What is DNA? DNA Replication, DNA Structure, and Differences

What is DNA?

DNA or deoxyribonucleic acid is a polymer essential for life, which is found inside all cells of living beings and most viruses. It is a complex, long protein, inside which all the genetic information of a person is stored, that is, the instructions for the synthesis of all the proteins that make up the body: it can be said that it contains molecular instructions for survival. is.

The minimal units of this genetic information are called genes and contain a specific sequence of nucleotides that make up DNA and allow its hereditary transmission, something important for the development of life. These structures also contain information about when and how the basic components of cells should be synthesized.

DNA is contained in cells, either in their cytoplasm (in the case of prokaryotic organisms: bacteria and archaea) and within the cell nucleus (in the case of eukaryotes: plants, animals, fungi). Its decoding and use as a template require the intervention of RNA or ribonucleic acid, which reads the structure and uses it as a template, in a process known as transcription/translation.

It must be said that each person’s DNA is unique and distinct, a process is a product of a combination of the genetic code of its parent that occurs at random. This is, of course, in organisms of sexual reproduction, in which each parent contributes half of their genome to create a new person. In the case of asexual reproduction of single-celled organisms, the DNA molecule reproduces itself in a process called replication.

The genetic material of DNA is extremely valuable for life, and despite this, exposure to mutations may cause damage to it: radiation, certain chemical elements, or even certain drugs (such as chemotherapy In this case), which would give rise to transcription errors at the time of cellular synthesis. It can also lead to illness and death of the individual, or hereditary transmission of defective structures, giving rise to offspring with congenital defects.

What is DNA? DNA Replication, DNA Structure, and Differences

DNA Structure

The DNA molecule is a long string of units called nucleotides, which in turn consist of a sugar molecule (in this case deoxyribose: C5H10O4), a nitrogenous base (which may be adenine, guanine, cytosine, or thymine. ), And a phosphate group that acts as a link between nucleotides. Therefore, each nucleotide is separated from the others in nitrogen bases, and that they all together span a series called DNA sequences and which can be transferred using the initials of each base, for example, ACTAGTCAGT …

DNA also has a double helix shape, wound in three different patterns (called A, B, and Z), according to its sequence, number of bases, and specific function. This structure occurs due to the union of two nucleotide strips by hydrogen bonding.

What is DNA? DNA Replication, DNA Structure, and Differences

What is DNA replication?

Replication is the process by which a DNA molecule generates two identical molecules by itself and is important in cellular reproduction because all cells in the body must have the same genome (as in asexual reproductive organisms, which are mutually identical. Are practical clones of).

The process involves the separation of two strands of DNA, each of which will serve as a template to synthesize a new partner. If all goes well, eventually, the original DNA will have two identical molecules, both in a double helix. Therefore, replication is the key to inheritance.

Three types of DNA replication are assumed:

Semiconservative. As described before, the strands are separated and a new one is synthesized from each of the old ones.

Conservative. It would take place if the two old strands, after serving as a template, were reunited with their old partner and in the end, there was an entirely new DNA molecule, next to the old one that would be reconstituted.

Dispersive. It would occur if the resulting helices were made up of old and new DNA fragments.

Differences between DNA and RNA

DNA and RNA are similar nucleotide chains, but they differ, as their name implies, in the type of sugar present in their structure: deoxyribose and ribose, respectively.

Also, RNA is almost four times larger than DNA, and it is made up of one single helix, instead of two. This distinction is also functional since DNA contains the genetic template and RNA is in charge of executing or transporting it.

Mendel’s role in DNA discovery

Nevertheless! The role of other scientists in the discovery of DNA has been immense. But if Mendel wasn’t there, today we wouldn’t even think about DNA in Hindi. At the beginning of the 20th century, a lot of research on hereditary science was done thanks to Mendel.

This was the reason that Walter Fleming discovered chromatin in the mid-19th century. friend! If he doesn’t know, let me tell him that chromatin is called a network made up of chromosomes.

What is DNA? DNA Replication, DNA Structure, and Differences

What is DNA? DNA Replication, DNA Structure, and Differences

Definebiology.com

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