Amino acids

Amino acids, or aminocarboxylic acids, are organic compounds whose molecules form amine and carboxyl groups.

General characteristics

Amino acids are usually crystalline substances with a sweet taste, which can be obtained during the hydrolysis of proteins or as a result of certain chemical reactions. These solid water-soluble substances-crystals are characterized by a very high melting point - about 200-300 degrees Celsius. The main chemical elements of amino acids are carbon, nitrogen, hydrogen, oxygen.

Although the name of these substances contains the word “acid”, their properties are more like salts, although due to the specifics of the structure of the molecule they can have acidic and basic abilities at the same time. So - it is equally effective to act with acids and alkalis.

Most amino acids come in two forms: L-isomers and D-isomers.

The former are characterized by optical activity and are found in nature. Amino acids of this form are important for the health of the body. D-substances are found in bacteria, play the role of neurotransmitters in the organisms of some mammals.

In nature, there are 500 so-called standard, proteinogenic amino acids. 20 of them actually make up the polypeptide chain containing the genetic code. In recent years, science has been talking about the need to expand the amino acid "family", and some researchers supplement this list with 2 more substances - selenocysteine ​​and pyrrolysine.

Amino acids in the human body

them. Most cells and tissues in the human body are made up of amino acids, which play a key role in the transport and storage of nutrients.

Interestingly, in nature, only plants and some microorganisms are able to synthesize all kinds of amino acids. But people (and animals) can only get some essential amino acids from food. Based on the ability to synthesize, these useful substances are divided into 2 groups:

  • essential (the body receives only from food);
  • replaceable (produced in the human body).

Essential amino acids are: arginine, valine, histidine, isoleucine, leucine, lysine, methionine, threonine, tryptophan, phenylalanine.

Non-essential amino acids: alanine, asparagine, aspartate, glycine, glutamine, glutamate, proline, serine, tyrosine, cysteine.

And although the body is able to synthesize arginine and histidine, these amino acids are also among the essential ones, as there is often a need to supplement their reserves from food. The same can be said about tyrosine, which can move from its group of essentials to the list of essentials if the body feels a lack of phenylalanine.

Popular classifications

In the scientific world, different parameters are used to classify amino acids. There are several classifications used for these substances. As already noted, there are nonessential and nonessential amino acids. Meanwhile, this classification does not reflect the objective degree of importance of each of these substances, since all amino acids are significant for the human body.

Other most popular classifications

Taking into account radicals, amino acids are divided into:

  • non-polar (alanine, valine, isoleucine, leucine, methionine, proline, tryptophan, phenylalanine);
  • polar uncharged (asparagine, glutamine, serine, tyrosine, threonine, cysteine);
  • polar with a negative charge (aspartate, glutamate);
  • polar with a positive charge (arginine, lysine, histidine).

Considering group functionality:

  • aromatic (histidine, tyrosine, tryptophan, phenylalanine);
  • heterocyclic (histidine, proline, tryptophan);
  • aliphatic (in turn create several more subgroups);
  • imino acid (proline).

Considering biosynthetic families of amino acids:

  • pentose family;
  • pyruvate family;
  • aspartate family;
  • serine family;
  • glutamate family;
  • Shikimat family.

According to another classification, 5 types of amino acids are distinguished:

  • sulfur-containing (cysteine, methionine);
  • neutral (asparagine, serine, threonine, glutamine);
  • acidic (glutamic acid, aspartic acid) and basic (arginine, lysine);
  • aliphatic (leucine, isoleucine, glycine, valine, alanine);
  • aromatic (phenylalanine, tryptophan, tyrosine).

In addition, there are substances whose biological properties are very similar to amino acids, although in fact they are not. A striking example is taurine, which is not quite rightly called an amino acid.

Amino acids for bodybuilders

Bodybuilders also have their own classification of amino acids. In sports nutrition, 2 types of nutrients are used: free amino acids and hydrolysates. The former include glycine, glutamine, arginine, which are characterized by the maximum speed of transportation. The second group is proteins broken down to the level of amino acids. Such substances are absorbed by the body much faster than conventional proteins, which means that the muscles get their "portion" of proteins faster.

Essential amino acids are also of particular importance for bodybuilders. They are important for maintaining the shape of muscle tissue. And since the body is not able to synthesize them on its own, it is important for bodybuilders to include in the diet a large amount of meat and dairy products, soy and eggs. In addition, those who want to build muscle resort to supplements containing amino acids.

For health and beauty

In addition to playing an important role in the synthesis of enzymes and proteins, amino acids are important for the health of the nervous and muscular systems, for the production of hormones, and also maintaining the structure of all cells in the body.

