The processes of assimilation and dissimilation are examples. What types of biochemical reactions occur in assimilation and dissimilation? What is assimilation in biology?

Dissimilation (catabolism) is a set of processes in which complex organic substances are oxidized and converted into inorganic substances (water, carbon dioxide, urea (a simple organic substance), etc.), accompanied by the synthesis of ATP, which is used by the body in assimilation processes and other processes vital activity of the body.

The main function of dissimilation processes in the body is the transfer of energy from an “inconvenient” form for the body (the energy of chemical bonds of complex organic substances - proteins, carbohydrates, fats) into a “convenient” form - high-energy bonds of compounds such as ATP and ADP, which are easily transferred due to phosphorylation processes from one connection to another. This is one of the biological and ecological functions of assimilation. Another such function is the implementation of the cycle of substances, when organic substances are converted into inorganic substances, and the latter re-enter the cycle, participating in the formation of organic substances.

The transfer of energy from an “inconvenient” form for the body to a “convenient” one occurs due to the conversion of first AMP into ADP, and then ADP into ATP.

The transformations of adenosine phosphates with the formation of high-energy bonds are expressed by the following schemes: AMP + H 3 PO 4 → ADP + H 2 O (energy absorption); ADP + H 3 PO 4 = ATP + H 2 O (energy absorption).

As a result of dissimilation processes, ATP accumulates, which is then used in assimilation processes, and the energy contained in the high-energy bonds of ATP molecules is transferred to other molecules either through phosphorylation processes (the residue is transferred from the ATP molecule to other molecules), or through hydrolysis of ATP and its conversion to ADP and phosphoric acid.

Organisms, according to the nature of their participation in the processes of dissimilation of molecular oxygen, are divided into anaerobic (oxygen-free) and aerobic (oxygen-free). In anaerobic organisms, dissimilation is carried out due to fermentation, and in aerobic organisms - due to the broad understanding of the essence of this concept.

Fermentation is a set of processes of decomposition of complex organic substances into simpler ones, accompanied by the release of energy and the synthesis of ATP.

In nature, the most common types of fermentation are lactic acid and alcoholic. As a way to “extract” energy, fermentation is an ineffective process: for example, during lactic acid fermentation, 2 moles of ATP are formed from 1 mole of glucose.

1. Lactic acid fermentation is an anaerobic process of breakdown of glucose into lactic acid. Expressed by the scheme:

C 6 H 12 O 6 (glucose) → 2CH 3 CH(OH)COOH (lactic acid)

(energy is released, under the influence of which two ATP molecules are synthesized).

This type of fermentation is characteristic of lactic acid bacteria, in the presence of which milk sours.

Lactic acid fermentation is one of the stages of the respiration process (in the broad sense) in aerobic organisms, including humans.

2. Alcoholic fermentation is an aerobic process of glucose breakdown, accompanied by the formation of ethyl alcohol and carbon dioxide; proceeds according to the following scheme:

C 6 H 12 O 6 (glucose) → 2CO 2 + 2C 2 H 5 OH (ethyl alcohol)

(energy is released, used for ATP synthesis).

This type of fermentation occurs in fruits and other plant organs located in an anaerobic environment.

In nature, another method of dissimilation is most widespread - respiration, which occurs in an oxidizing environment, i.e., an environment containing molecular oxygen. The respiration process consists of two parts: gas exchange and a complex sequence of biochemical processes of oxidation of organic compounds, the end products of which are carbon dioxide, ammonia (converted into other substances) and some other compounds (hydrogen sulfide, inorganic phosphorus compounds, etc.).

In everyday life, breathing is considered as a process of gas exchange (this is an understanding of the concept of “breathing” in the narrow sense). Thus, zoologists distinguish the respiratory system in the organisms of higher animals - gas exchange occurs in these organs, as a result of which CO 2 is removed from the body, and O 2 enters the body (we “breathe”, i.e. we release carbon dioxide and absorb molecular oxygen ).

In this manual, breathing is considered in the broad sense of the word as a set of processes of gas exchange, the transfer of gases throughout the body and a set of chemical processes in which complex organic substances are converted into inorganic ones, while energy is absorbed by the body in the form of ATP, synthesized in the process of dissimilation.

