Amino acids and proteins: the most frequent questions

The word protein comes from the Greek protagonistwhich means “the first”, or of the god Proteus, due to the diverse morphology that they can adopt, having a very important role in the construction of tissues.

The versatility of proteins is enormous because, in addition to helping to create body tissues, they are a structural part of enzymes, antibodies, red blood cells, etc.

Proteins are large molecules (macromolecules)made up of a large number of amino acids, its basic units. A simple protein has hundreds to thousands of amino acids.

When we eat protein-rich foods, they hydrolyze (“break” into units) and form amino acids, of which there are twenty different ones linked together by peptide bonds.

What is protein synthesis and what does it have to do with diet?

Protein synthesis in our body is made from amino acids. and is mediated by the information contained in the genes.

An amino acid is a molecule that contains a free carboxyl group (-COOH) and an amino group (-NH2). The union of several amino acids is what allows to form a protein, and there are approximately 20 different amino acids composing proteins.

Plants have the ability to synthesize amino acids from inorganic chemicals. simple. Animalswho do not have this capacity, obtain all the amino acids necessary to develop their proteins the consumption of plants or animals.

Animals have different abilities to convert one amino acid to another. In humans this capacity is limited. and the conversion is done especially by the liver.

If the ability to convert one amino acid to another were unlimitedthe discussion about the protein content in diets and the prevention of protein deficiency would be a trivial matter. It would only be necessary to supply enough proteinregardless of its quality or amino acid content.

Amino acids that need to be ingested by the body to obtain them and that we cannot create or synthesize ourselves are called essential, and their lack leads to developmental disorders.

Amino acids: types and functions

There are 22 amino acids, although two of them (selenocystine and pyrrolysine) animals do not have them, so we are left with twenty, ten of which are essential and ten non-essential.

essential amino acids

Valine. It is one of the most common amino acids, and therefore its deficiency is rather rare.leucine. It is an amino acid with a nonpolar side chain, an isobutyl (2-methylpropyl) group.Isoleucine. It is one of the most common and with a chemical composition very similar to that of leucine, although with a slightly different arrangement of atoms: its side chain is a sec-butyl (1-methylpropyl) group.phenylalanine. It exists in the form of two enantiomers, the D- and the L-form, depending on its spatial organization. The form found in proteins is L-phenylalanine (LFA), and it is also one of the ten essential amino acids for humans. It is also part of many psychoactive substances and is a precursor to catecholamines such as L-dopa, norepinephrine, and epinephrine, through a stage in which tyrosine is formed. On the other hand, L-phenylalanine is found in the neuropeptide structure such as somatostatin, vasopressin, melanotropin, enkephalin, adrenocorticotropic hormone (ACTH), angiotensin, substance P, and cholecystokinin.

Phenylalanine is found mainly in protein-rich foods such as meat, fish, eggs, and dairy products. It is also a frequent substance (in very small doses) in many of the most commonly used drugs.

methionine. It is one of the essential amino acids that make up the protein synthesis mechanism of living beings. In the form of S-adenosylmethionine (5AM) it is one of the main methylating agents in the body.threonine. It is obtained mainly through a fermentation process by microorganisms (for example, genetically modified yeasts), although it can also be obtained by isolation from protein hydrolysates for pharmaceutical use.lysine. It is synthesized by bacteria and higher plants, through diaminopimelic acid, or by higher fungi, through alpha-aminoadipic acid. It is part of the mechanism of protein synthesis by messenger RNA.tryptophan. It is a neurotransmitter, precursor of serotonin and 5-hydroxytryptamine. Several studies have shown that the concentration of serotonin in the brain is directly proportional to the concentration of tryptophan in the plasma and brain. Tryptophan dietary intake directly influences the amount of serotonin in plasma, brain and whole body levels.
This was the first accepted demonstration -performed in 1980- of the direct dietary control of a brain neurotransmitter through a single amino acid. Tryptophan is the least abundant essential amino acid in food. Ham and meat contain the highest amounts of tryptophan, as well as salted anchovies, drier cheeses and melted cheeses, eggs and almonds.histidine. It is one of the most common amino acids and is considered an essential amino acid, especially in children. It is a precursor of histamine biosynthesis and therefore has to do with the processes of immunity and allergy.arginine. In its left-hand optical isomer (termed L-arginine) it is classified as one of the ten essential amino acids, especially in childhood. It is involved in many of the activities of the endocrine glands.

