Metabolism and energy

Metabolism and energy (metabolism) - transformation of matter and energy, underlying the activity of organisms. Getting from the environment of different organic and inorganic substances (mainly food), the body can absorb them, i.e. processes specific for themselves substances. This side of metabolism and energy is designated as assimilation.
The process of destruction of organic substances - dissimilation is the opposite of assimilation side of metabolism and energy. Assimilation and dissimilation is inextricably linked to each other. Growth, development, reproduction is always characterized by a predominance of assimilation, which manifests itself in increasing the total mass of the body, in the formation of new tissues and organs, in their growth and differentiation. In certain pathological conditions, as well as in starvation prevails dissimilation that comes in reducing the mass of the living body.
The intensity of metabolism and energy in General depends on the relationships of an organism with its environment. The higher animals and human metabolism and energy, including the ratio of assimilation and inhibition are regulated by the Central nervous system.
The concept of metabolism and energy includes processing by the body of nutrients and making those substances which are part of the body.
The processes of transformation of the substances in tissues and organs, including the formation and decomposition of intermediate products, called interstitial exchange. The study of the interstitial exchange gives an idea of the sequence of biochemical transformations inside the body, about their localization in certain organs and tissues, about how the different chemical reactions in one metabolism and energy of the entire organism.
The processes of metabolism and energy are divided into anabolic and catabolic. The term " anabolic" refers to the chemical reaction in which simpler substances by interacting with each other, form a more complex, which leads to a new cytoplasm of cells to the total growth of a living organism. Anabolic processes underlie assimilation, catabolic - based degradation. Catabolism is the decomposition of organic matter not only of food, but the tissue that leads to spending cytoplasm of cells. Anabolic and catabolic processes are continuously being in complex dynamic relationship; you cannot separate them from each other. Substances, resulting catabolic processes, not only eliminated from the body in the form of end-products of metabolism, but may be involved in anabolic processes: complex compounds of this split, and their constituent parts, connecting in different combinations, form new substances. Thus, the synthesis of tissue proteins, fats and carbohydrates preceded by the collapse of food proteins, fats and carbohydrates (see Nitrogen metabolism, Fat metabolism and Carbohydrate metabolism).
The most important function of catabolism is the release of energy, concluded in organic compounds entering the body or postpone it as replacement substances. Energy is used to update and rebuild tissues; spent when functioning of organs (for example, muscle work, the transmission of nerve impulses and others); takes in the processes of synthesis of organic compounds, including enzymes, part of it is released as heat.
Catabolic processes, giving energy, are fermentation of plants and microorganisms, glycolysis in animals or oxidation of organic substances to CO2 and H2O, which is common in both animals and plant tissues. If you are subjected to oxidation of carbohydrates, then the absorption of 1 liter of oxygen is released of 5.05 kcal of energy if fats and proteins,respectively 4.7 and 4.8 kcal. Each of these substances corresponds to a certain value of the respiratory exchange ratio (Rq), i.e. the ratio of the amount of CO2, allocated for this period of time, to the amount of oxygen absorbed by the body during this time interval. The oxidation of carbohydrates Rq equal to 1, fat - 0,7, protein - 0,8. Since the breakdown of various nutrients in the body occurs at the same time, the value Rq can vary. The average value Rq for a man is usually in 0,83 - 0,87. Defining Rq empirically, using special tables specify the number of the released energy in calories. Power sharing, thus, can serve as an indicator of the intensity of metabolic processes in the body and is characterized by the value of balance (total) currency.
In clinical practice to compare the intensity of metabolism and energy in different people and identify deviations from the norm initially determine the level of basic currency, i.e. the amount of energy consumed to support life at rest, fasting, which is characterized by the same body considerable persistence.
On the basis of numerous definitions of the main exchange in humans tables of normal values for this indicator, depending on age, sex and total body surface. In these tables, the values of the main exchange are in large calories (kcal) per 1 m2 body surface per 1 hour. In persons of the same sex, height, weight and age, the basal metabolic rate is approximately equal and varies ±10-15%. Environmental factors (climate, temperature, barometric pressure), various forms of employment, occupations by sport, mode, and type of food, functional state of the organism cause it's quite a significant deviation from the norm. Great influence on the main exchange affected by changes in hormonal functions of the body. Especially pronounced effect of the thyroid gland: with its hyperactive main exchange may exceed the normal level of 80%, with hypofunction main exchange may be below the norm by 40%. Loss of function of the anterior lobe of the pituitary or adrenal cortex leads to the decrease of the main exchange. Excitation of the sympathetic nervous system, increased the formation or administration of adrenaline from the outside reinforce the main exchange. In the clinic of the research the main exchange carried out erh, i.e. over a 12-16 hour. after a meal, determining the gas exchange in 10-15 minutes the Temperature from 20 to 22 degrees. The value of the basic currency is accepted to give a percentage deviations from the norm.
Cm. also the biological Oxidation.

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