Biological system: what it is, characteristics and components.

A summary about the concept of biological system, and what is the purpose of researching about them.

From a biological point of view, life refers to that which distinguishes animals, plants, fungi, protists, archaea and bacteria from the rest of natural realities.

Life implies the capacities of living beings to organize themselves at the tissue level, to grow, to metabolize substances, to respond to external stimuli to a greater or lesser extent, to reproduce (sexually or asexually) and to die.

Experiments such as that of Miller and his primordial soup have brought us closer to the conception of life, since it was possible to synthesize various organic molecules from inorganic materials, which correspond to the bases of the cells that give rise to all living beings on the planet. Even so, the emergence of "being" from "non-being" remains an unknown, since producing living beings from material that has never been living continues to be a biological impossibility.

These data put into perspective the intricate complexity of all living things, from the most basic unicellular bacterium to the human being and all the organs with specialized cells that comprise it. To understand the particularities of each biological taxon and how it functions, we have to turn to the definition of the biological system and the interactions between those that make us up. Today we tell you all about this exciting and little-known term.

What is a biological system?

Although it sounds redundant, the only possible definition that adequately describes the term that concerns us today is "a complex network of biologically relevant entities"..

On the other hand, the Royal Academy of Engineering describes a biological system as a set of relevant organs and structures that work together to fulfill some physiological function in a living being, such as the Cardiovascular system, the circulatory system, the arterial system, the adrenal system and many others. This last meaning may be valid, but it leaves several very interesting concepts by the wayside.

A biological system, on the other hand, should in no case be confused with a living system/organism per se.. The set of systems allows life, but a system per se is not alive.

The basic biological system: the cell

When approaching this term, many informative sources resort directly to the concepts that best fit a system: the digestive system, for example, which is composed of a series of organs and ducts that allow us to ingest, metabolize and excrete food remains. Even so, we cannot forget that absolutely all living beings on this planet are composed of a biological system on a microscopic scale: the cell.

Thus, a narrow definition of the cell is the morphological and functional unit of every living being. It is a complex thermodynamic biological system, since it possesses all the characteristics to maintain itself over time (if we are not talking about specializations). For a cell to be considered as such, it must meet the following requirements:

• Individuality: all cells are surrounded by a membrane or membranes that distinguish them from the medium, but have pores that enable exchange.
• Aqueous medium: the cytosol, the intracellular fluid in which the organelles essential for cell metabolism float.
• DNA genetic material: the key to heredity and protein formation, i.e. to life itself at the physiological and structural level.
• Proteins, enzymes and other biomolecules that enable active metabolism.
• Capacity for nutrition, growth, differentiation, signaling and evolution.

As you can see, a cell is a biological system if we look at the first definition given: a complex network of biologically relevant entities.. In this case, we conceive as an "entity" each of the organelles, the genetic information, the cytosol and the membranes that delimit their spaces, which are interconnected to give rise to a "larger entity", in this case, the basic structure for life.

Moving up the evolutionary scale: other biological systems

While the cell is the most basic biological system we can describe, one of the miracles of life is the cell, one of the miracles of life is the association of a group of cells according to specialized functions.. This is how we came to be eukaryotic living beings, those of us who possess more than a single cell in our body, unlike bacteria, archaea and protozoa, for example.

At this point we speak of organ and tissue systems, understanding as "organ" an association of various tissues of cellular origin that form a structural unit responsible for the fulfillment of a specific function within a multicellular organism. Thus, these structures are one rung above the tissue, but one below the typical biological system.

What can we say here that every reader does not already know? The respiratory system, the digestive system, the cardiovascular system, the urinary system, the endocrine system, all comprise a network of ducts and organs.all of them comprise a network of ducts and organs specialized in a series of specific functions and, therefore, are conceived as typical biological systems.

The last step: the biological network at the ecosystemic level.

As you can imagine, a biological network is a system based on subunits connected to each other within a whole.For example, the trophic webs in an ecosystem. Each of the living beings (entities) that make up a food web are composed of multiple biological systems but, in turn, they are only a small point in the largest biological system of all: the one that allows the flow of energy and the permanence of the ecosystems that make up our planet.

Not everything is about predation, because there are also biological networks based on intra- and interspecific competition without the need for the death of living beings, for example, the indirect struggle for a resource or for the search for a mate. An ecosystem is like a tower made of metal: if one of the fundamental pillars is removed, everything on top collapses.

It is also necessary to point out that, although we have given you the most typical example of all, a biological network does not only apply to ecosystems and the interactions between living beings.. For example, a metabolic network is also a biological network according to the definition given, although on a much smaller scale than the one mentioned above. In this case, each of the interconnected "points" are chemical compounds, which are "linked" by chemical reactions that give rise to one substance or another through the use of enzymes.

Neural networks, gene regulatory networks and networks formed by the interaction between proteins, for example, are also biological networks. After all, we are talking about biologically interconnected entities at all times on a larger or smaller scale, aren't we?

The use of biological systems

Not everything remains on paper, since the description of a biological system or a network provides us with a wealth of information that is essential for resolving doubts, climatic issues and even pathologies. This is an exciting field at the interdisciplinary level, since the cellular metabolism of a living being (cellular system) and its capacity for growth and development (organ system) will largely condition the amount of biomass it contributes to an ecosystem (biological network/trophic web, for example). it contributes to an ecosystem (biological network/trophic web), for example. In other words, everything is interconnected.

Thus, certain experiments are based on mathematical modeling and simulation software, which, from the databases generated by certain technologies, can establish predictive computational models of biological systems. Describing a network of interconnected entities enables us to predict how they will behave in a given scenario and, undoubtedly, this is vital for understanding the past, present and future of human society at the climatic and pathological levels, among many other things.

The integration and correlation of the data provided by each of the systems is no longer limited to human subjectivity and understanding, as this computer modeling is the key to many more processes than we might at first imagine.

Summary

Unwittingly, we have made a journey through life itself, from the first spark of being, the cell, to the network of interconnected biological systems that allows us to be in three-dimensional space surrounded by life, i.e., the ecosystems that make up our own planet.

Biological systems are energy, complexity, interaction, but above all adjectives, they are one thing: the explanation of life itself. From the smallest cell to the magnitude of a planet itself, everything is interconnected.

Bibliographical references:

• Biological system, biologyonline.com. Recogido a 20 de diciembre en https://www.biologyonline.com/dictionary/biological-system
• Biological system, longdom.org. Recogido a 20 de diciembre en https://www.longdom.org/scholarly/biological-systems-journals-articles-ppts-list-587.html
• Camazine, S., Deneubourg, J. L., Franks, N. R., Sneyd, J., Bonabeau, E., & Theraula, G. (2003). Self-organization in biological systems. Princeton university press.
• Edelman, G. M., & Gally, J. A. (2001). Degeneracy and complexity in biological systems. Proceedings of the National Academy of Sciences, 98(24), 13763-13768.
• Haefner, J. W. (2005). Modeling Biological Systems:: Principles and Applications. Springer Science & Business Media.
• La Biología de Sistemas por el Prof. Dr. D. José Luis Iborra Pastor, académico honorario, Academia de Ciencias de la Región de Murcia. Recogido a 20 de diciembre en https://www.um.es/acc/la-biologia-de-sistemas/