Metabolism in living beings. What is “metabolism” (metabolism) and why is it important to define it? Definition of the word metabolism in biology

Metabolism is a set of chemical transformations occurring in living organisms that ensure their growth, development and vital processes.
Nutrition is the maintenance of human life and health with the help of food, to maintain the normal course of physiological processes of life, health and performance.
Respiration is a set of processes that ensure the supply of oxygen to the body from atmospheric air, its use in the biological oxidation of organic substances and the removal of carbon dioxide from the body.
Movement is the process of changing the position of the body and its parts.
Irritability is the property of living organisms to respond to various influences.
Reproduction is the ability of living organisms to reproduce their own kind in order to prolong the race.
Growth is an increase in the mass of an organism, organ or tissue area due to an increase in the number and size of cells and non-cellular formations.
Organic substances are substances that are part of living organisms and are formed only with their participation.
Proteins are high-molecular organic substances consisting of amino acids connected in a chain by peptide bonds.
Fats are mixtures of esters formed by the trihydric alcohol glycerol and higher fatty acids.
Carbohydrates are a large group of organic compounds that are part of all living organisms.
Nucleic acids are compounds consisting of phosphoric acid residues, purine and pyrimidine bases and carbohydrates.
Nitrogen is an essential component of proteins and nucleic acids.
Oxygen is a vital element with which organisms breathe.
The membrane is the membrane of the cell.
A chromosome is a thread-like structure in the cell nucleus that carries genetic information in the form of genes, which becomes visible when the cell divides.
A chromatid is a structural element of a chromosome that is formed in the interphase of the cell nucleus as a result of chromosome doubling.
Mitosis is indirect division, the main method of division of eukaryotic cells.
Meiosis is a special method of division of eukaryotic cells, as a result of which the cells transition from a diploid state to a haploid state.
Tissue is a system of cells and intercellular substance, united by a common origin, structure and functions.
Intercellular substance is a component of the connective tissue of vertebrates and many invertebrate animals, including connective tissue fibers and amorphous ground substance, which performs mechanical, supporting, protective and trophic functions.
An organ is a part of the body, which is an evolutionarily developed complex of tissues, united by a common function, structural organization and development.
A shoot is one of the main vegetative organs of higher plants, consisting of a stem with leaves and buds located on it.
The root is one of the main organs of plants, serving to strengthen the soil, absorb water, minerals, synthesize organic compounds, and also to release certain metabolic products.
A leaf is an important plant organ in which photosynthesis, gas exchange and evaporation occur.
A stem is an elongated shoot of higher plants that serves as a mechanical axis and also serves as a conducting and supporting base for leaves, buds, and flowers.
A flower is the reproductive organ of angiosperms (flowering) plants.
The fruit is a flower modified during the process of double fertilization.
A seed is a special multicellular structure of complex structure that serves for the reproduction and dispersal of seed plants.
The ovary is the lower expanded part of the pistil in a flower, which after pollination forms the fruit.
The stamen is the reproductive organ of an angiosperm flower, in which pollen grains are formed.
Pollen is a collection of pollen grains from seed plants.
An embryo is what an organism is at an early stage of its development.
Endosperm is the storage tissue of plant seeds in which nutrients are deposited.
Hormone is a group of biologically active substances secreted by the endocrine glands

A prerequisite for the existence of any living organism is the constant intake and excretion of final decay products.

What is metabolism in biology

Metabolism, or metabolism, is a special set of chemical reactions that occur in any living organism to maintain its activity and life. Such reactions give the body the opportunity to develop, grow and reproduce, 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. In the second, along with energy expenditure, 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 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 metabolism is in biology is described in detail in this article. All living organisms existing on planet Earth can be divided into eight groups, guided by the source of carbon, energy and oxidizable substrate.

Living organisms can use the energy of chemical reactions or light as a food source. The oxidizable substrate can be either organic or the source of carbon is carbon dioxide or organic matter.

There are microorganisms that, being in different living conditions, use different types of metabolism. It depends on humidity, lighting and other factors.

They can be characterized by the fact that the same organism can have cells with different types of metabolic processes.

Catabolism

Biology considers metabolism and energy through such a concept as “catabolism”. This term is used to describe the process 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, converting it into an accessible form.

In organisms that live thanks to photosynthesis (cyanobacteria and plants), the electron transfer reaction does not release energy, but accumulates it thanks to sunlight.

In animals, catabolic reactions are associated with the breakdown of complex elements into simpler ones. Such substances are nitrates and oxygen.

