Table of amino acids: functions, types and characteristics

Proteins (and amino acids) are one of the most popular macronutrients today, largely because foods rich in these molecules are part of many diets designed to lose weight (high-calorie diets).

But leaving aside its benefits in weight loss and the improvement of body aesthetics, proteins are one of the bases of every vital process, since they are absolutely necessary for our body and its functions are various: they allow cells to defend themselves from external agents, control and regulate functions within our body, repair damage...

• Related article: "The 20 types of proteins and their functions in the body”

Important amino acids for humans

The units with which proteins are built are amino acids (AA), and although there are hundreds of amino acids that play an important role in nature, there are only 20 that are part of proteins (protein or canonical amino acids).

However, there are also other AAs, known as non-protein, that play a determining role for humans and have their own function, for example GABA.

• You can learn more about this neurotransmitter in our article: "GABA (neurotransmitter): what it is and what role does it play in the brain"

What are non-essential amino acids

Canonical amino acids are the raw material of proteins, but these can be classified in two ways: essential and non-essential. The main difference between these types of amino acids is that some of them are synthesized by the human body and others are not, so it is necessary to get them through the diet.

The former are the non-essential amino acids, while the latter are the essential amino acids. Nonessential amino acids are just as important as essential ones. as they participate in the construction of strong muscles, as well as in the maintenance of a healthy and productive brain.

Table of amino acids

In the following lines you can find all 20 amino acids (essential and non-essential) that are part of proteins, and we explain what their functions and characteristics are.

Types of essential amino acids

The protein amino acids that the body does not synthesize and, therefore, must be ingested through the diet are the following.

1. Phenylalanine

These amino acids are associated with the feeling of well-being, as they are regulators of endorphins. Among its most important functions are the reduction of excess appetite and the reduction of pain.

Phenylalanine is also involved in the synthesis of the catecholamines adrenaline, dopamine, and noradrenaline, which promotes alertness, improves memory and learning and increases the vitality. Supplements containing this amino acid can be used to improve the Parkinson's symptoms, vitiligo, chronic pain or for the comprehensive treatment of depression.

2. Isoleucine

The deficiency of this amino acid seems to be involved in some mental and physical disorders: depression, behavioral disturbances, decreased muscle mass, etc. This AA is essential for the formation of hemoglobin and muscle tissue, and stabilizes and regulates blood sugar and energy levels. In addition, it helps in the healing of wounds, skin and bones.

3. Leucine

It is one of the 3 branched chain amino acids (BCAAs) together with isoleucine and valine, which are involved in protein synthesis. It is a powerful insulin stimulator, necessary for wound healing and bone healing. Modulates the release of enkephalins, which are natural pain relievers.

4. Lysine

It inhibits the development of viruses within the body and, as a result, is used in the treatment of Herpesas well as viruses associated with chronic fatigue syndrome. Lysine participates in the synthesis of L-carnitine together with vitamin C.

It also helps form collagen, the connective tissue present in bones, ligaments, tendons, and joints. It favors calcium and, therefore, is essential for children, as it is essential for bone formation. It also participates in the production of hormones and lowers serum triglyceride levels.

5. Threonine

Threonine is necessary for the formation of collagen and helps in the production of antibodies. It is also necessary for the normal functioning of the gastrointestinal tract and can be converted to glycine. a neurotransmitter of the central nervous system.

6. Tryptophan

One of the amino acids best known by psychologists, since it is involved in the synthesis of serotonin and melanin. Therefore, it actively participates in improving mood and helps to improve the quality of sleep.

• You can learn more about this amino acid in our article: "Tryptophan: characteristics and functions of this amino acid”

7. Valine

This amino acid competes with tyrosine and tryptophan by crossing the blood-brain barrier. The higher the valine level, the lower the levels of the other two AAs in the brain. Valine is actively absorbed and used directly by the muscle as an energy source, therefore it is not processed by the liver before entering the bloodstream.

Valine deficiency causes the other amino acids (and proteins) to be absorbed in less quantity by the gastrointestinal tract.

8. Arginine

Arginine is essential for normal activity of the immune system and for wound healing. It also participates in the release of growth hormone and increases the release of insulin and glucagon. It is a precursor of GABA, decreases the size of tumors and is necessary for spermatogenesis.

9. Histidine

Useful in the treatment of anemia due to its relationship with hemoglobin. It is a precursor to histamine and has therefore been used to treat allergies. It helps maintain the proper pH of the blood and has also been used to treat rheumatoid arthritis.

10. Methionine

Actively participates in the breakdown of fats and reduces cholesterol in the blood. Helps prevent hair, skin and nail disorders. It is an antioxidant and participates in the synthesis of RNA and DNA.

Nonessential amino acids

The essential amino acids, that is, those synthesized by the human body, are as follows.

11. Aspartic acid

Aspartic acid increases endurance and physical performance and is good for chronic fatigue. It is one of the two main excitatory amino acids, the other is glutamic acid). Helps protect the liver, participates in DNA and RNA metabolism, and improves the immune system.

12. Glutamic acid

Another of the excitatory amino acids, together with the previous one, so they share many of the functions. Improves physical performance and reduces fatigue. It is essential for the synthesis of DNA and RNA and helps protect the body and improves the immune system.

13. To the girl

Alanine is important for muscle growth and is a great source of energy for muscle. It is involved in the metabolism of sugar, increases the immune system through the production of antibodies and is essential for connective tissue.

14. Asparagine

Asparagine is the binding of aspartic acid with ATP (adenosine triphosphate). It is involved in the short-term memory process, helps remove ammonia from the body, reduces fatigue, and participates in DNA synthesis.

15. Cysteine

Cysteine ​​is an antioxidant and protects against radiation, pollution, ultraviolet light and other phenomena that cause the production of free radicals. It acts as a natural "detox" and is essential for the growth, maintenance and repair of the skin and hair. It is a precursor of the amino acid taurine and chondroitin sulfate. The latter is the main component of cartilage.

16. Wisteria

It is part of the structure of hemoglobin, and is one of the two main inhibitory neurotransmitters of the nervous system (the other is GABA). It is also part of the cytochromes, which are enzymes involved in the production of energy. Participates in the production of glucagon, which helps glycogen metabolism.

17. Glutamine

Glutamine is a precursor of two of the most important neurotransmitters in the CNS: glutamate and GABA. It allows maintaining normal and constant blood sugar levels and is involved in muscle strength and endurance. Essential for gastrointestinal function.

18. Proline

An essential component of cartilage, and therefore it is key to the health of joints, tendons and ligaments. Helps keep the heart strong. The main precursor of proline is glutamate. One of its most prominent functions is that it maintains healthy skin and joints.

19. Serine

Participates in the improvement of the immune system helping in the production of antibodies and immunoglobulins and he participates in the development of myelin sheath. Serine is necessary for the growth and maintenance of muscle.

• Related article: "Myelin: definition, functions and characteristics”

20. Tyrosine

Tyrosine is an amino acid precursor to the hormone thyroxine, which is involved in metabolic processes. It is also a precursor of growth hormone and the neurotransmitters dopamine, norepinephrine, epinephrine (adrenaline) and serotonin, thereby improving mood, sleep, clarity of thought, concentration, and the memory.