Belkov human body produces a lot, they are diverse in composition and work performed, but blood plasma protein plays a vital role in many processes, without which human life would become impossible.
Blood plasma proteins are very diverse. There are about one hundred types of proteins in humans. With UAC ( general analysis blood), the amount of protein in the blood plasma signals how the synthesis of amino acids is carried out in the body.
Metabolic processes carried out with the help of proteins indicate how well the body is able to cope with various ailments: from the penetration of infection to the rupture of capillaries in the walls of blood vessels.
Most plasma proteins are produced in the liver, but some are synthesized in tissues bone marrow and lymph nodes.
The functions of blood plasma proteins are enormous and depend on the specification of a particular type of protein. Their main functions are to maintain the required colloid osmotic blood pressure in the vessels, but proteins also have many other tasks.
Here are some of them:
- the amount of proteins is directly proportional to the ability of blood to clot;
- proteins provide acid-base balance internal environment the body, being a buffer blood system;
- plasma protein albumin and some other proteins transport to internal organs cholesterol, bilirubin and medications;
- the complement system and globulins ensure the balance of the body's humoral immunity;
- protect against damage to blood cells and vessel walls;
- The activity of proteins in creating the necessary supply of amino acids in the bloodstream provides the body with normal functioning during periods of nutrient deficiency;
- certain types of proteins are capable of dilating blood vessels, while reducing arterial pressure, others, on the contrary, constrict blood vessels if necessary, and thus blood pressure increases.
To determine the amount of proteins in blood plasma, do biochemical analysis blood sample.
Deviations from the norm in the amount of proteins of one type or another, disturbances in their structure are signs of various ailments.
However, when making a diagnosis, it would be wrong to focus only on the protein composition of the blood - after all, with all their diversity, blood plasma proteins make up only about 7-8% of the number of all protein cells in the body.
Therefore, doctors operate with the totality of all data from tests and examinations of the patient when diagnosing and determining the therapeutic course of treatment.
Depending on the quality of protein molecules, such as water solubility or insolubility, proteins can be called simple or complex.
Simple protein molecules include a type of soluble blood plasma protein called albumin. Roughly speaking, all other proteins belong to complex protein structures.
The name of this or that insoluble blood plasma protein can be found out by dividing the proteins into fractions.
This is done by different methods, but the most common method of separating blood plasma proteins into fractions is electrophoresis.
The electrophoretic method of distributing protein molecules into fractions is based on the fact that different proteins move differently on the carrier under the influence of current.
As the latter, a cellulose acetate film is taken, onto which blood serum is applied.
The film is placed on a special frame so that its edges are in containers with electrolyte.
After passing electric current Small proteins with the highest charge (albumin) move faster than others.
Globulins, as the largest and electrically neutral molecules, practically do not move along the film.
Protein fractions
There are methods using which it is possible to isolate more than 20 protein fractions, but in conventional laboratory conditions The electrophoretic fractionation method is most often used.
Using electrophoresis, five protein fractions are isolated:
- albumins;
- α 1 - globulins;
- α 2 -globulins;
- β-globulins;
- γ-globulins.
Albumin is the most abundant in blood plasma. They are produced by the liver in large quantities.
The lifespan of albumin is very short - about 11 - 15 g of these protein molecules are synthesized and decomposed per day.
Their function is to maintain the required pressure in blood osmosis, since albumins are soluble proteins and have the smallest mass among all other protein molecules.
Albumin affects the degree of blood clotting, acid-base balance, carry out the delivery of long-chain acids, bilirubin, hormones, and drugs to internal organs.
Albumin neutralizes Ca₂+ and Mg₂+ ions. In addition to all this, albumins create reserve reserves of necessary amino acids in the blood plasma.
Globulins of fraction α 1 are produced by bone marrow tissues. These are insoluble protein structures with low mass.
However, α 1 - globulins are hydrophilic, which allows them to transport fats.
Such α 1 - globulins, such as prothrombin, are involved in the process of blood clotting and have an inhibitory effect on certain enzymes.
The majority of α2-globulins are synthesized by the liver, but approximately 25% are produced by bone marrow tissue.
These are bipolymer structures whose main function is regulatory activity.
Macroglobulin is responsible for acute phase inflammatory phenomena in the body, haptoglobin in combination with hemoglobin prevents anemia, and with the help of ceruloplasmin, copper balance is maintained in tissues.
β-Globulins are produced half in the liver and half in the bone marrow.
These include:
- fibrinogen, which is involved in the formation of fibrin threads at the site of a ruptured vessel or capillary;
- low density lipoprotein protein structures;
- transcobalamin, responsible for the synthesis of vitamin B₁₂;
- transferrin, which delivers iron to tissues;
- protein structures that make up the complement system;
- β-lipoproteins that transport phospholipids and cholesterol.