So, the breathing process in a broad sense consists of two phases: gas exchange and a set of chemical processes of energy release and ATP synthesis. Let us briefly describe these phases.

1. Gas exchange.

For single-celled and relatively simply structured organisms (both plants, animals and fungi), gas exchange occurs over the entire surface of the body: oxygen enters the cells, and carbon dioxide is released into the environment. In higher plants, the role of respiratory organs is played by either stomata (leaves) or specially arranged pores (lentils) in the bark of perennial organs (stems, roots); in addition, the roots absorb oxygen and release carbon dioxide through root hairs. Highly organized multicellular animals have complex respiratory organs - these are either gills (in aquatic animals), or lungs (higher animals such as Vertebrates), or a tracheal system (insects).

Let's consider gas exchange using the example of a person - a representative of the Vertebrate type. This process is quite complex and begins in the lungs, in which in the capillaries of the alveoli, blood enriched with CO 2 (venous) comes into contact with air rich in oxygen (entered the lungs during inhalation), due to which carbon dioxide is released in the lungs, and molecular oxygen interacts with hemoglobin in the blood, forming a scarlet compound - oxyhemoglobin (O 2 displaces CO 2 from its connection with hemoglobin). CO 2 contained in the blood plasma also diffuses into the lung cavity. The resulting arterial blood flows through the veins of the lungs into the left atrium, and from it into the left ventricle and aorta. Next, the blood is carried through the blood vessels to the tissues of various organs and through the capillaries in the tissues, carbon dioxide from the tissue fluid (CO 2 entered the tissue fluid from the cells) enters the red blood cells, partially reacting with oxyhemoglobin, and partially dissolving in the cell plasma. Molecular oxygen diffuses first into the tissue fluid and then into the cells. As a result of the described processes, venous blood is formed in the tissues, which flows from the capillaries into the veins, and then into the right atrium, the right ventricle, from which it enters the lungs through the pulmonary arteries and the process is repeated.

2. Characteristics of chemical oxidation processes during dissimilation.

The chemistry of the “release of energy” contained in complex biochemical compounds is complex and occurs in three stages.

Stage 1 - preparatory.

This stage occurs in any organism and consists of the fact that complex organic substances are converted into simpler ones ( - into a mixture of natural alpha amino acids; polysaccharides - into monosaccharides; - into a mixture of glycerol and fatty acids). During this stage, a small amount of energy is released, which the body practically does not use - it dissipates.

Stage 2 - anaerobic.

It represents fermentation processes. The most important fermentation process is lactic acid fermentation, which can be represented by the diagram:

C 6 H 12 O 6 (glucose) + 2ADP + 2H 3 PO 4 → 2 ATP + 2H 2 O + CH 3 CH(OH)COOH (lactic acid)

This stage is necessary for organisms to implement their physiological functions (performing mechanical work, moving the body in space, etc.). In addition, lactic acid is a substance entering the third stage.

Stage 3 - aerobic.

To carry out this stage, molecular oxygen is required. It is realized in special cell organelles - mitochondria (they are figuratively called “energy stations of the cell”). The aerobic stage is a complex chain of transformations that results in the formation of inorganic substances. If glucose undergoes transformations, then the aerobic stage can be schematically depicted as follows:

2CH 3 CH(OH)COOH (lactic acid) + 6O 2 + 36 ADP + 36 H 3 P04 6CO 2 + 42H 2 O + 36 ATP

Two molecules of lactic acid are taken because from one molecule of glucose during lactic acid fermentation two molecules of acid are formed.

So, with the complete breakdown of one glucose molecule to CO 2 and H 2 O, 38 (36 + 2) ATP molecules are synthesized, which corresponds to 55% absorption of the energy that is released during the complete oxidation of glucose to the above products.

