Adenine: Definition, Chemical Properties, Structure, Function, Synthesis, Metabolism and Pathophysiology

Together with thymine, they were discovered in 1885 by Albrecht Kossel, a German biochemist.

It is a member of the base pair AT (adenine-thymine) present in DNA.

Adenine, together with the four organic nucleobases, make up the nucleotides that make up the nucleic acid chains, such as ribonucleic acid RNA and deoxyribonucleic acid DNA.

It is also part of several other biologically relevant molecules, for example, adenosine triphosphate (ATP), the nicotinamide adenine dinucleotide (NADH), and the flavin adenine dinucleotide (FADH2).

The molecule of adenosine triphosphate is the primary source of energy at the cellular level; adenine is also present in natural substances such as tea, beets, and other substances in the human body as urine.

Chemical properties

  • Nombre IUPAC: 6-aminopurina.
  • Fórmula molecular: C5H5N5.
  • Molecular time: 135.106 g / mol.
  • Melting point: > 300 ° C or 573 ° K.

Bases nitrogenates

The nitrogenous bases in biology are mainly five and are divided into two groups:

Those that are derived from the structure of purine are called purine bases, and those that are derived from pyrimidine are called pyrimidine bases, which are cyclic compounds.

 

Together with two or more nitrogen atoms, these bases form the fundamental part of the nucleotides, nucleosides, and nucleic acids and are cyclic organic compounds.

The puric bases, pyrimidine bases are:

  1. Adenina (A).
  2. Timina (T).
  3. Citosina (C).
  4. Guanine (G).
  5. Uracilo (U).

In the DNA, the first four bases are present and in the RNA, instead of thymine, is the uracil.

Complementarity

In search of the most significant simplification, each nitrogenous base is represented by a letter:

Adenina “A”, timina “T”, guanina “G”, citosina “C” y uracilo”U”.

The nitrogenous bases tend to complement each other and, in turn, make pairs.

Thus, adenine and thymine are complementary (AT), guanine, and cytosine (GC).

The complementarity of the base in the RNA is established between adenine and uracil (AU), which replaces the thymine that is not present in this compound.

The complementarity of the bases is the key to the structure of DNA. It has significant scope since it allows the processes of replication of deoxyribonucleic acid or DNA and the translation of ribonucleic acid or RNA into proteins.

Structure

In its chemical structure, the adenine is composed of a ring of aromatic carbon with six members next to a call with five members.

The carbon atoms 1, 3, 7, and 9 are present in the ring’s structure and are replaced by four nitrogen atoms.

The C6 atom is linked to an amino group (6-aminopurine).

The structure is a double helix in the form of a spiral staircase; each base is coupled with a specific command, forming the steps of the stairs.

When it comes to the double-stranded molecules present in the DNA helix, adenine forms two hydrogen bonds with the thymine molecule that is opposite through one of the hydrogen atoms attached to the amino group of C6.

But in RNA molecules, adenine pairs through two hydrogen bonds with the uracil molecule.

When the adenine is part of an N-glycosidic bond with the case of the C1 atom of ribose, through its N9 bit of the five-membered ring, the final product is a nucleoside: adenosine.

But if adenine is coupled to deoxyribose, the resulting nucleoside is a deoxyadenosine.

The adenosine molecule can also be phosphorylated at C5, and depending on the amount of phosphate, the resulting nucleotide is called:

  1. Adenosine monophosphate or AMP.
  2. Adenosine diphosphate or ADP.
  3. Adenosine triphosphate or ATP.

Function

In a DNA molecule, the bases composed of adenine and located in the chain constitute chemical bonds, with the bases formed of thymine that are located in the opposite chain.

The sequence in four bases of DNA encodes the genetic instructions that the cell possesses.

The form of adenine called adenosine triphosphate (ATP) behaves like an energy storage molecule and is used to perform many cellular chemical reactions in the body.

Synthesis and metabolism

The human organism is capable of synthesizing adenine by itself.

Because this metabolic pathway consumes a lot of energy, the body can reuse the purine-derived adenine from the nucleotide rescue path, cut it off from the nucleic acid molecules destined for degradation, and bind ribose whenever necessary.

The degradation of adenine results in hypoxanthine and uric acid.

Pathophysiology

The biosynthesis of purine and pyrimidine are events that are regulated with great accuracy.

The mechanisms ensure their production in adequate quantities and, at times, adjusted to physiological demands that are variable, such as, for example, in cell division.

The diseases of humans that include abnormalities in the metabolism of purine are:

  1. The drop.
  2. The Lesch-Nyhan syndrome.
  3. Deficiency of adenosine deaminase.
  4. The lack of nucleoside purine phosphorylase.

Elevated levels of metabolized adenine produce a non-physiological amount of uric acid or hyperuricemia that can crystallize in the kidneys, the efferent urinary tract, especially the joint capsules, which makes urinary stones or gout.