The production of γ-globulins mainly occurs with the help of B lymphocytes, but 1/10 of them are synthesized by paired Cooper cells.
This fraction of plasma proteins includes immunoglobulins, which protect the body from the penetration of foreign cells by producing antibodies to them.
What is dysproteinemia?
Normal concentrations of protein fractions in blood plasma in healthy person are presented in the table below.
Biochemical studies of protein fractions using electrophoresis make it possible to determine deviations in the concentrations of protein structures from the normal state.
This kind of pathology is called dysproteinemia, which comes in two types:
- hyperproteinemia;
- hypoproteinemia.
Hyperproteinemia, or an increase in the amount of proteins in the blood plasma, can be relative or absolute.
Relative hyperproteinemia is considered a condition of the body that, with proper treatment of the causes of the pathology, will return to normal on its own.
It happens with injuries, cuts, burns, dehydration from vomiting. Absolute hyperproteinemia occurs when the concentration of γ-globulins in the blood increases.
It is often called γ-globulinemia. The cause of this condition is most often inflammatory processes in the chronic or acute phase.
However, a significant concentration of α 1 - globulin can also cause infectious lesions in the body, abdominal operations, injuries, liver diseases.
Hypoproteinemia most often occurs when there is a lack of albumin in the blood plasma.
This condition occurs with the following pathologies:
- due to a lack of albumin production by the liver due to decreased functional abilities this body;
- with significant protein utilization in extensive burns;
- for malignant tumors;
- as a result of a severe septic condition;
- with nephrotic syndrome;
- due to prolonged fasting;
- with heavy blood loss.
However, most often dysproteinemia is accompanied by a decrease in the amount of proteins in one fraction and an increase in the other.
Electrophoresis makes it possible to distinguish the acute stage of inflammatory processes from the chronic one.
At acute stage the concentration of albumin in the blood plasma is low, but the number of globulins α 1 - and α 2 - fractions increases.
At chronic stage inflammatory process the concentration of β-globulins in the blood plasma increases.
Liver diseases are characterized by a decrease in albumin and an increase in the amount of β-globulins.
However, there are conditions of the human body in which dysproteinemia is considered a physiological phenomenon.
For example, in newborn children the amount of proteins of all fractions is reduced, and only by the age of two or three years their proteinogram indicators gradually return to normal.
In pregnant women with gestosis, the concentration of proteins in the blood plasma may also be reduced.
Despite the fact that a biochemical blood test with determination of protein concentrations by fraction can provide doctors with a lot of necessary and useful information, no one will focus only on the proteinogram when making a diagnosis, because some diseases can give the same variations in changes in the concentration of proteins in the blood plasma.
For example, with nephrotic syndrome, the concentration of albumin, α 1 - and γ-globulins decreases and the number of α 2 - and β-globulins increases.
Dysproteinemia of the same kind can be observed in other diseases, accompanied by changes in the amount of proteins of different fractions.
Amins came into our lives completely unexpectedly. Until recently, these were toxic substances, a collision with which could lead to death. And now, a century and a half later, we are actively using synthetic fibers, fabrics, building materials, dyes based on amines. No, they did not become safer, people were simply able to “tame” them and subjugate them, deriving certain benefits for themselves. We'll talk about which one further.
Definition
For quality and quantification aniline in solutions or compounds, a reaction is used, at the end of which a white precipitate in the form of 2,4,6-tribromoaniline falls to the bottom of the test tube.
Amines in nature
Amines are found everywhere in nature in the form of vitamins, hormones, and intermediate metabolic products; they are found both in the body of animals and in plants. In addition, the decay of living organisms also produces medium amines, which in the liquid state distribute bad smell herring brine. The “cadaveric poison” widely described in the literature appeared precisely thanks to the specific amber of amines.
For a long time, the substances we were considering were confused with ammonia because of their similar smell. But in the mid-nineteenth century, the French chemist Wurtz was able to synthesize methylamine and ethylamine and prove that when burned they release hydrocarbons. This was the fundamental difference between the mentioned compounds and ammonia.
Production of amines in industrial conditions
Since the nitrogen atom in amines is in the lowest oxidation state, the reduction of nitrogen-containing compounds is the simplest and most in an accessible way receiving them. It is this type that is widely used in industrial practice because of its low cost.
The first method is the reduction of nitro compounds. The reaction during which aniline is formed is named by the scientist Zinin and was carried out for the first time in the mid-nineteenth century. The second method is to reduce amides using lithium aluminum hydride. Primary amines can also be recovered from nitriles. The third option is alkylation reactions, that is, the introduction of alkyl groups into ammonia molecules.