Concluding the consideration of dissimilation processes, it should be noted the difference in the gas exchange of plants and animals, and for the gas exchange of plants - the difference in gas exchange during the day and at night. It should be remembered that both plants and animals have the same gas exchange at night - the body absorbs oxygen and releases CO 2 into the environment. During the day, gas exchange in plants consists of the fact that the plant absorbs CO 2 in the light and releases O 2 into the environment (in animals, on the contrary, CO 2 is released and oxygen is absorbed). From the above, an ecological conclusion about the features of the home follows: you should not keep many plants in the bedroom (Justify why).

The synthesis of substances that occurs in a cell is called biological synthesis, or biosynthesis for short.

All biosynthesis reactions involve the absorption of energy.

The set of biosynthesis reactions is called plastic metabolism or assimilation (Latin “similis” - similar). The meaning of this process is that food substances entering the cell from the external environment, which are sharply different from the cell substance, become cell substances as a result of chemical transformations.

Cleavage reactions. Complex substances break down into simpler ones, and high-molecular substances into low-molecular ones. Proteins break down into amino acids, starch into glucose. These substances are broken down into even lower molecular weight compounds, and in the end very simple, energy-poor substances are formed - CO 2 and H 2 O. Splitting reactions in most cases are accompanied by the release of energy. The biological significance of these reactions is to provide the cell with energy. Any form of activity - movement, secretion, biosynthesis, etc. - requires energy expenditure.

The set of cleavage reactions is called cellular energy metabolism or dissimilation. Dissimilation is the exact opposite of assimilation: as a result of splitting, substances lose their resemblance to cell substances.

Plastic and energy exchanges (assimilation and dissimilation) are inextricably linked. On the one hand, biosynthesis reactions require the expenditure of energy, which is drawn from cleavage reactions. On the other hand, to carry out energy metabolism reactions, constant biosynthesis of enzymes servicing these reactions is necessary, since during operation they wear out and are destroyed.

The complex systems of reactions that make up the process of plastic and energy exchanges are closely connected not only with each other, but also with the external environment. Food substances enter the cell from the external environment, which serve as material for plastic exchange reactions, and in splitting reactions they release the energy necessary for the functioning of the cell. Substances that can no longer be used by the cell are released into the external environment.

The totality of all enzymatic reactions of the cell, i.e., the totality of plastic and energy exchanges (assimilation and dissimilation) connected with each other and with the external environment, is called metabolism and energy. This process is the main condition for maintaining the life of the cell, the source of its growth, development and functioning .

18 Adenosine diphosphate (ADP) and adenosine triphosphate (ATP), their structure, localization and role in cell energy metabolism.

19. Metabolism and energy in the cell. Photosynthesis, chemosynthesis. Assimilation process (basic reactions). Metabolism is a unity of assimilation and dissimilation. Dissimilation is an exothermic process, i.e. the process of releasing energy due to the breakdown of cell substances. Substances formed during dissimilation also undergo further transformations. Assimilation is the process of assimilation of substances entering a cell to specific substances characteristic of a given cell. Assimilation is an endothermic process that requires energy. The source of energy is previously synthesized substances that have undergone decay during the process of dissimilation. Photosynthesis is the process of converting the energy of sunlight into the energy of chemical compounds. Photosynthesis is the process of formation of organic substances (glucose and then starch) from inorganic substances in chloroplasts in the light with the release of oxygen. Photosynthesis occurs in 2 phases: light and shadow. The luminous phase occurs in the light. During the light phase, chlorophyll is excited by absorbing a light quantum. In the light phase, photolysis of water occurs, followed by the release of oxygen into the atmosphere. In addition, the following processes occur in the light phase of photosynthesis: accumulation of hydrogen protons, synthesis of ATP from ADP, addition of H+ to a special NADP carrier

RESULT OF LIGHT REACTION:

Formation of ATP and NADP*H, release of O2 into the atmosphere.