Catabolism in animals is divided into three stages:

1. Breaking down complex substances into simpler ones.
2. Breaking down simple molecules into even simpler ones.
3. Release of energy.

Anabolism

Metabolism (8th grade biology examines 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 successively formed from the simplest precursors.

First, amino acids, nucleotides and monosaccharides are synthesized. The above elements then become active forms thanks 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 get energy from alternative sources.

Energy obtained from sunlight

What is metabolism in biology? The process through which all life on Earth exists and distinguishes living organisms from inanimate matter.

Some protozoa, plants and cyanobacteria feed on the energy of sunlight. In these representatives, 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. The digestion process involves special enzymes that 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 thanks to extracellular enzymes enter the body using “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 cells, all metabolic reactions must be correctly and accurately regulated. A good metabolism allows 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 essence of this concept and describe examples that will help increase the depth of knowledge.

The first controlled experiment to study metabolism was obtained 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 initial studies, metabolic reactions were not detected, and scientists believed that living tissue was controlled by a living force.

In the twentieth century, Eduard Buchner introduced the concept of enzymes. From then on, 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

Inorganic substances play a very important role in metabolism. All organic compounds consist of large amounts of phosphorus, oxygen, carbon and nitrogen.

Most inorganic compounds allow you to control the level of pressure inside 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 microelements are absorbed thanks to transport proteins and are never in a free state.

Metabolism and energy conversion in the body

Metabolism , or metabolism , is a set of biochemical processes and vital processes of the cell. Ensures the existence of living organisms. There are processes of assimilation (anabolism) and dissimilation (catabolism). These processes are different aspects of the single process of metabolism and energy conversion in living organisms.

Assimilation

Assimilation - these are processes associated with the absorption, assimilation and accumulation of chemicals that are used to synthesize compounds necessary for the body.

Plastic exchange

Plastic exchange is a set of synthesis reactions that ensure the renewal of the chemical composition and cell growth.

Dissimilation

Dissimilation - These are processes that are associated with the breakdown of substances.

Energy exchange

Energy exchange is a set of reactions of the splitting of complex compounds with the release of energy. Organisms from the environment absorb energy in certain forms during their life processes. Then they return an equivalent amount in another form.

The processes of assimilation are not always balanced with the processes of dissimilation. The accumulation of substances and growth in developing organisms is ensured by assimilation processes, so they predominate. Dissimilation processes predominate with a lack of nutrients, intense physical work, and aging.

The processes of assimilation and dissimilation are closely related to the types of nutrition of organisms. The main source of energy for living organisms on Earth is sunlight. It indirectly or directly satisfies their energy needs.

Autotrophs

Autotrophs (from Greek autos– himself and trophy– food, nutrition) are organisms capable of synthesizing organic compounds from inorganic ones using a certain type of energy. There are phototrophs and chemotrophs.

Phototrophs

Phototrophs (from Greek photo– light) – organisms that use light energy for the processes of synthesis of organic compounds from inorganic ones. These include some prokaryotes (photosynthetic sulfur bacteria and cyanobacteria) and green plants.

Chemotrophs

Chemotrophs (from Greek hemia– chemistry) the energy of chemical reactions is used to synthesize organic compounds from inorganic ones. These include some prokaryotes (iron bacteria, sulfur bacteria, nitrogen-fixing bacteria, etc.). Autotrophic processes relate more to assimilation processes.

Heterotrophs

Heterotrophs (from Greek heteros– other) are organisms that synthesize their own organic compounds from ready-made organic compounds synthesized by other organisms. These include most prokaryotes, fungi, and animals. For them, the source of energy is organic substances that they receive from food: living organisms, their remains or waste products. The main processes of heterotrophic organisms are breakdown of substances – based on processes of dissimilation.

Energy in biological systems is used to ensure various processes in the body: thermal, mechanical, chemical, electrical, etc. Part of the energy during energy exchange reactions is dissipated in the form of heat, part of it is stored in macroergic chemical bonds of certain organic compounds. A universal such substance is adenosine triphosphoric acid ATP. It is a universal chemical energy accumulator in the cell.

Under the action of the enzyme, one phosphoric acid residue is cleaved off. ATP is then converted into adenosine diphosphate - ADP. This releases about 42 kJ of energy. When two phosphoric acid residues are eliminated, adenosine monophosphate is formed - ATP (84 kJ of energy is released). The AMP molecule may be broken down. Thus, during the breakdown of ATP, a large amount of energy is released, which is used to synthesize compounds necessary for the body, maintain a certain body temperature, etc.

