The deoxyribonucleic acid , better known as DNA , is a type of molecule full structure is located within each of the cells of the human body and containing in its inside all the information and instructions necessary to create and subsequently maintain life .
What is deoxyribonucleic acid?
The deoxyribonucleic acid is a type of molecule consisting of two chains which can be found all the genetic information that have beings living and some types of virus .
- Definition of deoxyribonucleic acid
- Components (edit)
- Physical properties of deoxyribonucleic acid
- Chemical properties
- Where is it located
- Deoxyribonucleic acid applications
- How it differs from RNA
Definition of deoxyribonucleic acid
Deoxyribonucleic acid is a basic macromolecule for humans and for heredity, since it is where all the information related to the hereditary characteristics of living beings is located. It is also the most important component of chromosomes and is responsible for indicating the formation of proteins that turn out to be necessary to maintain the proper functioning of cells, tissues and organisms.
There are many characteristics of deoxyribonucleic acid. The most important ones are mentioned below:
- Its molecules are linked in such a way that they form a chain .
- It is found within cells and is dispersed in the cytoplasm or in the cell nucleus .
- It contains all the genetic information that is inherited and that will later be inherited.
- Its shape is complex and elongated .
- Each DNA is unique and different .
- It is made up of fundamental units called nucleotides .
- In eukaryotic cells, DNA is located in the cell nucleus .
The history of DNA begins in 1869 thanks to the Swiss biologist Friedrich Miescher who studied the chemical composition of white blood cells . In his experiment, he found a substance that was rich in phosphates and that was also resistant to proteases, in addition, this molecule was not a protein and it was not a lipid. He named the molecule nuclein , a name that he later obtained from the generic name of nucleic acid .
During the 1920s, Phoebus Levene , carried out a series of studies based on nucleic acids and it was when he managed to determine the presence of two different molecules, DNA and RNA and determined that the basic unit of DNA was formed by a nitrogenous base of phosphate and sugar and gave it the name nucleotide .
Thanks to Griffith in 1928 , the findings made by Avery in 1944 and several experiments by the scientist Hershey-Chase in 1952 , it was possible to determine that DNA was responsible for transmitting the hereditary traits of the living beings. In 1929 , Maurice Wilkins, Rosalind Franklin, Francis Crick and James Watson discovered the molecular structure of DNA, a double helix , which earned them the Novel Prize in Medicine in 1962.
DNA has a structure composed of long strips in which nucleotides are located . Each of these nucleotides is composed of a sugar molecule , a phosphate group that fulfills the function of serving as a link between nucleotides and a nitrogen base which has four important components: adenine (A), thymine (T ), guanine (G) and cytosine (C). It is precisely the order of these nitrogen bases that indicates and determines the DNA instructions.
These nucleotides are joined together to form two long , spiral- shaped chains and a double helix structure is formed with them . Its molecules are so long that, in order to reach inside the cell, the DNA coils forming what we know as chromosomes .
The components that are part of deoxyribonucleic acid are the following:
- Adenine (A)
- Thymine (T)
- Guanine (G)
- Cytosine (C).
Physical properties of deoxyribonucleic acid
Among the main physical properties of deoxyribonucleic acid we can find the following:
- The DNA strand measures between 22 to 26 Angstroms or their equivalent of 2.2 to 2.6 nanometers wide.
- Its nucleotide is 3.3 Å or 0.33 nm long.
- In the case of DNA polymers , these can be large .
- Its type of structure is double helix.
- When DNA replication occurs, it unwinds so that it can be copied .
- It can also be unrolled so that its instructions can be used to make proteins and to perform some other biological processes .
- When cell division occurs , DNA maintains its compact chromosomal shape to allow its transfer to new cells .
Its main chemical properties are mentioned below:
- Each DNA molecule is a chain of chemically linked nucleotides , each of which is made up of a sugar , a phosphate, and one of the four types of bases .
- Since DNA strands are made up of nucleotide subunits , they are considered polymers .
- The DNA genome in a human being contains about 3 billion bases and about 000 genes on 23 pairs of chromosomes.
- DNA can be divided and degraded by enzymes called nucleases.
- After a DNA molecule has been assembled, it can be chemically modified , sometimes deliberately by special enzymes called DNA methyltransferases and sometimes accidentally by oxidation , ionizing radiation, or the action of chemical carcinogens.
Three different types of DNA can be found:
- DNA-A : It is a right double helix similar to the form of DNA-B. DNA assumes an A form that protects DNA under extreme conditions such as desiccation. Protein binding also removes the solvent from the DNA and the DNA assumes an A form.
- B-DNA : It is the most common type of DNA and is a right helix . Most DNA has a B-type conformation when under normal physiological conditions.
- Z-DNA: Z- DNA is a left helix in which the double helix winds to the left in a zigzag fashion . It is found at the beginning of a gene and is believed to play some role in gene regulation.
The main function of deoxyribonucleic acid is to store all the genetic information that an individual has, it is responsible for containing all the genetic data that will later be inherited from one person to another and from generation to generation. Another of its functions is to transcribe the information found in the amino acid sequences in ribonucleic acid so that these instructions can be protected on their way from the nucleus to the ribosomes.
The formula for deoxyribonucleic acid is C5H10O4 .
Where is it located
In eukaryotic cells, deoxyribonucleic acid is located within the nucleus of cells while in prokaryotic cells , it is located dispersed within the cytoplasm . In viruses , DNA can be found in mitochondria and chloroplasts .
Deoxyribonucleic acid applications
Deoxyribonucleic acid has several fields of application, including the following:
- Forensic Sciences : In this field, it is used to determine the profile of DNA , a technique by means of which unique attributes of an individual can be determined. It is used for paternity or maternity tests , in forensic medicine and in the identification of victims after some type of disaster.
- DNA profiling in medicine : it is used to locate genes that are related to some specific diseases such as breast cancer.
- It is also applied in biotechnology , pharmacogenomics and the study of the ancestors of humans and other types of organisms. This use is of great importance mainly for research in the field of molecular biology , livestock , agriculture and biomedicine .
- Cancer study : these studies are based on the analysis of specific genetic data to study the disease with the aim of improving diagnoses and treatments .
How it differs from RNA
There are several differences between DNA and RNA. The function of deoxyribonucleic acid is to be able to store and transfer genetic information, while the function of RNA is to be able to interpret the genetic codes it has in DNA in order to produce protein synthesis. Furthermore, DNA has a double stranded while RNA has a single stranded . Finally, the nitrogenous bases of RNA are adenine, thymine, cytosine and guanine while those of RNA are adenine, uracil, cytosine and guanine.
Deoxyribonucleic acid is extremely important because it is responsible for maintaining all the genetic information necessary to be able to give life to a living being similar to the one from which it originates, in other words, it is responsible for transmitting the genetic code of a individual to another. It is the one in charge of coordinating and controlling all the activities and functions of the cells and also carries all the genes that have the function of coding for proteins .