Dark phase(CO2 fixation cycle, Calvin cycle) occurs in the stroma of the chloroplast. The following processes occur in the dark phase

ATP and NADP*H are taken from the light reaction

From the atmosphere - CO2

1) CO2 fixation

2)Glucose formation

3) Starch formation

FINAL EQUATION:

6CO2+6H2O---(chlorophyll, light)-C6H12O6+6O2

Chemosynthesis is the synthesis of organic substances using the energy of chemical reactions. Chemosynthesis is carried out by bacteria. The main reactions of photosynthesis are: 1) sulfur oxidation: 2H2S + O2 = 2H20 + 2S

2S + O2 + 2H2O = 2H2SO4 2) nitrogen oxidation: 2NH3 + 3O2 = 2HNO2 + 2H2O 2HNO2 + O2 = HNO3 3) oxygen oxidation 2H2 + O2 = 2H2O 4) iron oxidation: 4FeCO3 + O2 + 6H2O = 4Fe(OH)3 + 4CO2

20. Metabolism in the cell. The process of dissimilation. The main stages of energy metabolism. Metabolism is a unity of assimilation and dissimilation. upon dissimilation, they also undergo further transformations. Assimilation is the process of assimilation of substances entering a cell to specific substances characteristic of a given cell. Assimilation is an endothermic process that requires energy. The source of energy is previously synthesized substances that have undergone decay during the process of dissimilation. Dissimilation is an exothermic process, i.e. the process of releasing energy due to the breakdown of cell substances. Substances formed All functions performed by a cell require energy, which is released during the process of dissimilation. The biological significance of dissimilation comes down not only to the release of energy required by the cell, but often to the destruction of substances harmful to the body. The entire process of dissimilation, or energy metabolism, consists of 3 stages: preparatory, oxygen-free and oxygen. In the preparatory stage, under the action of enzymes, polymers are broken down into monomers. Thus, proteins are broken down into amino acids, polysaccharides into monosaccharides, fats into glycerol and fatty acids. During the preparatory stage, little energy is released and is usually dissipated in the form of heat. 2) Anoxic or anaerobic stage. Let's look at the example of glucose. In the anaerobic stage, glucose decomposes to lactic acid: C6H12O6 + 2ADP + H3PO4 = 2C3H6O3 + 2H2O + 2ATP (lactic acid) 3) Oxygen stage. During the oxygen stage, substances are oxidized to CO2 and H2O. With the access of oxygen, pyruvic acid penetrates into the mitochondria and undergoes oxidation: C3H6O3+6O2-6CO2+6H2O+36ATP Total equation: C6H12O6+6O2-6CO2+6H2O+38ATP

DISSIMILIATION AND ASSIMILATION

(from the Latin dissimilis - dissimilar and assimilis - similar) - mutually opposite processes that ensure the continuous functioning of living organisms in unity; occur in the body continuously, simultaneously, in close interrelation and constitute two sides of a single metabolic process. D. and A. form a complex system consisting of a chain of interconnected biochemicals. reactions, each of which individually is only chemical, but which in unity constitute a biological reaction.

D i s i m i l i c i a t i o n - the process of breakdown in a living organism of organic matter. substances into simpler compounds - leads to the release of energy necessary for all vital processes of the body. A s i m i l i c i a - the process of assimilation of organic. substances entering into, and assimilating them to organic. substances characteristic of a given organism occurs using energy released during dissimilation processes. In this case, compounds with high energy (macroergic) are formed (synthesized), which become a source of energy released during dissimilation.

Dissimilation of nutrients entering the body, mainly proteins, fats and carbohydrates, begins with their enzymatic breakdown into simpler compounds - intermediate metabolic products (peptides, amino acids, glycerol, fatty acids, monosaccharides), from which the body synthesizes (assimilates) ) organic connections necessary for its life. All processes D. and a. occur in the body as a whole. See Metabolism, Life and lit. with these articles.

I. Weisfeld. Moscow.

Philosophical Encyclopedia. In 5 volumes - M.: Soviet Encyclopedia. Edited by F. V. Konstantinov. 1960-1970 .

See what “DISSIMILATION AND ASSIMILATION” is in other dictionaries:

- (Latin assimilatio, from assimilare to liken). Equation, likening, for example, in phonetics, likening neighboring sounds to one another; in physiology, the likening of substances absorbed by an animal to the substances of one’s own body. Dictionary of foreign words,... ...

