Contents
Characteristics of proteins
The word protein comes from the Greek “proteios” which means fundamental. This word indicates the importance of these components have in the body. In fact, proteins are the most important component of the body after water.
Proteins are the structural elements of our body. They are the stuff of which tissues are formed. They can be considered the “bricks” that make up the muscles, bones, ligaments, nails, hair and other parts of our body.
In addition, other proteins are also functional elements, for example, hormones or enzymes responsible for metabolic reactions, antibodies and blood hemoglobin are also made of proteins
What are proteins made of?
Proteins are made up of basic units called amino acids.
There are nine amino acids that are called essential because the body can not produce by itself. The remaining amino acids are called nonessential because the body can synthesize them from others.
The liver is the organ capable of producing nonessential amino acids, from other amino acids ingested through our diet, depending on the needs our body has.
The following table shows the amino acids in proteins:
List of amino acids in food | |
Essential amino acids | Nonessential amino acids |
Phenylalanine, Isoleucine, Leucine, Lysine, Methionine, Threonine, Tryptophan, Valine | Aspartic acid, Glutaminic acid, Alanine, Arginine, Cysteine, Cystine, Glycine, Hydroxyproline, Proline, Serine, Tyrosine |
Histidine is an essential amino acid in children because they do not have the ability to produce it because they lack the necessary hormones to do so.
Why do we need protein?
We need proteins especially while we are in our mother’s womb or while we are growing because both are special moments in which our body is developing or increasing its tissues.
However, throughout our life, we also need protein because our body’s cells are always regenerating and because the metabolic processes carried out by proteins are constant.
Since we can not, like the rest of the animals, manufacture our own proteins, we are forced to ingest them from food.
Protein intake from food should be constant because the body can not store them. If they are not ingested, the body absorbs those of the muscles, in their destruction.
Protein quality
The ability to assimilate protein from food determines the quality of proteins. Animal proteins are better assimilated than vegetable ones. In this sense it is said that animal proteins are complete proteins.
To assimilate plant proteins we must know how to combine different kinds of food. An appropriate mix of proteins ensures that deficiencies of proteins of some foods can be balanced with the huge amounts in others.
How much protein do we need?
A varied diet, including animal protein, conveys no risk of protein deficiency. Quite the contrary, the diet of Western society usually has too much animal protein, which can cause a potential health risk.
However, those who lead a vegan diet should control the protein intake in order non to present problems of malnutrition
More information on proteins
