Define the terms metabolism. What is "metabolism" (metabolism) and why is it important to define it? Basic exchange - what is it
A prerequisite The existence of any living organism is the constant intake and excretion of the end products of decay.
What is metabolism in biology
Metabolism, or metabolism, is a special set of chemical reactions that take place in any living organism to maintain its activity and life. Such reactions give the body the opportunity to develop, grow and multiply, while maintaining its structure and responding to environmental stimuli.
Metabolism is usually divided into two stages: catabolism and anabolism. At the first stage, all complex substances are broken down and become simpler. On the second, along with energy costs, nucleic acids, lipids and proteins are synthesized.
The most important role in the metabolic process is played by enzymes that are active. They are able to reduce the activation energy of a physical reaction and regulate metabolic pathways.
Metabolic chains and components are absolutely identical for many species, which is proof of the unity of the origin of all living beings. This similarity shows the relatively early appearance of evolution in the history of the development of organisms.
Classification by type of metabolism
What is metabolism in biology is described in detail in this article. All living organisms that exist on planet Earth can be divided into eight groups, guided by the source of carbon, energy and oxidized substrate.
Living organisms can use the energy of chemical reactions or light as a source of nutrition. As an oxidizable substrate, both organic and carbon sources can be carbon dioxide or organics.
There are microorganisms that, being in different conditions of existence, use a different type of metabolism. It depends on humidity, lighting and other factors.
Can be characterized by the fact that the same organism can have cells with different type metabolic processes.
catabolism
Biology examines the metabolism and energy through such a concept as "catabolism". This term is called during which large particles of fats, amino acids and carbohydrates are broken down. During catabolism, simple molecules appear that participate in biosynthetic reactions. It is thanks to these processes that the body is able to mobilize energy, turning it into an accessible form.
In organisms that live by photosynthesis (cyanobacteria and plants), the electron transfer reaction does not release energy, but stores it, thanks to sunlight.
In animals, catabolism reactions are associated with the breakdown of complex elements into simpler ones. These substances are nitrates and oxygen.
Catabolism in animals is divided into three stages:
- The breakdown of complex substances into simpler ones.
- Breaking down simple molecules into even simpler ones.
- Release of energy.
Anabolism
Metabolism (grade 8 biology considers this concept) is also characterized by anabolism - a set of metabolic processes of biosynthesis with energy consumption. Complex molecules, which are the energy basis of cellular structures, are sequentially formed from the simplest precursors.
First, amino acids, nucleotides and monosaccharides are synthesized. Then the above elements become active forms due to the energy of ATP. And at the last stage, all active monomers are combined into complex structures, such as proteins, lipids and polysaccharides.
It is worth noting that not all living organisms synthesize active molecules. Biology (metabolism is described in detail in this article) distinguishes organisms such as autotrophs, chemotrophs and heterotrophs. They receive energy from alternative sources.
Energy from sunlight
What is metabolism in biology? The process by which all life exists on Earth, and distinguishes living organisms from inanimate matter.
Some protozoa, plants and cyanobacteria feed on the energy of sunlight. In these representatives, the metabolism occurs due to photosynthesis - the process of absorbing oxygen and releasing carbon dioxide.
Digestion
Molecules such as starch, proteins and cellulose are broken down before they are used by cells. In the process of digestion, special enzymes take part, which break down proteins into amino acids, and polysaccharides - into monosaccharides.
Animals can secrete such enzymes only from special cells. But microorganisms release such substances into the surrounding space. All substances that are produced due to extracellular enzymes enter the body with the help of "active transport".
Control and regulation
What is metabolism in biology, you can read in this article. Each organism is characterized by homeostasis - the constancy of the internal environment of the body. The presence of such a condition is very important for any organism. Since they are all surrounded by an environment that is constantly changing, in order to maintain optimal conditions inside the cells, all metabolic reactions must be correctly and accurately regulated. A good metabolism enables living organisms to constantly contact the environment and respond to its changes.
Historical information
What is metabolism in biology? The definition is at the beginning of the article. The concept of "metabolism" was first used by Theodor Schwann in the forties of the nineteenth century.
Scientists have been studying metabolism for several centuries, and it all began with attempts to study animal organisms. But the term "metabolism" was first used by Ibn al-Nafis, who believed that the whole body is constantly in a state of nutrition and decay, therefore, it is characterized by constant changes.