- [lat. dissimilatio dissimilarity] linguistic. a change that destroys the likeness and similarity of sounds in a word. Dictionary of foreign words. Komlev N.G., 2006. dissimilation (lat. dissimilatio dissimilarity) 1) otherwise catabolism is the breakdown of complex organic... ... Dictionary of foreign words of the Russian language

Assimilation- (from Lat. assimilatio reproduction), anabolism, a process during which more complex ones are synthesized from simpler substances (polysaccharides, nucleic acids, proteins, etc.), similar to the components of this organism and necessary for it... ... Ecological dictionary

The term assimilation (lat. assimilatio assimilation) is used in several fields of knowledge: Assimilation (biology) is a set of synthesis processes in a living organism. Assimilation (linguistics) assimilation of the articulation of one ... Wikipedia

- (lat. dissimilatio dissimilarity). Replacing one of two identical or similar sounds with another, less similar in terms of articulation to the one that remained unchanged. Like assimilation, dissimilation can be progressive or regressive.… …

I A change that violates the similarity, the similarity of the same or similar sounds in a word or in neighboring words; dissimilarity (in linguistics). Ant: assimilation I II f. Disintegration in the body of complex organic substances, cells, tissues, etc. (in biology) ... Modern explanatory dictionary of the Russian language by Efremova

- (lat. assimilatio assimilation). The likening of one sound to another in articulatory and acoustic terms (cf.: dissimilation). Assimilation occurs between vowels and vowels, between consonants and consonants... Dictionary of linguistic terms

I Assimilation (from Latin assimilatio) assimilation, fusion, assimilation. II Assimilation (ethnographic) the merging of one people with another with the loss of one of them of its language, culture, and national identity. In many countries in... ...

I Dissimilation (from Latin dissimilis dissimilar) in biology, the opposite side of assimilation (See Assimilation) side of metabolism (See Metabolism), which consists in the destruction of organic compounds with the transformation of proteins, nucleic acids ... ... Great Soviet Encyclopedia

Topic: Assimilation and dissimilation. Metabolism. Purpose of the lesson: To introduce students to the concept of “metabolism in the body”, assimilation, dissimilation, metabolism. Lesson objectives: Educational: to concretize knowledge about metabolism (metabolism) as a property of living organisms, to introduce the two sides of exchange, to identify general patterns of metabolism; establish a connection between plastic and energy exchange at different levels of organization of living things and their connection with the environment. Developmental: to develop the ability to highlight the essence of the process in the material being studied; generalize and compare, draw conclusions; work with text, diagrams, and other sources; realization of students' creative potential, development of independence. Educational: using acquired knowledge, understand the prospects for the practical use of photosynthesis; understand the influence of metabolism on maintaining and promoting health. Equipment: computer, projector, presentation. Lesson type: learning new material. Forms of student work: independent work with a textbook, individual work at the board, frontal work.

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LESSON PLAN

Subject: Assimilation and dissimilation. Metabolism.

The purpose of the lesson:

Introduce students to the concept of “metabolism in the body”, assimilation, dissimilation, metabolism.

Lesson objectives:

Educational: to concretize knowledge about metabolism (metabolism) as a property of living organisms, to introduce the two sides of metabolism, to identify general patterns of metabolism; establish a connection between plastic and energy exchange at different levels of organization of living things and their connection with the environment.

Developmental: to develop the ability to highlight the essence of the process in the material being studied; generalize and compare, draw conclusions; work with text, diagrams, and other sources;

realization of students' creative potential, development of independence.

Educational: using acquired knowledge, understand the prospects for the practical use of photosynthesis; understand the influence of metabolism on maintaining and promoting health.

Equipment: computer, projector, presentation.

Lesson type: learning new material.

Forms of student work:independent work with a textbook, individual work at the board, frontal work.

During the classes

Organizing time.

II. Repetition of material

Checking the correctness of filling out the table “Comparison of the structure of eukaryotic and prokaryotic cells.” (Student’s answer at the board.)
Frontal conversation on the following issues:

What role does the spore play in prokaryotes? How is it different from eukaryotic spores?
Comparing the structure and vital processes of eukaryotes and prokaryotes, highlight features that allow you to assume which cells are historically more ancient and which are younger.
What are enzymes? What is their role in the body?
What is metabolism? Give examples of metabolism in the body.

