Dna (deoxyribonucleic acid) meaning (what it is, concept and definition)

What is DNA (deoxyribonucleic acid):

DNA is the base macromolecule of inheritance. It is a nucleic acid that contains the information of the hereditary characteristics of each living being and the sequences for the creation of amino acids that will generate the vital proteins for the functioning of organisms.

DNA or DNA is an acronym for deoxyribonucleic acid and its main function is the storage of all the information necessary for the expression of certain characteristics, in segments called genes or packed in chromosomes.

In addition, DNA transcribes amino acid sequence information into RNA or ribonucleic acid, so that these instructions can be shielded from the nucleus to ribosomes, which will translate the information to create the proteins (amino acid chains).

In reference to what was said previously, it can be seen that DNA is coding and RNA is not coding but they work together for the transmission of genetic information.

DNA began to be studied in the year 1868 by Friedrich Miescher, who together with RNA called nucleic acids. The DNA description was first published in 1953 by Jamen Watson and Francis Crick, both of whom were awarded the 1962 Nobel Prize for Medicine.

DNA characteristics

The main characteristic of human DNA is its double helix structure, also called helical.

Where is the DNA located?

In prokaryotic cells (with no defined cell nucleus), DNA is found in the cytosol, along with the other elements that float in it. Thus. Its replication is immediate, that is, it does not need to resort to other processes to transmit genetic information at the time of cell division.

In eukaryotic cells (with a defined cell nucleus), DNA is located in the cell nucleus. There are 2 ways that DNA transmits genetic information inside:

Before cell division: it replicates and is packed with other molecules and proteins to form a larger molecule called a chromosome. In this way, during mitosis, the 2 daughter cells will carry a copy of the original DNA.

For protein translation or synthesis: the information of the sequences of 3 nitrogenous bases (codon) that will determine the functions of the proteins of the DNA of each organism need messenger ribonucleic acid (mRNA) to travel safely out of the nucleus, towards the ribosomes.

What are the functions of DNA?

DNA is characterized because it must fulfill 2 fundamental functions:

1. Replication: Must be able to replicate. In this sense, a DNA chain contains 2 strands of information that can be replicated in 2 other double chains. Expression: must be able to use the information to express hereditary characteristics or to encode proteins for the proper functioning of the organism.

DNA structure

DNA is a macromolecule with a double helix structure. The 2 strands that make up the DNA go in reverse directions joined by their nitrogenous bases (Adenine, Guanine, Cytosine and Thymine). It is for this reason that the structure of DNA is often referred to as an inverted ladder.

What are the parts of DNA?

DNA is made up of deoxyribonucleotides, nucleotide chains where each unit, in turn, is made up of 3 parts:

1. a 5-carbon sugar molecule (deoxyribose for DNA and ribose for RNA), a phosphate group, and 4 nitrogenous bases (Adenine, Guanine, Cytosine, and Thymine in DNA; Adenine, Guanine, Cytosine, and Uracil for RNA).

Replication of DNA

DNA replication occurs before the cell divides and consists of obtaining identical copies of the fundamental cellular information for its transfer from one generation to another, thus constituting the basis of genetic inheritance.

The coiled DNA (chromosome) is unraveled by the enzyme topoisonerase so that the enzyme helicase then works, breaking the hydrogen bonds of the nitrogenous bases (Adenine, Guanine, Cytosine and Thymine) to separate the 2 strands.

Each strand has a directionality and each end is called 5 'and 3' (five prime and three prime), being that it is only possible to add nucleotides at the 3 'end, that is, the elongation direction will always be from 5' to 3 '.

Taking this into account, the nucleotides that will be paired with the information of a strand will be added by the DNA polymerase in the 5 'to 3' direction, where the Adenine hydrogenated bases always bind with the Thymine, the Thymine always with the Adenine, Guanine always with Cytosine and Cytosine always with Guanine.

DNA transcription

The nucleotide sequence established on a strand of DNA is transcribed into messenger RNA (mRNA). The transcription of DNA into the corresponding mRNA is similar to the DNA replication process, in the sense of the association of the nitrogenous bases.

In this way, the Adenine hydrogenated bases bind with the Uracil, the Thymine always continue to bind to the Adenines, the Guanine always with the Cytosine and the Cytosines always with the Guanine.

After transcription is complete, the corresponding mRNA will transport the information to the ribosomes to begin the translation or synthesis of proteins.

DNA and RNA

DNA and RNA are nucleic acids and together they are responsible for maintaining, replicating, storing and transporting the genetic information that defines each living being. Thanks to this information, the unique characteristics of

DNA stands for deoxyribonucleic acid, it has a deoxyribose sugar and its nitrogenous base is composed of: adenine, cytosine, guanine and thymine. It is characterized by having 2 strands wound together to form a double helix.

In turn, RNA, that is, ribonucleic acid, contains ribose sugar, its nitrogenous base is made up of: adenine, cytosine, guanine and uracil. It consists of a single strand.

However, they are both nucleic acids composed of sugars, a phosphate group and a nitrogenous base.

DNA, chromosome and genes

DNA is the helical chain that contains the genetic and protein synthesis information of each organism. It is packaged into chromosomes at the time of meiosis or cell division, the preparatory phase so that the daughter cells each have an exact copy of the original DNA.

Instead, a gene is a segment of the DNA chain that defines or expresses a certain inherited characteristic.

DNA types

Recombinant DNA

Recombinant or recombinant DNA is a genetic recombination technology, that is, they identify genes (DNA segments that express certain characteristics of an organism), combine them and create new sequences. That is why this technology is also called in vitro DNA.

Mitochondrial DNA

Mitochondrial DNA is a fragment of nucleic acid in mitochondria. Mitochondrial genetic material is inherited exclusively from the maternal side. Mitochondrial DNA was discovered by Margit MK Nass and Sylvan Nass using the electron microscope and a marker sensitive to mitochondrial DNA.

Mitochondria are small organelles within eukaryotic cells, in order to produce energy for the cell to do its job. However, each mitochondria has its own genome and its cellular DNA molecule.