The biology lesson "Metabolism" will reveal the whole essence of this concept and describe examples that will help increase the depth of knowledge.
The first controlled experiment in the study of metabolism was made by Santorio Santorio in 1614. He described his condition before and after eating, working, drinking water and sleeping. He was the first to notice that most of the food consumed was lost during the process of "imperceptible evaporation."
In the initial studies, metabolic reactions were not found, and scientists believed that living tissue was controlled by a living force.
In the twentieth century, Eduard Buchner introduced the concept of enzymes. Since then, the study of metabolism began with the study of cells. During this period, biochemistry became a science.
What is metabolism in biology? The definition can be given as follows - this is a special set of biochemical reactions that support the existence of an organism.
Minerals
play a very important role in metabolism organic matter. All organic compounds are made up of large amounts of phosphorus, oxygen, carbon and nitrogen.
Most inorganic compounds allow you to control the level of pressure inside the cells. Also, their concentration has a positive effect on the functioning of muscle and nerve cells.
(iron and zinc) regulate the activity of transport proteins and enzymes. All inorganic trace elements are absorbed due to transport proteins and never remain in a free state.
Metabolism
Metabolism is the main vital property of the body, with the cessation of metabolism, death occurs. Metabolism includes two interrelated processes: the assimilation of substances entering the body - assimilation and their decay - dissimilation. In the process of assimilation, complex organic substances are formed, which are used to build body cells and intercellular structures, and during dissimilation, complex organic substances decompose, turning into simpler ones. The process of dissimilation is accompanied by the release of a significant amount of energy necessary for the life of the organism. The final decay products that are not involved in further transformations are removed from the body. The main feature of the process of dissimilation
is that during the oxygen decomposition process, most of the energy (about 55%) is stored in the form of ATP and 55%) is stored in the form of ATP and substances (mainly in the new synthesis of organic substances).
The metabolism involves proteins, fats, carbohydrates, water, mineral salts and vitamins. All metabolic processes are interconnected. The intensity of metabolism depends on the age of the person, the nature of the work performed, climatic and other factors. Metabolism is regulated nervous system and humoral factors. In diseases, various changes in metabolism occur, sometimes they are the main signs of the disease. For example, with gout, the content of uric acid in the blood is increased and it is deposited in the joints, tendons and cartilage. Changes in metabolism can be observed in violation of the activity of the endocrine glands, insufficient intake of vitamins in the body, with damage to some parts of the nervous system, such as the hypothalamus.
Proteins that enter the body with food, under the influence of digestive tract enzymes, break down to amino acids, which are absorbed into the blood and carried by it throughout the body. In the cells of organs and tissues, proteins are synthesized from them, human. The unused part of the proteins undergoes decay and is removed from the body, and the released energy is used in other reactions (energy function of proteins). Proteins are necessary not only for the construction of cellular structures (building function), but are integral part enzymes, hormones and some other substances. Proteins are part of enzymes as catalysts for many reactions (catalytic function) and antibodies (protective function).
The end products of protein breakdown in the body are water, carbon dioxide and nitrogen-containing substances (ammonia, uric acid, etc.). Protein breakdown products are excreted from the body through the excretory organs. Proteins in the body are not deposited in the reserve (or almost not deposited). In a healthy adult body, the amount of nitrogen taken in is equal to the amount excreted, i.e. protein breaks down as much as it enters (nitrogen balance). In a growing child's body, protein synthesis exceeds their breakdown (positive nitrogen balance). In severe illness and starvation, as well as often in very old people, a negative nitrogen balance can be observed: the amount of nitrogen excreted exceeds the amount introduced. Proteins contain on average 16% nitrogen, i.e. the weight of proteins is 6.25 times the weight of the nitrogen present in them (calculated per 100 g of protein). The resulting amount of nitrogen is multiplied by 6.25 and the amount of protein in grams is obtained. daily requirement in proteins - an average of 100-118 g; it depends on age, the nature of the profession and other conditions. A prolonged lack of proteins causes severe disorders in the body: growth and development retardation in children, changes in the enzymatic systems of the body, in the endocrine glands, etc. A positive nitrogen balance in an adult can be with the growth of neoplasms - the growth of cells that are not characteristic of the body. If this process is detected in time, then timely treatment is possible.
