The 20 types of proteins and their functions in the body
Proteins are macronutrients formed basically by carbon, hydrogen, oxygen and nitrogen , although some also contain sulfur and phosphorus. These elements studied by biology (and the sciences related to this) explain much of the functioning of our body, both in regard to its movement and, for example, in relation to our mind. However, proteins are present in all kinds of life forms, not only in our species.
Plants synthesize inorganic nitrogen proteins, but animals, unable to perform this process, have to incorporate these substances through the diet. Proteins are formed by the union of several amino acids, linked by peptide bonds.
As these biomolecules are so important to understand what our body is like, it is useful know some of the most common types of proteins or relevant to us, and also the amino acids that forms. In this article you will find a brweve explanation of these two elements, both amino acids and proteins. Let's start with the first ones.
- Maybe you're interested: "The 4 differences between the animal and the plant cell"
What are the amino acids
As we have seen, amino acids are the basis or the raw material of proteins . Basically, they are the raw material from which our whole body is made: muscles, hairs, bones, skin and even the brain tissue that produces our thoughts, emotions and consciousness.
Although in nature it is possible to find hundreds of amino acids, only 20 are used in the formation of proteins. They are called: protein amino acids .
The 20 types of protein amino acids
The protein amino acids, also called canonical, perform physiological functions by themselves, as is the case of glycine or glutamate, which are neurotransmitters. Below you can find the 20 protein neurotransmitters:
- Recommended article: "Types of neurotransmitters: functions and classification"
1. Glutamic acid
This amino acid is considered as the gasoline of the brain and one of its main functions is to absorb excess ammonia in the body.
2. Alanina
The main task of this amino acid is that intervenes in the metabolism of the glucos to.
3. Arginine
It is present in the process of detoxification of the organism , in the urea cycle and in the synthesis of creatinine. In addition, it intervenes in the production and release of growth hormone.
4. Asparagine
It is synthesized from aspartic acid, and eliminates, along with glutamine, the excess of ammonia in the body and intervenes in the improvement of resistance to fatigue.
5. Cysteine
Involved in the process of removing heavy metals from the body and it is fundamental in the growth and health of hair.
6. Phenylalanine
Thanks to this amino acid it is possible the regulation of endorphins that are responsible for the feeling of well-being . It reduces the excess of appetite and helps to calm the pain.
7. Glycine
It helps the body in the creation of muscle mass , to the correct healing, prevents infectious diseases and participates in the correct cerebral functioning.
8. Glutamine
Glutamine is abundantly found in muscles. This amino acid increases brain function and mental activity and help solve impotence problems. In addition, it is essential to combat problems with alcohol.
9. Histidine
This amino acid is the precursor of histamine . It is abundantly found in hemoglobin and the production of both red blood cells and white blood cells in the blood is necessary. In addition, it intervenes in the growth process, in tissue repair and the formation of myelin sheaths.
10. Isoleucine
This amino acid is part of the genetic code and is necessary for our muscle tissue and the formation of hemoglobin. In addition, it helps regulate blood sugar.
11. Leucina
Like the previous amino acid, intervenes in the formation and repair of muscle tissue and collaborates in the healing of skin and bones. Further. It acts as energy in high-effort workouts and helps increase the production of growth hormone.
12. Lysine
Along with methionine, synthesizes the amino acid carnitine and it is important in the treatment of herpes.
13. Methionine
It is important to prevent some types of edema , high cholesterol and hair loss.
14. Proline
It is responsible for the synthesis of several brain neurotransmitters related to temporary depression and also collaborates in the synthesis of collagen.
15. Serine
It is an amino acid that participates in the metabolism of fats and is a precursor of the phospholipids that nourish the nervous system.
16. Taurine
Taurine strengthens the heart muscle and prevents cardiac arrhythmias. Improves vision and prevents macular degeneration.
17. Tyrosine
Tyrosine stands out for its function as a neurotransmitter and can help relieve anxiety or depression.
18. Threonine
Necessary in the process of detoxification and participates in the synthesis of collagen and elastin.