And for bodybuilders, amino acids are one of the most significant substances, as they contribute to the restoration of the body. Being the basis for proteins, amino acids are indispensable substances for beautiful muscles. These useful elements help to make training more effective, and relieve pain after training. As a dietary supplement, they prevent the destruction of muscle tissue and are an ideal addition to a protein diet. Also, the functions of amino acids include burning fat and suppressing excessive appetite.

Daily requirement: to whom and how much

Daily dosages are determined separately for each amino acid, based on the needs and characteristics of the body. Meanwhile, the average values ​​fluctuate between 0.5 and 2 g per day.

Increasing the level of consumption of amino acid complexes is important for people professionally involved in sports, as well as during increased physical activity, intense mental work, during and after illness. The correct balance of amino acids is important for children during the growth period.

The daily norms of the amino acid complex for bodybuilders are from 5 to 20 g of the substance for a single dose. Meanwhile, when combining the intake of these nutrients with sports nutrition, it is important to know some rules. The effectiveness of amino acids (absorption rate) is significantly reduced if they are consumed with food or its substitutes, proteins or gainers.

At the same time, people with genetic diseases (in which the absorption of amino acids is impaired) should not exceed the recommended daily doses. Otherwise, protein foods can cause changes in the functioning of the gastrointestinal tract, allergies. In addition, diabetics, people with liver disease, or those suffering from certain enzyme deficiencies are at risk of developing an amino acid imbalance.

When consuming protein foods, one should remember that amino acids are absorbed most quickly from egg whites, fish, cottage cheese and lean meats. And for a more intensive assimilation of nutrients, nutritionists advise combining products correctly. Milk, for example, is combined with white bread or buckwheat, and proteins from cottage cheese or meat are paired with flour products.

The cause of hormonal problems

The lack of any useful substances, as a rule, affects health. Decreased immunity, anemia and lack of appetite are a signal of a serious imbalance of nutrients. Insufficient intake of amino acids causes hormonal disturbances, absent-mindedness, irritability and depression. In addition, weight loss, skin problems, dysplasia, and drowsiness are also indicative of an amino acid deficiency.


An excess of amino acids, as well as a lack of nutrients, leads to disruption of the body. True, most of the negative consequences from an excess of amino acids are possible only with hypovitaminosis A, E, C, B, as well as with selenium deficiency.

Excessive use of histidine is almost always joint disease, graying at an early age, aortic aneurysm. Excess tyrosine causes hypertension, dysfunction of the thyroid gland. Methionine in large doses is a heart attack or stroke.

Where to look for essential amino acids

Most foods (mostly protein) contain about 20 amino acids, 10 of which are essential.

Meanwhile, the list of these useful substances is much wider: in nature, there are about 5 hundred amino acids. And most of them are essential for a healthy life. Some of these elements are active components of sports nutrition, dietary supplements, medications, and are also used as additives to animal feed.

An almost complete complex of essential amino acids contains:

  • pumpkin seeds;
  • pistachios;
  • cashews;
  • peas;
  • potatoes;
  • asparagus;
  • buckwheat;
  • soy;
  • lentils.

Other useful sources of amino acids: eggs, milk, meat (beef, pork, lamb, chicken), fish (cod, pike perch), various types of cheeses.

Interactions with other substances

Water-soluble amino acids combine well with ascorbic acid, vitamins A, E and group B. In combination, they can bring many times more benefits. This nuance is important to consider when compiling a menu of foods rich in vitamins and beneficial nutrients.

Amino acid supplements

Bodybuilders actively use amino acids as nutritional supplements. These nutrients are available in several forms: tablets, capsules, powders, solutions, and even intravenous injections.

The timing and frequency of amino acid supplementation depends on the purpose. If the drug is taken as an aid for gaining muscle mass, then drinking amino acids is before and after training, as well as in the morning. And if the drug in the first place should play the role of a fat burner, you should drink it more often (how often is indicated in the instructions for use).

How to choose the right amino acids

Amino acids in the form of bioactive supplements for sports nutrition, as a rule, are not cheap. And in order not to throw money away, it is important to check the quality of the goods before buying. The first step is to pay attention to the expiration date and the quality of the packaging, the consistency and color of the substance must fully comply with the description. In addition, most amino acids dissolve in water and have a bitter taste.

Essential Amino Acids Comparison Table
Amino Acid ) Application Dosage (as a dietary supplement for athletes) Overdose;


Histidine Treats arthritis, nervous deafness, improves digestion, needed for infants and children during growth 8-10 mg per 1 kg of body weight (minimum 1 g per day) Mental disorders, anxiety, schizophrenia, susceptibility to stress;


Dairy products, meat, poultry, fish, rice, rye, wheat, apples, pomegranate, beets, carrots, celery, cucumber, dandelion, chicory, garlic, radishes, spinach, turnips
Lysine body, important for absorption and retention of calcium, promotes the formation of collagen 12 mg per 1 kg of body weight Increased cholesterol, diarrhea, gallstones;

Violation of enzyme production, weight loss, loss of appetite, deterioration in concentration.

