Each of us at least once in our lives thought about our diet. For example, what is the daily norm of various substances necessary for the body that comes to us with food? What amino acids do we need and why? Today, of course, we will not talk about proper nutrition in general, since one or even a dozen articles are not enough for this. Let's talk about only one substance, which is undoubtedly very important for the body. It 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 its role in the body, let's deal with the concept of "amino acid". Those who were fond of sports have heard about these substances. An amino acid is an organic compound that has two main functional groups that make it special: the amino group -NH2 and the so-called carboxyl group -COOH.
The first is responsible for the main properties of this unusual class of compounds. Thanks to nitrogen and its pair of electrons, an amino acid can form positively charged ions. In this case, the amino group turns into this ion: -NH3+.
Second function althe group is responsible for the acidic properties. It is able to donate a proton, turning into an anion -COO-. This phenomenon makes it possible to form s alts from the side of the carboxyl group.
Thus, an amino acid has two parts, each of which is capable of forming s alts. One of them provides these compounds with the properties of acids, and the other - of bases. In general, an amino acid can be represented as follows: NH2-CH(R)-COOH. The letter R here should be understood as a "radical", that is, any organic particle consisting of functional groups and a carbon skeleton and capable of forming a bond (or bonds) with the backbone of an amino acid molecule.
As a rule, even those who are not familiar with pharmacology and were not fond of sports have heard at least once, at least from advertising, that we need amino acids and are very useful. Let's see what functions they perform in the body and why you need to get them in the required norm from food.
Functions of amino acids in the body
As you know, we are all made up of proteins, fats and carbohydrates. And we consume them as food to maintain our viability. But in the topic of this article, we are only interested in proteins. These are huge molecules that perform completely different and very important functions in our body: the transport of substances, the creation of new cells, the strengthening of connections between brain neurons.
We started talking about proteins for a reason. The fact is that all such substances consist of amino acids, which include histidine. Even the Simplest Protein Formulacontains at least a dozen amino acids connected in a polypeptide chain. Each of them has its own structure and shape, which allows it to perform the function for which it was created by nature.
Histidine
The formula of any amino acid includes, as we have already found out, at least two functional groups and a carbon skeleton connecting them. That is why the difference between all amino acids (of which, by the way, several million have already been found) lies in 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 for this essential acid is not simple. In the main carbon chain, between the two functional groups, we see only one carbon atom. In fact, all of the essential proteinogenic (capable of making proteins) amino acids also have only one carbon atom in this chain. In addition, histidine has a complex radical structure that includes a cycle. Above you can see what histidine is. The formula, whose structural feature is a heterocycle (inclusion of any other atoms than carbon), is actually far from the most complex substance.
So now that we have covered the basic concepts, let's move on to the reactions that can be carried out with histidine.
Chemical properties
The reactions that this amino acid enters into are very few. In addition to reactions with acids and bases, it enters into biuretreaction to form colored products. In addition, histidine, whose formula includes imidazole residues, can interact with sulfanilic acid in the Pauli reaction.
Conclusion
Perhaps we have covered all the main details. We hope that the article was useful for you and gave you new knowledge.