Complex carbohydrates that enter the body with food are broken down in the digestive tract to monosaccharides, which enter the blood, and then to the liver, where glycogen is synthesized from glucose. As needed, it turns back into glucose, which is carried throughout the body by the blood. The content of glucose in the blood is maintained at the same level (about 0.1%). The liver regulates blood sugar: it contains about 300 g of carbohydrates in the form of glycogen. With the intake of a significant amount of sugar or glucose (150-200 g) with food, the blood sugar level rises (food hyperglycemia). Excess sugar is excreted in the urine, i.e. glucose appears in the urine - glucosuria occurs. In case of violation of the intrasecretory activity of the pancreas, a disease occurs, which is called sugar disease, or diabetes mellitus. In diabetes mellitus, the blood sugar level rises and an increased excretion of sugar in the urine begins (up to 500 g of sugar can be excreted in the urine during the day). Glycogen is deposited not only in the liver, it can accumulate in the muscles. When needed, glucose enters the bloodstream from both liver glycogen and muscle glycogen. Glucose is not only a structural component of the cytoplasm of cells, but also a necessary component of their growth (an energy source), it is very important for the functioning of the nervous system (glycogen is also deposited in nerve cells). If the concentration of sugar in the blood drops to 0.04%, then convulsions, delirium, loss of consciousness, etc. begin. - the activity of the central nervous system is disturbed. It is enough to give such a patient to eat ordinary sugar or to introduce glucose into the blood, and all disorders disappear. A sharp and prolonged decrease in blood sugar - hypoglycemia can lead to more severe disturbances in the body's activity and lead to death. With insufficient intake of carbohydrates with food, they can be formed from proteins and fats.
Carbohydrates break down easily and are the main source of energy in the body, especially during physical exertion. The daily human need for carbohydrates averages 450-500 g. The center for the regulation of blood sugar is located in the medulla oblongata and intermediate (hypotuberous region) brain. Higher centers are located in the cerebral cortex. Adrenaline - a hormone of the adrenal medulla - promotes the conversion of glycogen into glucose and enhances oxidative processes in cells. Its action is opposite to insulin, which promotes the penetration of glucose into cells and the synthesis of glycogen. Other hormones also take part in the regulation of carbohydrate metabolism: the hormones of the adrenal cortex, the anterior pituitary gland and the thyroid gland.
Fats, like carbohydrates, are used by the body as a source of energy. During the oxidation of fat, more than two times more energy is released than during the oxidation of the same amount of carbohydrates and proteins: during the oxidation of 1 g of fat, 9.3 kcal of heat is released, 1 g of carbohydrates - 4.1 kcal, 1 g of protein - 4.1 kcal.
The glycerol formed during the breakdown of fats is easily absorbed, and fatty acids are absorbed only after saponification. In the human body, glycerol and fatty acids form fat, which is unique to the human body. Fat is part of the cells, and unclaimed amounts of fat are deposited in the reserve in the form of fat droplets. Fat is deposited mainly in the subcutaneous tissue, omentum, around the kidneys, and is found in the liver and muscles. In humans, fat is 10-20% of the weight, and in obesity - up to 50%. Obesity disrupts metabolic processes. Fat is synthesized not only from consumed fat, but also from proteins and carbohydrates. During starvation, carbohydrates are formed from fats, which are used as a source of energy. In the regulation of fat metabolism, the central nervous system plays an important role, as well as many endocrine glands (genital, pituitary, thyroid, adrenal glands).
The hormonal regulation of protein metabolism is even less studied than the hormonal regulation of lipid metabolism. Since growth consists in the deposition of a new protein in the cytoplasm, the pituitary growth hormone plays a role in this regulation, but little is known about its mechanism of action. Insulin, sex hormones and cortisol secreted by the adrenal cortex also participate in the regulation of protein metabolism. A very important role in preserving the life of the body is played by the metabolism of lipids, or fat-like substances that make up the nervous tissue and participate in its activity. In their structure, lipoids are close to some hormones and, apparently, are the basis for the formation of sex hormones, the hormone of the adrenal cortex and vitamin D.