Cheese, eggs, milk, beans, potatoes, meat, yeast, soybeans, lettuce, tofu, apples, apricots, grapes, papaya, pears, beets, carrots, celery, cucumber, dandelion greens, parsley, spinach, turnip
Phenylalanine muscle tension, important for the production of neurotransmitters serotonin and melatonin 1 mg per 1 kg of weight High blood pressure, migraines, nausea, disruption of the heart and nervous system. Not recommended for pregnant women and diabetics;

Lethargy, weakness, growth retardation, impaired liver function.

Dairy products, almonds, nuts, seeds, avocados, soybeans, sesame, beans, spinach, apples, pineapples, beets, carrots, parsley, tomatoes, brewer's yeast
Methionine Treatment of the liver, arthritis, depression, accelerates fat metabolism and improves digestion, antioxidant, prevents the accumulation of excess fat in the vessels and liver, removes toxins 12 mg per 1 kg of body weight Possible with vitamin B deficiency. Atherosclerosis;

Fatty degeneration of the liver, growth retardation, lethargy, edema, skin diseases.

Meat, fish eggs, beans, garlic, onions, lentils, sour cream, yogurt, spinach, potatoes, sesame seeds, soybeans, cereals, apples, pineapples, hazelnuts, Brussels sprouts, cauliflower, sorrel, horseradish, watercress
Leucine Prevents muscle atrophy, natural anabolic agent, promotes wound healing and is important for growth hormone production 16mg per kg body weight Increases ammonia levels;


Protein food, brown rice, beans, nuts, whole grains, wheat, soybeans, lettuce, alfalfa seeds, beans, tofu, sesame, avocado, papaya, olives, coconut
Isoleucine Heals wounds, releases growth hormone, regulates blood sugar, is important for the formation of hemoglobin, is responsible for muscle structure 10-12mg per kg body weight Causes frequent urination, use with caution in kidney or liver disease;


Eggs, fish, meat, liver, chicken, cashew almonds, lentils, soy products, watercress, chard, spinach, beans, avocados, olives, coconuts
Valine Regulates nitrogen balance, restores and promotes the growth of muscle tissue 16 mg per 1 kg weight Skin prickling, hallucinations, forbidden to people with liver or kidney disease;

Maple syrup disease.

Dairy products, meat, cereals, mushrooms, peanuts, soybeans, lettuce, sesame, peas, beans, apples, almonds, pomegranate, beets, carrots, celery, dandelion greens, lettuce, okra, parsley, parsnip, pumpkin, tomato, turnip, brewer's yeast
Threonine Important for collagen production, elastin, antibodies, maintains muscle health, stimulates growth, is used for the treatment of the psyche 8 mg per 1 kg of body weight Unknown;

Irritability, weakening of the immune system.

Meat and dairy products, eggs, lettuce, soy, spinach, sesame, sunflower seeds, beans
Tryptophan Important for the production of serotonin and melatonin, necessary during growth 3.5 mg per 1 kg of body weight Dizziness migraine, vomiting, diarrhea;

May cause tuberculosis, cancer, diabetes, dementia.

Meat and dairy products, soy products, spinach, sesame, lettuce, broccoli, asparagus, beans, oat bran, Brussels sprouts, carrots, celery, onions, chicory, dill, brewer's yeast
Arginine Responsible for muscle recovery, rapid healing of wounds and injuries, removes toxins, strengthens the immune system 0.4 mg per 1 kg of weight Diseases of the pancreas, liver;

Decreased blood pressure, weakness, indigestion.

Pork, chicken, salmon, eggs, milk, pine nuts, walnuts, pumpkin seeds, rice, buckwheat, corn, peas

Non-essential amino acids: importance for humans

Alanine - is responsible for blood sugar levels.

Asparagine - contributes to the functioning of the immune system.

Glutamine is the “fuel” for the body during especially high loads, strengthens memory, enhances attention.

Glycine is the “raw material” for making creatine and is important for maintaining vitality.

Proline - necessary for connective tissue, nourishes the body during exercise.

Serine - important for the nervous system, supplies cells with energy.

Citrulline - removes ammonia from the body.

Taurine - affects the functioning of the nervous system.

Cysteine ​​- helps cleanse the body of toxins and toxins, is responsible for hair growth.

Ornithine - essential for fat metabolism.

Amino acids, like vitamins and nutrients, are essential for maintaining health and strength. Their lack of a very sad effect on well-being. But at the same time, there is no need to “plant” the body on amino acids in the form of bioadditives (of course, if you are not a bodybuilder who dreams of a mountain of muscles). It is enough for ordinary people to adhere to proper nutrition, because almost the entire amino acid complex is contained in our daily food.

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  2. Komov V. P.: Biochemistry. – M.: Bustard, 2008