We explain what metabolism is, what its phases are and the functions it performs. Its importance and types of metabolism.
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 to obtain the nutritional elements and the amounts of energy they require in the processes of growth, development, reproduction, response to stimuli, adaptation and support of life.
metabolism takes place inside the cells of living organisms through a set of organic substances, of a protein nature, called enzymes, which are responsible for promoting certain biochemical reactions.
Enzymes seek to generate chemical reactions favorable to the body and avoid unfavorable ones. They do so through specific chains of reactions called “metabolic routes,” in which a substance is transformed into a chemical product that in turn serves as a reagent in a new transformation process, using nutritional compounds and discarding toxic ones.
Different species of living beings use similar metabolic pathways, although each specific metabolism also determines the amount of food the species needs.
See also: Nutrition
Metabolism phases
Biological metabolism is made up of two conjugated phases or stages: catabolism and anabolism. The first deals with releasing energy, breaking given chemical bonds; the second is to use that energy to form new chemical bonds and compose new organic compounds. These phases depend on each other and feed off each other.
- Catabolism or destructive metabolism . Energy-releasing processes are carried out from the breaking of chemical bonds present in nutrients, usually through hydrolysis and oxidation, which convert complex molecules into simpler ones. In exchange, chemical energy (ATP), reducing power (ability to donate electrons or receive protons from certain molecules) and the components necessary for anabolism are obtained.
- Anabolism or constructive metabolism. Constructive processes that consume chemical energy are carried out to undertake the reverse process of catabolism, and form more complex molecules from simple structures, and supply the body with proteins, lipids, polysaccharides and 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 begins with the fixation of carbon dioxide using sunlight, to then synthesize, from simple molecules, carbohydrates that will serve as cellular fuel.
On the other hand, in heterotrophic organisms (such as animals) the metabolism part of oxidizing and breaking down glucose (glycolysis), proteins and lipids extracted from the organic matter on which they feed, which requires digestion that transforms the tissue and the matter consumed into their elemental components.
Importance of metabolism
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 metabolism were to stop, death would ensue since it would be impossible to continue obtaining the chemical energy to sustain vital activity, much less to grow or reproduce or replace damaged tissues.
Types of human metabolism
According to nutrition and food specialists, three types of human metabolism can be identified:
- protein metabolism. People with this type of metabolism are not very prone to ingesting sugars and sweets, they exhibit a predilection for diets rich in animal proteins and fats, and they tend to be hungry frequently.
- carbohydrate metabolism. People with this type of metabolism have a moderate appetite, and prefer sweets and flours, as well as stimulants (such as coffee). They have frequent weight variations and find it difficult to achieve certain stability.
- Mixed metabolism. People with this type of metabolism are equally nourished in both ways and usually maintain moderate levels of hunger. However, when nutrition fails, they are the first group to show symptoms of fatigue.
Continue with: Biomolecules
References
- “Metabolism” on Wikipedia.
- “What is metabolism and how does it work?” in Life and Health.
- “Introduction to metabolism” (video) in network efficiency.
- “What is Metabolism?” in News Medical Life Sciences.
- “Basics of Metabolism” (video) on Khan Academy.
- “Metabolism” in The Encyclopaedia Britannica.