Water and mineral salts are not sources of energy and nutrients, but their role is extremely important. Water makes up to 65% of body weight, and in children - up to 80%. Without food, but in the presence of water (its consumption), a person can do 40-50 days, and without water, he dies after a few days. Water and mineral salts create the internal environment of the body, being the main part of the plasma, lymph and tissue fluid. Mineral salts dissolved in water maintain a constant osmotic pressure necessary for the normal functioning of body cells. Small amounts of water are formed in the body during oxidation nutrients, especially a lot of it is obtained during the oxidation of fats (118 g of water during the oxidation of 100 g of fats). Water enters the body when drinking and with food, is excreted mainly by the kidneys (1.5 l), partially - with exhaled air (500 ml) and by evaporation from the skin surface (500 ml). The daily requirement of an adult in water is 2-2.5 liters, it may vary depending on climatic conditions and working conditions. In hot weather, water is consumed in large quantities, as well as when working in hot shops. Water is a solvent of many substances, all physical and chemical reactions of the body take place in it, it plays an important role in the transport of substances. The ratio of the amount of water consumed to the amount allocated is called the water balance; it is important that the inflow of water covers the consumption, otherwise, as a result of the loss of water, serious violations of the body's vital functions occur.
With food, about 15 chemical elements are introduced into the body, some of which come in negligible amounts. A person needs up to 10 g of salt per day, 1 g of potassium, 0.3 g of magnesium, 1.5 g of phosphorus, 0.8 g of calcium, 0.012 g of iron, 0.001 mg of copper, 0.0003 g of manganese and 0.00003 g iodine. Salts are distributed unevenly in different cells and tissues of the body. So, a lot of sodium salts are found in plasma and intercellular fluid; there are more potassium salts in cells than in body fluids; bones contain a lot of calcium and phosphorus; hemoglobin - copper and iron, and thyroid cells - iodine. Since minerals are constantly excreted from the body, they must be replenished in equal amounts with food intake. The lack of salt in the diet can lead to death faster than complete starvation. The need for table salt is due to the fact that its solution plays a major role in maintaining osmotic pressure. Calcium salts are necessary to maintain the activity of the heart: in their absence, the activity of the heart slows down and soon stops completely. The ratio of potassium and calcium salts is also important for the normal functioning of the heart muscle. Ions of sodium, potassium, calcium and chlorine play a role in the processes of excitation and inhibition, muscle contraction. Salts that are needed in minimal amounts (trace elements) are also important for the normal functioning of the body (for example, cobalt is part of vitamin B12; zinc is part of the enzyme - carbonic anhydrase, which binds carbon dioxide in the blood; fluorine prevents tooth decay, etc.) .
Rational nutrition should fully cover the human need for energy and plastic substances. The daily diet of a person who is not engaged in physical labor should include about 100 g of protein, 90 g of fat and 400 g of carbohydrates (about 3,000 kcal); mineral salts, vitamins and water are needed. With physical activity, the need for energy and plastic substances increases, in connection with this, the content of not only fats and carbohydrates, but also proteins, should increase in the diet.
It is recommended to consume about 50% of proteins and fats in the form of animal products and, with an increase in the calorie content of food, maintain the ratio of proteins, fats and carbohydrates - 1:1:4. In this ratio, products are better absorbed. One-sided nutrition (the predominance of either protein or carbohydrate foods) is not advisable, since it disrupts the processes of digestion and metabolism. To reduce body weight, you should reduce your intake of carbohydrates.
Daily energy requirement for individuals
(in kilocalories)
Mental workers
People employed in
mechanized production
manual workers
(partial or missing
mechanization)
Persons performing heavy
muscle work
The metabolism is accompanied by the exchange of energy - both processes are interconnected. The energy released during dissimilation is spent in the form of mechanical (in muscles), electrical (nervous and other tissues), chemical (synthesis of new substances) and other types of energy. It is important that all these types of energy are converted into heat released into the environment. The intensity of metabolism can be determined by the amount of heat generated in the body. On average, the human body absorbs about 90% of the incoming nutrients. Energy consumption in the body can be accounted for. With direct calorimetry, the amount of released heat is determined in special chambers, with indirect calorimetry, using special devices, the volume of inhaled oxygen and exhaled carbon dioxide (gas exchange) is determined and the respiratory coefficient is calculated (the ratio of the volume of exhaled carbon dioxide to the volume of absorbed oxygen - CO2 / O2), using which, according to special tables, you can calculate the energy consumption.
