Proteins: What They Are and How They Influence the Functioning of the Body

Proteins are biomolecules made up mainly of carbon, hydrogen, oxygen and nitrogen These are not its only components, since certain protein structures can contain sulfur, phosphorus, iron, magnesium, copper and other chemical elements.

From a physiological point of view, proteins are the main components of the cell, which is why they are needed for tissue repair, growth, cell division and many other functions related to the physical structure of living beings.

For this reason, it is not surprising that 10 to 15% of any human being’s diet should be made up of proteins. Luckily, these macromolecules essential for life are found in multiple foods: salmon, eggs, milk, legumes, beef and a long list of foods.

Due to the physical and nutritional importance of these biomolecules, we find it necessary to investigate the morphology, properties and necessary intake of proteins Continue with us on this journey through various biochemical concepts, as we assure you that some of the data in the following lines will surprise you.

What are the characteristics of proteins?

To whet your appetite, we are going to present you with a series of data that frames the world of proteins on a more tangible and objective level. Let’s go there:

As we can see, proteins are governed by a universal language (the genetic code) and they make up the different structures of all the living beings that surround us Even so, we have introduced a term that we have to explain in depth, since the protein structure cannot be understood without it: we have to talk about the amino acid.

Amino acids and their importance

An amino acid is defined as each of the basic units that make up proteins Its chemical structure is based on a central carbon molecule, an amino group, a carboxyl group, a hydrogen atom and a variable chemical radical. Thus, we are faced with a kind of chemical “cross” with a tetrahedral structure in the three-dimensional plane.

There are 20 different amino acids, which are joined in different orders through peptide bonds to give rise to proteins (polypeptide chains) present in nature. Summarizing this terminological conglomerate in a basic simile, it is as if we used the same pieces of a puzzle to create a different painting each time: the results are very different from each other due to the order of the individual components, but the underlying material is the same. In this case, it is clear that the order does alter the product.

We can distinguish two types of amino acids: essential and non-essential The essential ones are those that cannot be synthesized by the body and therefore must be ingested through the diet. It should be noted that the “essentiality” of each of them depends on the taxon of living beings we focus on, since the different metabolic routes of the species mean that some need certain compounds that others do not.

On the other hand, we have non-essential amino acids, those that we can synthesize within our body (mainly in the liver) from intermediates by transamination, and which are therefore not strictly necessary in the diet. Lastly are the conditionally essential amino acids, that is, those that are required in daily intake in certain specific frameworks and situations.

Finally, and after this brief review of the world of amino acids, it is necessary to emphasize that The nutritional quality of a protein is encoded by the number of essential amino acids that are present in its chemical structure in addition to the digestibility of its components and the proportion retained by the body.

protein structure

Describing the structural complexity of proteins as we have done with amino acids is a practically impossible task, since the writing space is finite and there is a lot of ground to cover. It is enough to know that all proteins They have the same central chemical skeleton, that is, a linear chain of various amino acids This is called “primary structure”, and it is what mainly determines the nature and function of the protein in the organism.

Things get much more complicated, because due to the folding of the macromolecule, its three-dimensional arrangement and many other factors, proteins also have a tertiary, secondary and quaternary structure.

Features

All proteins perform essential functions for cellular development and maintenance but we can combine the tasks of these biomolecules in the following points:

We could continue listing functions for days, since some proteins (by themselves or associated with other compounds) They are transporters of substances through the bloodstream, they have motor functions, they give color to living beings, they are an energy reserve and many more functionalities In summary: practically all biological processes require the presence of proteins.

Proteins and nutrition

The World Health Organization (WHO) and the Food and Agriculture Organization of the United Nations (FAO) indicate that 10 to 15% of an individual’s daily energy needs must come directly from proteins This value varies depending on the needs and requirements of the person in question, for example, an athlete with high muscle development may need to increase this intake to 35%.

But be careful: medical organizations such as the Mayo Clinic warn us that consuming more than two grams of protein per kilo of an individual’s weight begins to be excessive, which can translate into long-term liver and kidney problems. In any case, this type of pathology should not worry the general population, since consuming such a high percentage of protein is practically impossible unless supplements are used.

Contrary to what certain sectors of the population believe, Not only meat and animal products contain protein For example, 100 grams of lentils have 9 grams of pure protein. It is true that meat has a higher proportion (25 grams per 100 grams of fillet), but it is possible to obtain all the necessary protein intake without resorting to meat products.

Protein is present in a wide range of foods, whether of animal or plant origin: fish, red meat, chicken, turkey, eggs, milk, nuts, soy, oats and many other foods. So that, The source of obtaining and the modulation of the diet based on protein intake depends completely on the values ​​and needs of each person

Summary

As we have seen, there is enough information available about proteins to write several books. From a biological point of view, they represent the majority of the organic components of the tissues of living beings and fulfill a series of countless functions in our body. They also have a characteristic structure based on amino acids, universal compounds that encode their functionality and nature according to the arrangement they present in the linear chain.

Finally, we have also shown you the importance of protein intake in the human diet and what foods are rich in it. Of course, we are dealing with a biomolecule and macronutrient (along with fats and carbohydrates) without which we could not live.