What is the metabolism?

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

1. What is the metabolism?

The set of controlled chemical reactions by which living beings can change the nature of certain substances to obtain the nutritional elements and the amounts of energy required by the processes of growth, development, reproduction and support of life is called metabolism.

The 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 favorable chemical reactions to the organism , while also stopping unfavorable ones, through specific chains of reactions called metabolic pathways, in which a substance is transformed into a chemical that in turn fuels a new process. of transformation, separating the compounds that the metabolism considers nutritious, from those that it considers toxic and should be discarded.

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

2. Phases of metabolism

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

• Catabolism or destructive metabolism. Energy-releasing processes from the breakdown of chemical bonds present in nutrients, usually through degradation and oxidation , converting 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 components necessary for anabolism.
• Anabolism or constructive metabolism. Construction processes that consume chemical energy , to undertake the reverse process to catabolism, thus forming more complex molecules from simple structures , and supplying the body with proteins , lipids , polysaccharides or nucleic acids.

3. Metabolism functions

The 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 , the metabolism serves to fix the carbon and from simple molecules, using sunlight or chemical energy from external sources, synthesizing the sugars that will then serve as cellular fuel.

In contrast, in heterotrophic organisms such as animals , the metabolism starts from oxidizing and breaking down glucose (glycolysis) extracted from the organic matter from which they feed, which requires a digestion that transforms the tissue and the matter consumed in their elementary components

4. Importance of metabolism

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

If the metabolism stopped, death would ensue , as it would be impossible to continue obtaining chemical energy to sustain vital activity, much less to grow or to reproduce or replace damaged tissues.

5. 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 exhibit a predilection for diets rich in animal proteins and fats, and are often hungry frequently. Carbohydrates are not good for you.
• Carbohydrate metabolism. The opposite side of the coin, are people of moderate appetite who prefer sweets and flours, as well as stimulants (such as coffee), and have a frequent variation in weight , costing them to achieve some stability.
• Mixed metabolism. An intermediate category between protein and carbohydrates, it is nourished equally in both ways and is usually maintained in moderate hunger margins. However, when the feeding fails, they are the first group to give symptoms of fatigue.