Basic metabolism - the amount of energy consumed by the body only to maintain life, i.e. on the processes occurring at complete rest (heart function, contraction of the respiratory muscles, urination, hormone secretion, etc.). The value of the basic exchange varies depending on the sex, weight, age of the person and other factors. It ranges from 1,000 to 2,000 large calories per day for adult men and from 1,000 to 1,700 for women (an average of 24 large calories per kilogram of body weight). During physical exertion, in addition to the main metabolism, an additional expenditure of energy (working metabolism of the body) occurs. The total energy expenditure, therefore, is the sum of the main and working exchanges and, with high physical exertion, can reach 5,000 or more calories. There is a direct relationship between metabolism and heat generation: an increase in metabolism is accompanied by an increase in heat generation and, conversely, with a decrease in metabolism, heat generation also decreases. Heat transfer is carried out through the skin during the evaporation of sweat, with exhaled air, with urine and feces. The regulation of heat transfer is based largely on changes in the volume of blood flowing through the vessels of the skin, and on the intensity of sweating. With the expansion of skin vessels and increased blood flow, heat transfer increases, and with vasoconstriction and a decrease in blood flow, it decreases. The process of heat transfer and heat generation is regulated by the nervous system - the "thermal center" is located in the intermediate section of the brain.
In the body of a healthy person, there is a balance between the formation of heat and its return: as much heat is released into the environment as it is generated, due to which the body temperature is maintained at the same level. The average body temperature when measured in the armpit is 36.5-36.9 oC. The lowest temperature is observed from 4 to 6 o'clock, the highest - from 16 to 18 o'clock. With the disease, an increase in body temperature is observed due to a violation of thermoregulation; its increase above 41 oC is threatening for the body, as life processes that occur at certain temperature limits are disrupted. At high temperatures, the metabolism increases sharply: the breakdown of one's own proteins (negative nitrogen balance) increases, the work of the heart and breathing become more frequent, blood pressure rises, etc. With intense muscular work, an increase in temperature can lead to heat stroke, especially in conditions high temperature air. With prolonged cooling, the body temperature may decrease compared to normal, i.e. hypothermia may develop. In hot climates or in hot workshops, perspiration is the main means of cooling the body. A person per day can lose up to 9-15 liters of water with sweat and give off 5,000-9,000 kcal of heat (1 ml of water takes 0.58 kcal). When the temperature of the external environment changes, the work of the endocrine glands reflexively changes: the thyroid gland, adrenal glands and pancreas (their hormones enhance oxidative processes). The pituitary gland inhibits the secretion of thyroid hormone, reduces metabolism and lowers body temperature.
With the environment and adaptation to change external conditions. The basis of metabolism is the interrelated processes of anabolism and catabolism, aimed at the continuous renewal of living material and providing it with the necessary energy. Anabolic and catabolic processes are carried out by successive chemical reactions involving enzymes. Each species of organisms is characterized by a special, genetically fixed type of metabolism, depending on the conditions of its existence. The intensity and direction of metabolism in the cell is ensured by complex regulation of the synthesis and activity of enzymes, as well as by changes in the permeability of biological membranes. In humans and animals, hormonal regulation of metabolism takes place, coordinated by the central nervous system. Any disease is accompanied by metabolic disorders; genetically determined metabolic disorders are the cause of many hereditary diseases.
Big Encyclopedic Dictionary. 2000 .
Synonyms:See what "METABOLISM" is in other dictionaries:
Metabolism, the totality of chemical processes occurring in living organisms. transformations that ensure their growth, vital activity, reproduction, constant contact and exchange with the environment. Thanks to O. v. splitting and synthesis of molecules occurs, ... ... Biological encyclopedic Dictionary
Modern Encyclopedia
Metabolism- (metabolism), a set of chemical transformations in organisms that ensure their growth, vital activity and reproduction. The basis of metabolism is the interrelated processes of synthesis (anabolism) and decay (catabolism), aimed at ... ... Illustrated Encyclopedic Dictionary
See Metabolism. Ecological encyclopedic dictionary. Chisinau: Main edition of the Moldavian Soviet encyclopedia. I.I. Grandpa. 1989. Metabolism of the transformation of substances (and energy) in organisms, ensuring their viability ... Ecological dictionary
Metabolism Dictionary of Russian synonyms. metabolism n., number of synonyms: 1 metabolism (3) ASIS synonym dictionary. V.N. Trishin ... Synonym dictionary
EXCHANGE, a, m. Dictionary Ozhegov. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Explanatory dictionary of Ozhegov
See metabolism. (Source: "Microbiology: a dictionary of terms", Firsov N.N., M: Bustard, 2006) ... Dictionary of microbiology
metabolism- - Topics of biotechnology EN metabolism ... Technical Translator's Handbook
The liver is the most important organ of metabolism in animals (photo of a rat's liver) Metabolism (from the Greek μεταβολή, "transformation, change"), metabolism is the complete process of transformation of chemicals in the body, ensuring its growth, development, ... ... Wikipedia
Or metabolism, the natural order of the transformation of substances and energy in living systems, which is the basis of life, aimed at their conservation and self-reproduction; the totality of all chemical reactions that take place in the body. F. Engels, ... ... Great Soviet Encyclopedia
Books
- Metabolism and energy conversion in plants. In 2 parts. Part 2, Famintsyn A.S. This publication is devoted to plant physiology. The book consists of two parts. In the first part, the processes of plant nutrition are considered from a general biological point of view. In the second part…
A prerequisite for the existence of any living organism is the constant supply of nutrients and the removal of end products of decay.