non-essential amino acids

To the girl. It is the smallest amino acid after glycine.Proline. It is the only alpha-amino acid. It is a molecule that repels water.wisteria. It is a non-essential amino acid, formerly known as glycine, and acts as an inhibitory neurotransmitter in the central nervous system. It was proposed as a neurotransmitter in 1965.Serine. It is one of the three amino acids commonly phosphorylated during cell signaling in eukaryotic organisms.cysteine. It is a non-essential, sulfur-containing amino acid that can be oxidized to cystine, and is formed from methionine by transmethylation and transsulfuration.Asparagine (asparagine or asparagine). It is one of the most common amino acids, and is the amide of aspartic acid. One of its by-products is attributed the characteristic odor of the urine of someone who has eaten asparagus.glutamine. It is one of the common amino acids. It is the most abundant amino acid in human muscles (up to 60%) and is closely related to the metabolism that takes place in the brain. Your supplementation seems reduce oxidative stress of the muscles.tyrosine. It is synthesized by degradation of phenylalanine and has to do with the process of formation of cellular energy, since it acts on a molecule called acetyl-CoA.Aspartic acid (or aspartate). It belongs to the group of amino acids with charged polar side chains and has to do with the Krebs cycle, in which the energy necessary for life is obtained.Glutamic acid. It is not an essential nutrient. It is a neurotransmitter exciting the cerebral cortex human. It plays a central role in relation to transamination processes and in the synthesis of different amino acids that require the prior formation of this acid, such as proline, hydroxyproline, ornithine and arginine, and it accumulates in considerable proportions in the brain. . It is one of the most active amino acids in metabolism and plays a fundamental role in cell growth and maintenance.

7 Amino Acids That Are Taken As Supplements

Certain amino acids fulfill a specific function in the body apart from nutrition, and are increasingly recommended as supplements in certain cases and problems. Let’s see the most common.

Taurine. It strengthens the heart muscle and improves eyesight by preventing macular degeneration. Taurine is also a supplement advertised as a stimulant of physical resistance and sexual vigour, and for this reason it is included in so-called “energy drinks” in doses of 1 to 5 grams per individual drink. Your needs may be somewhat increased in people who do a lot of physical exercise.arginine. It is indicated as a cardiovascular stimulant, of immunity, of sexuality, to gain muscle mass (it is one of the preferred amino acids of bodybuilders) and to accelerate recovery from surgical interventions.tryptophan. It is a neurotransmitter, which also serves for the synthesis of other neurotransmitters, such as serotonin. Its supplementation is recommended in cases of insomnia, depression or lack of encouragement. It is for sale in health food stores.glutamine. Another amino acid that is recommended to athletes and bodybuilders, as it favors the recovery of glycogen in the liver and in the muscle, which gives greater capacity to face intense exercise. It is administered in doses of 3 to 5 grams daily.phenylalanine. It is effective as a treatment for muscle or lower back pain, migraines, menstrual pain, rheumatoid arthritis and osteoarthritis, and in the treatment of depression.methionine. Like all amino acids, it helps to improve muscle mass, although in this case it is also indicated to whet the appetite and to reduce the harmful effects of high cholesterol.lysine. It seems to reduce the incidence of osteoporosis and infectious conditions such as cold sores and genital herpes. It is the most frequently limiting amino acid in cereals and nuts, but it is abundant in dairy products, fish, and legumes.

How are proteins complemented?

The body needs a balanced supply of all the essential amino acids in the right proportion.: that makes it possible to form your own proteins with the best possible quality.

When you digest protein, it breaks down into its simplest units, amino acids, and is absorbed that way. It is like a puzzle that needs to be disassembled before it can be put back together. in the disposition of each human body.

Foods like the egg, which is the germ of animal life, contain all the amino acids in proportions suitable for us, while plant-based proteins, present in legumes, cereals and nuts especially, often they can present some deficient amino acid.

In that case it is called limiting amino acid because, given its scarcity, the other amino acids are assimilated only in a similar proportion to that of the content of that amino acid, as if they lacked a partner to participate in the dance of digestion.

The protein utilization value is called UNP (Net Utilization of Proteins). or NPU, and gives us a biological value that is high for animal protein and somewhat lower for vegetables.

The limiting amino acid tends to be different in different proteins. This means that when two different foods are combined, the amino acids in a protein can…