Application of amines
By themselves, in the form of pure substances, amines are rarely used. One of the rare examples is polyethylene polyamine (PEPA), which in domestic conditions facilitates the hardening of epoxy resin. Basically a primary, tertiary or secondary amine is an intermediate product in the production of various organic matter. The most popular is aniline. It is the basis of a large palette of aniline dyes. The color you get in the end depends directly on the selected raw material. Pure aniline produces a blue color, but a mixture of aniline, ortho- and para-toluidine will be red.
Aliphatic amines are needed to produce polyamides, such as nylon and others. They are used in mechanical engineering, as well as in the production of ropes, fabrics and films. In addition, aliphatic diisocyanates are used in the manufacture of polyurethanes. Due to their exceptional properties (lightness, strength, elasticity and the ability to attach to any surface), they are in demand in construction (foam, glue) and in the footwear industry (anti-slip soles).
Medicine is another area where amines are used. Chemistry helps synthesize antibiotics from the sulfonamide group from them, which are successfully used as second-line drugs, that is, backup. In case bacteria develop resistance to essential drugs.
Harmful effects on the human body
It is known that amines are very toxic substances. Any interaction with them can cause harm to health: inhalation of vapors, contact with open skin, or ingestion of compounds into the body. Death occurs from a lack of oxygen, since amines (in particular, aniline) bind to hemoglobin in the blood and prevent it from capturing oxygen molecules. Alarming symptoms are shortness of breath, blue discoloration of the nasolabial triangle and fingertips, tachypnea (rapid breathing), tachycardia, loss of consciousness.
If these substances get on bare areas of the body, you must quickly remove them with cotton wool previously soaked in alcohol. This must be done as carefully as possible so as not to increase the area of contamination. If symptoms of poisoning appear, you should definitely consult a doctor.
Aliphatic amines are poison for the nervous and cardiovascular systems. They can cause depression of liver function, its dystrophy and even oncological diseases Bladder.
Aromatic amines are derivatives of aromatic hydrocarbons in which one or more hydrogen atoms of the benzene ring are replaced by amino groups (N.H. 2 ).
Aromatic amines can also be considered as derivatives of ammonia, in the molecule of which one or more hydrogen atoms are replaced by aromatic radicals.
As in the aliphatic (fatty) series, aromatic amines can be primary, secondary or tertiary.
Depending on which radicals (only aromatic or aromatic and aliphatic) are associated with the nitrogen atom, a distinction is made between purely aromatic and fatty-aromatic.
The amino group can be directly connected to the core or located in the side chain.
Aniline is the founder of the class of aromatic amines, in which the amino group is directly bonded to the benzene ring:
aniline (phenylamine, aminobenzene)
Nomenclature of aromatic amines
Aromatic amines are usually named trivial nomenclature.
For example, aniline, toluidine.
According to systematic (substitute) nomenclature the names of amines are formed from the names of radicals with the addition of the ending -amine or consoles amino
Trivial: ortho-toluidine meta-toluidine para-toluidine
Substitute: ortho-tolylamine meta-tolylamine para-tolylamine
ortho-aminotoluene meta-aminotoluene para-aminotoluene
(2-aminotoluene) (3-aminotoluene) (4-aminotoluene)
An aromatic ring can have two or more amino groups.
The names of compounds with two amino groups (diamines) are formed from the name of the divalent carbon residue and the ending –diamine or consoles diamino- and the name of the corresponding hydrocarbon:
o-phenylenediamine m-phenylenediamine p-phenylenediamine
o-diaminobenzene m-diaminobenzode p-diaminobenzene
(1,2-diaminobenzene) (1,3-diaminobenzene) (1,4-diaminobenzene)
Depending on the number of radicals associated with the nitrogen atom, secondary and tertiary aromatic amines are also distinguished.
The names of secondary and tertiary amines are most often formed according to the principles rational nomenclature, listing the radicals present in the compound and adding the ending -amine:
diphenylamine (secondary amine)
triphenylamine (tertiary amine)
If in an amine molecule both aromatic and aliphatic radicals are simultaneously bound to a nitrogen atom, then such amines are called fatty-aromatic.
In the case of fatty aromatic amines, the name is based on the word "aniline" and, to show that the radical is located at the nitrogen atom and not in the benzene ring, the name of the radical is preceded by the letter N:
N-methylaniline N,N-dimethylaniline
Rational: methylphenylamine dimethylphenylamine
Substitute: N-methylaminobenzene N,N-dimethylaminobenzene
Amines with an amino group in the side chain:
benzylamine
α-aminotoluene
Aromatic amines with an amino group in the side chain have the properties of aliphatic amines.
Amines- organic derivatives of ammonia, in the molecule of which one, two or all three hydrogen atoms are replaced by a carbon residue.
Usually isolated three types of amines:
Amines in which the amino group is bonded directly to an aromatic ring are called aromatic amines.