What is metabolism in biology
Metabolism, or metabolism, is a special set of chemical reactions that take place in any living organism to maintain its activity and life. Such reactions give the body the opportunity to develop, grow and multiply, while maintaining its structure and responding to environmental stimuli.
Metabolism is usually divided into two stages: catabolism and anabolism. At the first stage, all complex substances are broken down and become simpler. On the second, along with energy costs, nucleic acids, lipids and proteins are synthesized.
The most important role in the process of metabolism is played by enzymes, which are active biological catalysts. They are able to reduce the activation energy of a physical reaction and regulate metabolic pathways.
Metabolic chains and components are absolutely identical for many species, which is proof of the unity of the origin of all living beings. This similarity shows the relatively early appearance of evolution in the history of the development of organisms.
Classification by type of metabolism
What is metabolism in biology is described in detail in this article. All living organisms that exist on planet Earth can be divided into eight groups, guided by the source of carbon, energy and oxidized substrate.
Living organisms can use the energy of chemical reactions or light as a source of nutrition. Both organic and inorganic substances can be used as an oxidizable substrate. The source of carbon is carbon dioxide or organic matter.
There are microorganisms that, being in different conditions of existence, use a different type of metabolism. It depends on humidity, lighting and other factors.
Multicellular organisms can be characterized by the fact that the same organism can have cells with different types of metabolic processes.
catabolism
Biology examines the metabolism and energy through such a concept as "catabolism". This term refers to metabolic processes during which large particles of fats, amino acids and carbohydrates are broken down. During catabolism, simple molecules appear that participate in biosynthetic reactions. It is thanks to these processes that the body is able to mobilize energy, turning it into an accessible form.
In organisms that live by photosynthesis (cyanobacteria and plants), the electron transfer reaction does not release energy, but stores it, thanks to sunlight.
In animals, catabolism reactions are associated with the breakdown of complex elements into simpler ones. These substances are nitrates and oxygen.
Catabolism in animals is divided into three stages:
- The breakdown of complex substances into simpler ones.
- Breaking down simple molecules into even simpler ones.
- Release of energy.
Anabolism
Metabolism (grade 8 biology considers this concept) is also characterized by anabolism - a set of metabolic processes of biosynthesis with energy consumption. Complex molecules, which are the energy basis of cellular structures, are sequentially formed from the simplest precursors.
First, amino acids, nucleotides and monosaccharides are synthesized. Then the above elements become active forms due to the energy of ATP. And at the last stage, all active monomers are combined into complex structures, such as proteins, lipids and polysaccharides.
It is worth noting that not all living organisms synthesize active molecules. Biology (metabolism is described in detail in this article) distinguishes organisms such as autotrophs, chemotrophs and heterotrophs. They receive energy from alternative sources.
Energy from sunlight
What is metabolism in biology? The process by which all life exists on Earth, and distinguishes living organisms from inanimate matter.
Some protozoa, plants and cyanobacteria feed on the energy of sunlight. In these representatives, the metabolism occurs due to photosynthesis - the process of absorbing oxygen and releasing carbon dioxide.
Digestion
Molecules such as starch, proteins and cellulose are broken down before they are used by cells. In the process of digestion, special enzymes take part, which break down proteins into amino acids, and polysaccharides - into monosaccharides.
Animals can secrete such enzymes only from special cells. But microorganisms release such substances into the surrounding space. All substances that are produced due to extracellular enzymes enter the body with the help of "active transport".