The nature of the high-energy bonds of ATP remains unclear, although they are several times higher in energy intensity than ordinary bonds.

Metabolism is a set of chemical transformations occurring in living organisms that ensure their growth, development, vital processes, reproduction of offspring, and active interaction with the environment.
In all living organisms, from the most primitive to the most complex, such as humans, the basis of life is metabolism and energy. Thanks to it, every organism not only maintains its existence, but develops and grows. Metabolism determines the cyclical nature of life: birth, growth and development, aging and death.

Plastic and energy metabolism

Under plastic exchange understand processes during which new compounds and new structures that are characteristic of a given organism are created in cells. Under energy metabolism understand such energy transformations, during which, as a result of biological oxidation, the energy necessary for the life of cells, tissues and the entire organism as a whole is released.
The result of biological oxidation is the formation of carbon dioxide, ammonia, phosphorus, sodium, and chlorine compounds, which are excreted from the body. This is the final stage of metabolism. It is carried out by the blood, lungs, sweat glands, and urinary organs.

Scientists have long given a precise definition of metabolism. What is metabolism? This is a complex of complex chemical reactions that occur in the body of a person or other living creature and affect its viability, maintenance of vitality, growth, development and reproduction, as well as protection from the negative effects of the environment. Metabolism is a prerequisite for the normal existence of a living organism.

The regular supply of nutrients into cells, as well as the constant removal of final breakdown products resulting from various chemical processes, is the basis of biochemical and energy metabolism. The essence of these phenomena and the result of their impact on a living organism is studied by a science such as biology. What is metabolism, what is the influence of the speed of biochemical and energy processes on changes in the shape and structure of the body, nutrition and lifestyle, as well as adaptability to various conditions of human existence? These are all categories of biological research.

Main types of metabolism

Let's take a closer look at the process itself and its definition. What is metabolism? This is a process that promotes the processing of nutrients supplied from outside (proteins, fats, carbohydrates, vitamins, water and minerals), as a result of which the human body creates its own proteins, carbohydrates and fats. In this case, the products of decay (splitting), in other words, waste, are removed using the excretory system into the external environment. Biologists have identified several main types of metabolic processes.

These are protein, lipid (fat), carbohydrate, salt and water metabolism. A variety of enzymes that participate in the transformation of various nutrients are at the same time a necessary component of digestion. They structure our nutrition. Metabolism is regulated by enzymes in the right direction.

Two important interconnected stages of the metabolic process

How do biochemical transformations occur inside the body? What causes the metabolic rate to fluctuate? In a healthy person, metabolic processes in the body proceed intensively and quickly.

The technology of these chemical reactions includes two parallel, interconnected, continuous stages: dissimilation and assimilation.

Anabolism (assimilation) is a process associated with the formation of necessary compounds, during the synthesis of which energy is absorbed.

Catabolism (dissimilation) is a process that, on the contrary, promotes the breakdown of various substances and, as a result, the release of energy. Oxygen is rightfully considered the main catalyst (accelerator) of this oxidative process.

Factors affecting basal metabolism

Defining what metabolism is, scientists have identified the necessary minimum expenditure of nutritional components and energy to maintain the body's vital functions in ideal comfortable conditions when a person is at rest. The intensity of metabolic processes can be influenced by:

• genetic memory, or heredity;
• a person’s age (because the metabolic rate gradually decreases over the years);
• climatic conditions;
• physical activity or lack thereof;
• human body weight (obese people require more calories to maintain life support).

In search of an answer to the question of what basal metabolism is, or basal metabolism, physiologists suggest taking into account 4 factors: gender, age, height and body weight of a person. On average, the intensity of basal metabolism is 1 kcal per hour per 1 kg of weight. In men, the basal metabolism per day is approximately 1500-1700 kcal. For women, this figure is approximately 1300-1500 kcal. Children's metabolism is generally higher than that of adults, but gradually decreases over the years.

Metabolism and energy balance

Each person has an individual level of metabolism and energy. The intake of energy from the outside along with food and its expenditure on the life support of the body (basic metabolism plus energy expenditure on physical and mental activity) must be balanced. This energy is measured in units of heat - kilocalories. The balance between the amount of energy incoming and expended ensures normal energy balance.