The simplest representative of these compounds is aminobenzene, or aniline:
Basic distinctive feature electronic structure of amines is the presence of a nitrogen atom included in functional group, lone pair. This causes amines to exhibit the properties of bases.
There are ions that are the product of the formal replacement of all hydrogen atoms in the ammonium ion by a hydrocarbon radical:
These ions are found in salts similar to ammonium salts. They are called quaternary ammonium salts.
Isomerism and nomenclature
1. Amines are characterized by structural isomerism:
A) carbon skeleton isomerism:
b) functional group position isomerism:
2. Primary, secondary and tertiary amines are isomeric to each other ( interclass isomerism):
As can be seen from the examples given, in order to name an amine, the substituents associated with the nitrogen atom are listed (in order of precedence) and the suffix is added -amine.
Physical properties of amines
The simplest amines(methylamine, dimethylamine, trimethylamine) - gaseous substances. The rest lower amines- liquids that dissolve well in water. They have a characteristic odor reminiscent of ammonia.
Primary and secondary amines are capable of forming hydrogen bonds. This leads to a noticeable increase in their boiling points compared to compounds having the same molecular weight, but not capable of forming hydrogen bonds.
Aniline is an oily liquid, sparingly soluble in water, boiling at a temperature of 184 °C.
Aniline
The chemical properties of amines are determined in mainly due to the presence of a lone pair of electrons on the nitrogen atom.
Amines as bases. The nitrogen atom of the amino group, like the nitrogen atom in the ammonia molecule, due to lone pair of electrons can form covalent bond through the donor-acceptor mechanism, acting as a donor. In this regard, amines, like ammonia, are capable of attaching a hydrogen cation, i.e., acting as a base:
1. Reaction of amions with water leads to the formation of hydroxide ions:
A solution of amine in water has an alkaline reaction.
2. Reaction with acids. Ammonia reacts with acids to form ammonium salts. Amines are also capable of reacting with acids:
Basic properties of aliphatic amines are more pronounced than those of ammonia. This is due to the presence of one or more donor alkyl substituents, the positive inductive effect of which increases the electron density on the nitrogen atom. An increase in electron density turns nitrogen into a stronger electron pair donor, which improves its basic properties:
Combustion of amions. Amines burn in air to form carbon dioxide, water and nitrogen:
Chemical properties of amines - summary
Application of amines
Amines are widely used to obtain medications, polymer materials . Aniline is the most important compound of this class, which is used for the production of aniline dyes, medicines ( sulfa drugs), polymer materials (aniline formaldehyde resins).
Reference material for taking the test:
Mendeleev table
Solubility table
Amines- This organic compounds, in which a hydrogen atom (maybe more than one) is replaced by a hydrocarbon radical. All amines are divided into:
- primary amines;
- secondary amines;
- tertiary amines.
There are also analogs of ammonium salts - quaternary salts like [ R 4 N] + Cl - .
Depending on the type of radical amines can be:
- aliphatic amines;
- aromatic (mixed) amines.
Aliphatic saturated amines.
General formula CnH 2 n +3 N.
Structure of amines.
The nitrogen atom is in sp 3 hybridization. The 4th non-hybrid orbital contains a lone pair of electrons, which determines the basic properties of amines:
Electron-donor substituents increase the electron density on the nitrogen atom and enhance the basic properties of amines, for this reason secondary amines are stronger bases than primary ones, because 2 radicals on a nitrogen atom create a greater electron density than 1.
In tertiary atoms, the spatial factor plays an important role: because 3 radicals obscure the lone pair of nitrogen, which is difficult for other reagents to “approach”; the basicity of such amines is less than primary or secondary.
Isomerism of amines.
Amines are characterized by isomerism of the carbon skeleton and isomerism of the position of the amino group:
What are amines called?
The name usually lists the hydrocarbon radicals (in alphabetical order) and adds the ending -amine:
Physical properties of amines.
The first 3 amines are gases, the middle members of the aliphatic series are liquids, and the higher ones are solids. The boiling point of amines is higher than that of the corresponding hydrocarbons, because in the liquid phase, hydrogen bonds are formed in the molecule.
Amines are highly soluble in water; as the hydrocarbon radical grows, solubility decreases.
Preparation of amines.
1. Alkylation of ammonia (main method), which occurs when an alkyl halide is heated with ammonia:
If the alkyl halide is in excess, the primary amine can undergo an alkylation reaction, becoming a secondary or tertiary amine:
2. Reduction of nitro compounds:
Ammonium sulfide is used ( Zinin's reaction), zinc or iron in acidic environment, aluminum in an alkaline medium or hydrogen in the gas phase.
3. Reduction of nitriles. Use LiAlH4:
4. Enzymatic decarboxylation of amino acids:
Chemical properties of amines.
All amines- strong bases, and aliphatic ones are stronger than ammonia.
Aqueous solutions are alkaline in nature.
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