Metabolism – Concept, types, phases, functions and importance

We explain what metabolism is, what its phases are and the functions it performs. Its importance and types of metabolism.

The processes of metabolism take place in cells.

What is metabolism?

It is called metabolism to the set of controlled chemical reactions through which living beings can change the nature of certain substances in order to obtain the nutritive elements and the amounts of energy that the processes of growth, development, reproduction and life support require.

Metabolism takes place inside the cells of living organisms, through a set of organic substances responsible for promoting certain reactions, called enzymes. In the case of the human body, these substances are secreted by the liver.

Enzymes seek to generate chemical reactions that are favorable to the body, while tackling the unfavorable ones, through specific chains of reactions called metabolic routes, in which a substance is transformed into a chemical product that in turn feeds a new transformation process, separating the compounds that metabolism considered nutritious, those considered toxic and should be discarded.

Very different species of living things use similar metabolic pathways, although each specific metabolism will also determine the amount of food that species needs.

Phases of metabolism

Metabolism - boy running
Catabolism releases energy by breaking chemical bonds present in nutrients.

Biological metabolism is made up of two phases or conjugated stages, known as catabolism and anabolism. The first deals with releasing energy, breaking given chemical bonds; the second is to use this energy to form new chemical bonds and compose new organic compounds. These phases depend on each other and feed back on each other.

  • Catabolism or destructive metabolism. Energy-releasing processes from the breaking of chemical bonds present in nutrients, usually through degradation and oxidation, turning complex molecules into simpler ones. And obtaining in return chemical energy (ATP), reducing power (ability to donate electrons or receive protons from certain molecules) and the necessary components for anabolism.
  • Anabolism or constructive metabolism. Construction processes that consume chemical energy, to undertake the reverse process of catabolism, thus forming more complex molecules from simple structures, and supplying the body with proteins, lipids, polysaccharides or nucleic acids.

Metabolism functions

Metabolism is the set of chemical transformations that provides the living body with the substances it needs to exist, grow and reproduce. In the case of plants and autotrophic organisms, metabolism serves to fix carbon and from simple molecules, using sunlight or chemical energy from external sources, synthesize sugars that will later serve as cellular fuel.

In contrast, in heterotrophic organisms such as animals, the metabolism part of oxidizing and breaking down glucose (glycolysis) extracted from the organic matter on which they feed, which requires digestion that transforms the tissue and the consumed matter into its elemental components.

Importance of metabolism

If the metabolism were to stop it would be impossible to sustain vital activity.

Metabolism is the guarantee of life. Living beings we are exchanging matter and energy with the environment throughout life, so the metabolism accompanies us from birth to death, acting without any interruption.

If the metabolism were to stop, death would ensueIt would be impossible to continue obtaining the chemical energy to sustain vital activity, much less to grow or to reproduce or replace damaged tissues.

Types of human metabolism

According to nutrition and food specialists, three types of human metabolism can be identified, which are:

  • Protein metabolism. Little given to the intake of sugars and sweets, they show a predilection for diets rich in protein and animal fats, and tend to be hungry frequently. Carbohydrates are not good for them.
  • Carbohydrate metabolism. On the other side of the coin, they are people with a moderate appetite who prefer sweets and flours, as well as stimulants (such as coffee), and who present a frequent variation in weight, making it difficult for them to reach a certain stability.
  • Mixed metabolism. An intermediate category between protein and carbohydrates, it is equally nourished by both forms and is usually kept within moderate ranges of hunger. However, when feeding fails, they are the first group to show symptoms of fatigue.