Regulation of metabolic processes

Under the influence of factors affecting the basal metabolism and the difference between calorie intake and expenditure, the intensity of metabolic processes changes. The most important role in regulation at all levels belongs to the nervous system. Changes can occur in the tissues or organs themselves directly, and can also be a consequence of regulating the amount and activity of enzymes and hormones.

Thanks to the feedback principle, our body is able to independently regulate the level of metabolism. For example, when a large amount of glucose enters the blood, energy is released, which increases the secretion of insulin. It inhibits the process of glucose production from glycogen in the liver, which, in turn, leads to a decrease in its concentration in the blood.

What is a metabolic disorder and what are its causes?

Various metabolic disorders can cause severe, sometimes irreversible consequences. Failures in carbohydrate metabolism can provoke the development of diabetes, and improper lipid metabolism can lead to the accumulation of harmful cholesterol, causing vascular and heart diseases. Excess free radicals lead to premature aging and cancer problems. The reasons for such failures can be both internal and external.

What is a metabolic disorder from the inside? These are diverse genetic problems associated with a hereditary factor (mutation of genes encoding the synthesis of enzymes that cause defects in metabolic processes). Other causes may be diseases of the nervous system, endocrine disorders (dysfunction of the thyroid gland, pituitary gland, adrenal glands).

Physiologists include disturbances in the diet (overeating, unbalanced diets, etc.) and ignoring the rules of a healthy lifestyle as external causes. When figuring out what improper metabolism is, it is necessary to remember: there are both individual causes of its occurrence and complex ones, when, along with the disease, a person may have disturbances in the diet, physical inactivity.

Fat metabolism

Lipid (fat) metabolism deserves special discussion. Fats in the human body are the richest source of energy. What is lipid metabolism? The process of lipid oxidation releases more energy than the processing of carbohydrates and proteins combined. In addition to a large amount of energy, the breakdown of fats produces quite a lot of moisture, which supports water metabolism.

Fats in the body are essential nutrients. Individual vitamins dissolve in lipids; they serve as a component of cell membranes, material for the synthesis of certain hormones and enzymes, and participate in neuromuscular transmission. Adipose tissue performs a thermal insulation and protective function, softens and moisturizes the skin. A sufficient and balanced amount of fat in the diet guarantees proper lipid metabolism, health and excellent appearance.

What is fast metabolism, or how to gain weight

How often do people, dissatisfied with their thinness, complain that food does not suit them for future use. They cannot gain optimal weight due to their fast metabolism. An increased metabolic rate is genetically determined in people with an ectomorphic body type. They are characterized by a small amount of subcutaneous fat and a slow rate of muscle growth. What is fast metabolism? This is a high rate of metabolic reactions.

People with this “gift of nature” are rewarded with increased activity, good physical shape and are not susceptible to excess body weight. After 30 years, especially in women, as a result of physical inactivity and poor nutrition, thickening of the subcutaneous fat layer may occur in certain areas of the body. This is partly the result of the fact that every six months from this age, the metabolic rate decreases by 3-4%. But correcting your figure in these cases is very simple: you just need to adhere to a balanced diet and increase physical activity.

How to restore proper metabolism?

Many lovers of strict unbalanced diets that guarantee rapid weight loss soon find themselves in a dilemma. Continuing to reduce the caloric content of their diet, they experience a decrease in metabolic rate, which leads to the fixation of the scales. A calorie deficit no longer leads to weight loss. In this case, nutritionists advise increasing metabolism. What is accelerated metabolism? This is a mandatory morning breakfast, split balanced meals throughout the day, a large amount of water drunk, aerobic and anaerobic training, walks in the fresh air, visits to the sauna and steam bath, sleep lasting at least 8-9 hours. In addition, it is necessary to include in the diet foods that accelerate metabolism: spices (pepper, cinnamon, ginger, mustard), seafood, citrus fruits (grapefruit), ginseng, B vitamins, green tea.

Essentially, what is metabolism ideally? This is a competent ratio of the amount of food consumed and its expenditure. An early breakfast will help the body “wake up” and start the metabolic process, small meals will provide vital substances without hunger and harm to the body, and physical activity will bring the body to the desired shape. Hunger, on the contrary, slows down and stops metabolism, which leads to the cessation of the weight loss process.

Conclusion

Prevention of metabolic disorders consists not only of regular visits to the doctor, but also of a healthy diet, a competent work schedule and adequate rest, compliance with environmental and sanitary standards (where possible), and physical activity. Knowing what metabolism is, you can ensure the flawless functioning of your body and stay healthy for many years!