A prerequisite for the existence of any living organism is the constant supply of nutrients and the elimination of the 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 multiply, while maintaining its structure and responding to environmental stimuli.
Metabolism is usually divided into two stages: catabolism and anabolism. In the first stage, all complex substances break down and become simpler. At the second, nucleic acids, lipids, and proteins are synthesized along with energy costs.
The most important role in the metabolic process 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.
The metabolic chains and components are absolutely identical for many species, which is proof of the unity of origin of all living things. This similarity shows the relatively early appearance of evolution in the history of the development of organisms.
Metabolism classification
What is metabolism in biology, 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 oxidized substrate.
Living organisms can use the energy of chemical reactions or light as a source of nutrition. As an oxidizable substrate can be both organic and inorganic substances. The carbon source is carbon dioxide or organics.
There are microorganisms that, being in different conditions of existence, use different types 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 considers 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 break down. During catabolism, simple molecules appear that are involved in biosynthesis reactions. Thanks to these processes, the body is able to mobilize energy, turning it into an accessible form.
In organisms that live through photosynthesis (cyanobacteria and plants), the electron transfer reaction does not release energy, but accumulates, thanks to sunlight.
In animals, catabolism reactions are associated with the splitting of complex elements to simpler ones. Such substances are nitrates and oxygen.
Catabolism in animals is divided into three stages:
- Splitting complex substances to simpler ones.
- Cleavage of simple molecules to even simpler ones.
- Release of energy.
Anabolism
Metabolism (biology of class 8 considers this concept) is also characterized by anabolism - a set of metabolic processes of biosynthesis with the expenditure of energy. 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 get energy from alternative sources.
Energy derived from sunlight
What is metabolism in biology? The process by which everything living on Earth exists, and distinguishing living organisms from inanimate matter.
The energy of sunlight feeds on some protozoa, plants and cyanobacteria. In these representatives, metabolism occurs due to photosynthesis - the process of oxygen uptake and the release of carbon dioxide.
Digestion
Molecules such as starch, proteins and cellulose are broken down before they are used by the cells. In the digestion process, special enzymes take part, which break down proteins to amino acids, and polysaccharides to 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 through "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 all of them are surrounded by an environment that is constantly changing, in order to maintain optimal conditions inside the cells, all metabolic reactions must be correctly and precisely 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-Nafisa, who believed that the whole body is constantly in a state of nutrition and decay, so 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 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 “invisible evaporation” process.
In the initial studies, metabolic reactions were not detected, and scientists believed that living force controlled living tissue.
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 the body.
Minerals
Inorganic substances play a very large role in metabolism. All organic compounds are composed 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 positively affects 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 are never in a free state.