Histidine: formula, chemical reactions
Each of us at least once in my life thought aboutits food. Here, for example, what daily rate of various substances necessary for the body comes to us with food? What amino acids do we need and for what? Today, of course, we will not talk about proper nutrition as a whole, since there is not enough one and even a dozen articles for this. We will tell only about one substance, which, undoubtedly, is very important for the organism. This is the amino acid histidine. Its chemical name sounds complicated - L-2-amino-3- (1H-imidazol-4-yl) propanoic acid. But first things first.
What is an amino acid?
Before discussing the properties of histidine and itsrole in the body, we will understand the concept of "amino acid". Those who were fond of sports, heard about these substances. An amino acid is an organic compound having two basic functional groups that make it special: an amino group-NH2and the so-called carboxyl group -COOH.
The first is responsible for the basic properties of thisan unusual class of compounds. Thanks to nitrogen and its electron pair, the amino acid can form positively charged ions. In this case, the amino group is transformed into such an ion: -NH3+.
The second functional group is responsible for the acid properties. It is capable of giving up a proton, turning into an anion -COO-. This phenomenon makes it possible to form salts from the carboxyl group.
Thus, the amino acid has two parts,each of which is capable of forming salts. One of them provides these compounds with the properties of acids, and the other with bases. In general, the amino acid can be represented as follows: NH2-CH (R) -COOH. The letter R should be understood here as a "radical", that is, an organic particle consisting of functional groups and a carbon skeleton and capable of forming a bond (or bonds) with the base of the amino acid molecule.
As a rule, even those who are not familiar withpharmacology and did not get involved in sports, at least once heard, even from advertising, that we need amino acids and are very useful. Let's figure out what functions they perform in the body and why you need to get them in the necessary rate from food.
Functions of amino acids in the body
As you know, we all consist of proteins, fats andcarbohydrates. And we consume them for food to maintain our viability. But in the subject of this article we are only interested in proteins. These are huge molecules that carry out completely different and very important functions in our body: the transport of substances, the creation of new cells, the strengthening of connections between neurons of the brain.We talked about proteins for a reason. The fact is that all such substances consist of amino acids, including histidine. The formula of even the simplest protein includes at least a dozen amino acids linked to a polypeptide chain. Each of them has its own structure and form, which allows it to perform the function for which it was created by nature.
The formula of any amino acid includes, as we already havehave found out, at least two functional groups and a carbon skeleton connecting them. That is why the difference between all amino acids (which, by the way, is found several million already) is the length of the carbon bridge between the two groups and in the structure of the radical attached to it.
The topic of our article is one of the amino acids -histidine. The formula of this irreplaceable acid is not simple. In the main carbon chain between the two functional groups, we see only one carbon atom. In fact, all the indispensable proteinogenic (able to create proteins) amino acids also have only one carbon atom in this chain. In addition, histidine has a complex radical structure comprising a cycle. Above you can see what a histidine is. A formula whose structural feature is a heterocycle (inclusion of some other atoms other than carbon) is in fact not the most complex substance.
So, once we have analyzed the basic concepts, we turn to reactions that can be carried out with histidine.
The reactions in which this amino acid enters,very few. In addition to reactions with acids and bases, it enters a biuret reaction, forming colored products. In addition, histidine, the formula of which includes imidazole residues, can interact with sulfanilic acid in the Pauli reaction.
Perhaps, we have disassembled all the main details. We hope that the article was useful for you and gave you new knowledge.