Amino acids - what are they used for? Amino acids in products. Reactions and properties of amino acids

In nature, there are two groups of substances: organic and inorganic. The latter include compounds such as hydrocarbons, alkynes, alkenes, alcohols, lipids, nucleic acids and other acids, proteins, carbohydrates, amino acids. For what these substances are needed, we will tell in this article. The composition of all organic compounds necessarily includes atoms of the carbon and hydrogen. They can also contain oxigen, sulfurur, nitrogen and other elements. Science, studying proteins, acids, oxides, amino acids, - chemistry. She explores the properties and characteristics of each group of substances.

Amino acids - what are these substances for?

They are very important for the organism of any living creature on the planet, as they are a component of the most significant substances - proteins. In total, there are twenty-one amino acids, of which these compounds are formed. Each consists of the atoms of hydrogen, nitrogen, carbon and oxygen. The chemical structure of these substances has an amino group NH2, from which the name derives.

How do proteins form of amino acids?

These organic substances are formed in four stages, their structure consists of primary, secondary, tertiary and quaternary structures. From each of them depends certain properties of the protein. Primary determines the number and order of amino acids located in the polypeptide chain. The secondary is an alpha helix or a beta structure. The former are formed due to the twisting of the polypeptide chain and the occurrence of hydrogen bonds within one. The second - because of the formation of bonds between groups of atoms of different polypeptide chains. The tertiary structure is an interconnected alpha helix and a beta structure. It can be of two types: fibrillar and globular. The first is a long thread. Proteins with this structure are fibrin, myosin, found in muscle tissues, and others. The second has the form of a tangle, globular proteins include, for example, insulin, hemoglobin and many others. In the organism of living beings, special organelles of the cell-the ribosome-correspond to the synthesis of proteins from amino acids. The information about the proteins that must be produced is encrypted into DNA and transferred to the ribosomes by RNA.

What are the amino acids?

The compounds of which proteins are formed, there are twenty-one in nature. Some of them the human body is able to synthesize in the course of metabolism (metabolism), while others - not. In general, there are such amino acids in nature: histidine, valine, lysine, isoleucine, leucine, threonine, methionine, phenylalanine, tryptophan, cysteine, tyrosine, arginine, alanine, glutamine, asparagine, glycine, proline, carnitine, ornithine, taurine, serine. The first nine of the above amino acids are irreplaceable. Also there are conventionally irreplaceable - those that the body can use instead of irreplaceable in extreme cases. This, for example, tyrosine and cysteine. The first can be used in place of phenylalanine, and the second - if there is no methionine. Essential amino acids in foods are a prerequisite for a healthy diet.

What kind of food do they contain?

• Valine is meat, fish.
• Histidine - buckwheat porridge, cereals, red fish, pork, poultry.
• Izoleucin - eggs, meat, fish, milk, cheese, cottage cheese.
• Leucine - the same as isoleucine.
• Methionine - cereals, peanuts, walnuts, pistachios, cereals.
• Threonine - meat, cereals, mushrooms.
• Tryptophan - turkey, rabbit, pork, horse mackerel.
• Phenylalanine - meat, beans, peas, lentils, soy, fish, cottage cheese, milk, cheese.

All other amino acids in foods consumed by humans may not be contained, since the body is able to produce them on its own, however, it is still desirable that some part of them come with food. Most of the interchangeable amino acids are contained in the same products as the irreplaceable, that is, meat, fish, milk - that food that is rich in protein.

The role of each amino acid in the human body

Each of these substances performs a certain function in the body. The most essential amino acids for vital activity are irreplaceable, so it is very important to eat foods with their content in sufficient quantities. Since the main building material for our body is protein, we can say that the most important and necessary substances are amino acids. For what we need irreplaceable, we'll tell you now. As it was already written above, this group of amino acids include histidine, valine, leucine, isoleucine, threonine, methionine, phenylalanine, tryptophan. Each of these chemical compounds plays its own specific role in the body. So, valine is necessary for full-fledged growth, so products with a high content of it must necessarily be kept in sufficient quantities in the diet of children, adolescents and athletes who need to increase the concentration of muscle mass. Histidine also plays an important role - it participates in tissue regeneration process, it is a part of hemoglobin (that's why at low blood levels it is recommended to increase the amount of buckwheat used). Leucine is needed by the body in order to synthesize proteins, and also to maintain the activity of the immune system at the proper level. Lysine - without this substance, the body simply does not absorb calcium, so you should not allow the lack of this amino acid - you need to include more fish, cheese and other dairy products in your diet. Tryptophan is needed for the production of vitamin B, as well as hormones that regulate hunger and mood. This substance is part of the drugs that help to calm and eliminate insomnia. Phenylalanine is used by the body to produce hormones such as tyrosine and adrenaline. This substance can also be a part of medical drugs that are prescribed for insomnia or depression.

Amino acids in terms of chemistry

You already know that the components of proteins and vital substances for a person are amino acids. For what these compounds are needed, we have already considered, now we turn to their chemical properties.

Chemical properties of amino acids

At each of them they are a bit individual, although they have common features. Since the composition of amino acids can be different and include different chemical elements, the properties will also vary slightly. A common feature for all substances in this group is the ability to condense to form peptides. Also, amino acids can react with nitrous acid, forming hydroxy acids, water and nitrogen. In addition, they interact with alcohols. This forms the hydrochloride salt of any ether and water. For such a reaction, the presence of hydrochloric acid as a catalyst in the gaseous aggregate state is necessary.

How to identify their presence?

To determine the presence of these substances, there are special qualitative reactions of amino acids. For example, to detect cysteine, you need to add lead acetate, and also use heating and alkaline medium. In this case lead sulphide must be formed, which precipitates in a black color. Also, the amount of amino acid in the solution can be determined by adding nitrous acid to it. Learn this by the volume of nitrogen released.