19. Tryptophan
Tryptophan is an essential amino acid, meaning that the body itself can not synthesize it and must be achieved through food. It is a precursor of the neurotransmitter serotonin, associated to the state to the state of mind. Tryptophan is considered a natural antidepressant and also promotes sleep. It is also a very healthy component and easy to find in healthy diets .
- You can know more about this neurotransmitter in this article: "Tryptophan: characteristics and functions of this amino acid"
20. Valina
Like some of the previous amino acids, It is important for the growth and repair of muscle tissues . In addition, it also intervenes in the regulation of appetite.
Essential and non-essential amino acids
Amino acids can be classified as essential and non-essential. The difference between these is that the first can not produce the body and, therefore, must be ingested through food. The 9 essential amino acids are :
- Histidine
- Isoleucine
- Leucine
- Lysine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Valina
Not all foods high in protein have the same amount of amino acids. The protein with the highest content of amino acids is the egg.
Classification of proteins
Proteins can be classified in different ways . Below you can find the different types of protein.
1. According to its origin
One of the best known classifications is according to the origin: animal proteins and plant proteins .
1.1. Animal proteins
Animal proteins are, as the name suggests, those that come from animals. For example, proteins from eggs or pork.
1.2. Vegetable proteins
Vegetable proteins are those that come from vegetables (legumes, wheat flours, nuts, etc.). For example, soy proteins or peanuts.
2. According to its function
According to its function in our organism , proteins can be classified into:
2.1. Hormonal
These proteins are secreted by the endocrine glands. Generally transported through the blood, hormones act as chemical messengers that transmit information from one cell to another.
You can know more about this type of peptide hormones in our article: "Types of hormones and their functions in the human body".
2.2. Enzymatic or catalytic
These proteins accelerate metabolic processes in cells, including liver function, digestion or converting glycogen into glucose, etc.
2.3. Structural
Structural proteins, also known as fibrous proteins, are necessary components for our body. They include collagen, keratin and elastin. Collagen is found in connective, bone and cartilage tissue just like elastin. Keratin is a structural part of hair, nails, teeth and skin.
2.4. Defensive
These proteins have an immune or antibody function, keeping the bacteria at bay. Antibodies are formed in white blood cells and attack bacteria, viruses and other dangerous microorganisms.
2.5. Storage
Storage proteins store mineral ions such as potassium or iron. Its function is important, since, for example, the storage of iron is vital to avoid the negative effects of this substance.
2.6. Transport
One of the functions of proteins is transport within our body, because they transport minerals to cells. Hemoglobin, for example, transports oxygen from tissues to the lungs.
2.7. Receptors
These receptors are usually located outside the cells to control the substances that enter inside it. For example, GABAergic neurons contain different protein receptors in their membranes.
2.8. Contractile
They are also known as motor proteins. These proteins regulate the strength and speed of the heart or muscle contractions. For example, myosin.
3. According to its conformation
The conformation is the three-dimensional orientation acquired by the characteristic groups of the protein molecule in space, by virtue of the freedom they have to turn.
3.1. Fibrous proteins
They are formed by polypeptide chains aligned in parallel. Collagen and keratin are examples. They have high resistance to cutting and are insoluble in water and salt solutions. They are the structural proteins.
3.2. Globular proteins
Polypeptide chains that roll on themselves, which causes a spherical macrostructure. They are usually soluble in water and, in general, are the transport proteins
4. According to its composition
According to its composition, the proteins can be:
4.1. Holoproteins or simple proteins
They are formed, mainly, by amino acids.
4.2. Heteroproteins or conjugated proteins
They are usually composed of a non-amino acid component, and can be:
- Glycoproteins : structure with sugars
- Lipoproteins : lipid structure
- Nucleoproteins : attached to a nucleic acid. For example, chromosomes and ribosomes.
- Metalloproteins : contain in their molecule one or more metal ions. For example: some enzymes.
- Hemoproteins or chromoproteins : They have a heme group in their structure. For example: hemoglobin.