Control and regulation
What is metabolism in biology, you can read in this article. Each organism is characterized by homeostasis - the constancy of the internal environment of the body. The presence of such a condition is very important for any organism. Since they are all surrounded by an environment that is constantly changing, in order to maintain optimal conditions inside the cells, all metabolic reactions must be correctly and accurately regulated. A good metabolism enables living organisms to constantly contact the environment and respond to its changes.
Historical information
What is metabolism in biology? The definition is at the beginning of the article. The concept of "metabolism" was first used by Theodor Schwann in the forties of the nineteenth century.
Scientists have been studying metabolism for several centuries, and it all began with attempts to study animal organisms. But the term "metabolism" was first used by Ibn al-Nafis, who believed that the whole body is constantly in a state of nutrition and decay, therefore, it is characterized by constant changes.
The biology lesson "Metabolism" will reveal the whole essence of this concept and describe examples that will help increase the depth of knowledge.
The first controlled experiment in the study of metabolism was made by Santorio Santorio in 1614. He described his condition before and after eating, working, drinking water and sleeping. He was the first to notice that most of the food consumed was lost during the process of "imperceptible evaporation."
In the initial studies, metabolic reactions were not found, and scientists believed that living tissue was controlled by a living force.
In the twentieth century, Eduard Buchner introduced the concept of enzymes. Since then, the study of metabolism began with the study of cells. During this period, biochemistry became a science.
What is metabolism in biology? The definition can be given as follows - this is a special set of biochemical reactions that support the existence of an organism.
Minerals
play an important role in metabolism inorganic substances. All organic compounds are made up of large amounts of phosphorus, oxygen, carbon and nitrogen.
Most inorganic compounds allow you to control the level of pressure inside the cells. Also, their concentration has a positive effect on the functioning of muscle and nerve cells.
Transition metals (iron and zinc) regulate the activity of transport proteins and enzymes. All inorganic trace elements are absorbed due to transport proteins and never remain in a free state.
Metabolism or metabolism- this is a complete complex of chemical reactions and processes that occur in a living cell, ensuring its vital activity, growth, division and interaction with the external environment.
Exactly right metabolism ensures the breakdown and assimilation of molecules of substances that make up cells or are necessary for the functioning, destruction, renewal of cells and intercellular substance. Thanks to proper metabolism, the tissue cover of the body is updated in 80 days, muscle fiber proteins are updated in 180 days, liver cells and blood serum are updated in 10 days, and some liver enzymes are renewed in just 2-4 hours.
Metabolism inextricably linked to the process energy conversion. As a result of chemical reactions, potential energy from complex organic molecules is converted into other types of energy, which is used for all life processes of cells. All these processes proceed with the participation of catalysts - enzymes. For each species of living organisms, the metabolism is unique, peculiar only to this species. The metabolism of each species is determined primarily by the conditions of its habitat and existence in general.
The metabolism consists of two main processes, which are inextricably linked with each other and proceed simultaneously:
- Anabolism (assimilation);
- Catabolism (dissimilation).
Anabolism ( plastic exchange) are the processes of synthesis (construction) of complex organic molecules from simpler ones obtained as a result of catabolism.
Catabolic processes are a complex of chemical reactions for the breakdown of large molecules into smaller ones that could pass into the cell. At the same time, energy is released, which organisms usually store in ATP molecules ( adenosine triphosphate). Catabolism usually occurs during oxidative or hydrolytic reactions. At the same time, such processes proceed both with the participation of oxygen ( breath, aerobic pathway), and without its participation (fermentation, glycolysis - anaerobic pathway).
Depending on the type of metabolism, there is two types of living organisms:
1) Heterotrophs- These are organisms that synthesize organic compounds due to the products that are formed as a result of catabolism and the energy released in the process. The initial raw materials for the formation of tissues of such organisms are simple organic substances. From these compounds, each cell individually synthesizes the compounds it needs. Thus, protein synthesis can occur locally (glycogen is synthesized directly in the muscles, and not supplied with blood from the liver).
2) Autotrophs- these are organisms that can synthesize organic compounds from carbon dioxide using oxidation reactions ( chemosynthesis) and sunlight ( photosynthesis). Such organisms are some types of bacteria and green plants.
With the development of living organisms during evolution, the regulatory systems have become more complex and ordered. Today, highly developed organisms have additional regulatory hormonal mechanisms And neural mechanisms, which either directly act on the synthesis of enzymes or on the enzymes themselves, and can also affect the sensitivity of cells to a particular enzyme.
