photosynthesis. On Earth thanks green plants the so-called greenhouse effect is not created. Flora reliably protects our planet from overheating.
Flora as the basis of nutrition
The role of photosynthesis for forest and Agriculture. Vegetable world is a nutritional base for all heterotrophic organisms. However, the significance of photosynthesis lies not only in the absorption of carbon dioxide by green leaves and the production of such a finished product of a unique reaction as sugar. Plants are capable of converting nitrogen and sulfur compounds into substances that make up their bodies.
How does this happen? What is the importance of photosynthesis in plant life? This process is carried out through the production of nitrate ions by the plant. These elements are found in soil water. They enter the plant through the root system. The cells of a green organism process nitrate ions into amino acids, which make up protein chains. The process of photosynthesis also produces fat components. They are important reserve substances for plants. Thus, the seeds of many fruits contain nutritious oil. This product is also important for humans, as it is used in the food and agricultural industries.
The role of photosynthesis in crop production
In the world practice of agricultural enterprises, the results of studying the basic patterns of plant development and growth are widely used. As you know, the basis for crop formation is photosynthesis. Its intensity, in turn, depends on the water regime of crops, as well as on their mineral nutrition. How does a person achieve an increase in crop density and leaf size so that the plant makes maximum use of the sun's energy and takes carbon dioxide from the atmosphere? To achieve this, the conditions for mineral nutrition and water supply to agricultural crops are optimized.
It has been scientifically proven that yield depends on the area of green leaves, as well as on the intensity and duration of the processes occurring in them. But at the same time, an increase in crop density leads to shading of the leaves. Sunlight cannot penetrate to them, and due to the deterioration of ventilation of air masses, carbon dioxide enters in small volumes. As a result, the activity of the photosynthesis process decreases and plant productivity decreases.
The role of photosynthesis for the biosphere
According to the most rough estimates, only autotrophic plants living in the waters of the World Ocean annually convert from 20 to 155 billion tons of carbon into organic matter. And this despite the fact that the energy of solar rays is used by them only by 0.11%. As for terrestrial plants, they annually absorb from 16 to 24 billion tons of carbon. All these data convincingly indicate how important photosynthesis is in nature. Only as a result of this reaction is the atmosphere replenished with the molecular oxygen necessary for life, which is necessary for combustion, respiration and various industrial activities. Some scientists believe that when carbon dioxide levels in the atmosphere increase, the rate of photosynthesis increases. At the same time, the atmosphere is replenished with missing oxygen.
The cosmic role of photosynthesis
Green plants are intermediaries between our planet and the Sun. They capture the energy of the heavenly body and ensure the existence of life on our planet.
Photosynthesis is a process that can be discussed on a cosmic scale, since it once contributed to the transformation of the image of our planet. Thanks to the reaction taking place in green leaves, the energy of the sun's rays is not dissipated in space. It turns into chemical energy of newly formed organic substances.
Human society needs the products of photosynthesis not only for food, but also for economic activities.
However, not only those rays of the sun that fall on our Earth at the present time are important to humanity. Those products of photosynthesis that were obtained millions of years ago are extremely necessary for life and production activities. They are found in the bowels of the planet in the form of layers of coal, combustible gas and oil, and peat deposits.
Loading...