III. Learning new material.

Assignment: compare two definitions, find whether they are different or similar. How can you explain this?

Metabolism consists of two interrelated processes - anabolism and catabolism.

1. During assimilation, complex molecules are biosynthesized from simple precursor molecules or from molecules of substances received from the external environment.

2. The most important assimilation processes are the synthesis of proteins and nucleic acids (common to all organisms) and the synthesis of carbohydrates (only in plants, some bacteria and cyanobacteria).

3. During the process of assimilation during the formation of complex molecules, energy is accumulated, mainly in the form of chemical bonds.

1. When chemical bonds in molecules of organic compounds are broken, energy is released and stored in the form of ATP.

2. ATP synthesis in eukaryotes occurs in mitochondria and chloroplasts, and in prokaryotes - in the cytoplasm, on membrane structures.

3. Dissimilation provides all biochemical processes in the cell with energy.

All living cells constantly need energy to carry out various biological and chemical reactions within them. Some organisms use the energy of sunlight (during photosynthesis) for these reactions, while others use the energy of chemical bonds of organic substances supplied with food. Energy is extracted from food substances in the cell by their breakdown and oxidation by oxygen supplied during respiration. Therefore this process is calledbiological oxidation, or cellular respiration.

Biological oxidation involving oxygen is called aerobic , without oxygen – anaerobic . The process of biological oxidation occurs in a multi-stage process. At the same time, energy accumulates in the cell in the form of ATP molecules and other organic compounds.

IV. Consolidation of the studied material.

What is assimilation? Give examples of synthesis reactions in a cell.
What is dissimilation? Give examples of decay reactions in a cell.
Prove that assimilation and dissimilation are two sides of a single process of metabolism and energy - metabolism.

Exercise. Establish a correspondence between the processes occurring in the cells of organisms and their belonging to assimilation or dissimilation:

Processes occurring in cells

Metabolism

1. Water evaporation

Under the influence of biological catalysts (enzymes) from compounds (food components) entering the body, new substances are formed from which its cells are built. This is how the process works assimilation(anabolism) - the assimilation of substances necessary for the body and their transformation into compounds similar to the components of this organism and necessary for its life.

Simultaneously with the process of assimilation in the body, the process dissimilation(catabolism), in which complex organic compounds formed and accumulated during assimilation are also enzymatically decomposed into simpler compounds or final products with the gradual release of energy, most often in the form of ATP, which is used for a variety of life processes, including the synthesis of new compounds.

Assimilation and dissimilation, although processes that are opposite in results, are fundamentally closely interrelated and interdependent. Their relationship is revealed in the expenditure on the biosynthesis of substances (assimilation) of the energy that is released in the process of dissimilation. Without this energy, the breakdown products of proteins, fats and carbohydrates necessary for biosynthesis cannot be formed. On the other hand, assimilation causes the accumulation of the corresponding energy material in the body. These processes are the most important links metabolism- a set of processes of biochemical transformations of substances and energy in living organisms, metabolism.

Assimilation is also called the exchange of plastic nutrients, and dissimilation is also called energy metabolism. For assimilation, green plants use the energy of absorbed light rays, while chemosynthetic microorganisms use the energy released during the oxidation of various inorganic substances.

ATP is a universal source of energy in the cell. In the human body, animals, most microorganisms, the necessary energy is generated in catabolic reactions during respiration or fermentation. This energy, before being transformed into some other form (mechanical, osmotic), transforms into a special form of chemical energy - the energy of high-energy bonds of adenosine triphosphoric acid molecules. In most organisms, the energy released during one enzymatic reaction is part of a “catalytic conveyor” - a cascade process of energy release. The accumulation and transport of energy is carried out using one and universal source of energy for the functional activity of the cell for all organisms - ATP.

The main substances from which the cell draws energy in ATP are widespread monosaccharides, primarily glucose. Among the many ways of glucose breakdown, two closely related processes based on the anaerobic breakdown of the substrate play an important role - glycolysis and different types of fermentation of glycolysis products.