The process of making an exact copy of DNA before the cell divides is called DNA Replication. Before the division, all cells must go through this process to make sure that the genetic information they contain is available for the production of proteins when needed.
Basics
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When talking about genetics, the term ‘DNA replication‘ usually comes out. While people are very interested in the subject, most of them do not even know what DNA is, let alone what is DNA replication. They know that DNA is very important and that it has a major part in the development and functioning of all living organisms, but they do not know what is DNA exactly.
So before talking about DNA replication, we should start by settling once and for all what is DNA. Well, DNA stands for deoxyribonucleic acid, which is a nucleic acid containing all our genetic information. The DNA is made out of structures called genes, but there are also other DNA sequences, which serve various purposes. It is also very important to learn some basics about DNA Structure. However, since we have covered it in another article, we are not going to repeat it here. Instead, we are going to present a birds-eye-view of the DNA replication process.
Basically, DNA is an essential macromolecule for all the known forms of life. Now that you know what DNA is, we should move on to what is DNA replication. DNA replication is a very complex process, which occurs in all living organisms, as all known forms of life have DNA.
This biological process copies the DNA of the previously mentioned living organisms, so this is how the genetic information is being transmitted from parents to children. DNA replication begins with one double-stranded DNA molecule, and it produces two identical copies of that molecule. In plain English, the genetic information contained by both of the strands combines and merges into a simple unit. You can see. Thus, that DNA replication is the reason why children inherit features from both parents because their DNA contains genes from both of them.
However, DNA replication occurs on lower scales too, because this process is vital for cells to multiply, as well. This process occurs even in the prokaryote cells. DNA replication begins in the genome, at specific locations called ‘origins’.
Due to the latest developments in technology, DNA replication can also be performed artificially, ‘in Vitro, but only in special laboratories.
How does DNA Replication work?
Eukaryote cells and prokaryote cells
The field for the DNA replication process is different for eukaryote cells and prokaryote cells. For earlier ones, it mostly happens within the nucleus, however, for the latter ones, the location is cytoplasm. No matter what be the location, the activities are very much alike and the reason is the same, i.e. the cell (parent) has to make an exact copy of DNA to transfer its all characteristics and information to the new cell (daughter).
DNA replication happens all the time in our body but significantly important is that life begins and depends on it as an embryo uses DNA and RNA (similar structure as DNA with a small difference) instructions to grow and become an organism. This new organism has all the characteristics of its parents, for this reason, a human has a human baby and a plant produces seeds.
Double helix splits up
Before cell division, the double helix splits up, exposing the bases to RNA in the cytoplasm. RNA starts attaching with bases. This process is bi-directional as it happens on both ends of the replication fork (a notch where DNA replication starts) simultaneously in different directions. In one strand it pairs up in fragments called Okazaki fragments.
When the replication is done, fragments start joining. Finally, they recoil into a double helix. As two strands of DNA are copied simultaneously, so the original DNA makes two copies of itself by each strand. The replicated DNA in new cells is considered semi-conservative because it has 50% of the original genetic matter taken over from its parent.
Changes in DNA replication cause minor or fatal results. Once the DNA is mutated, it would copy itself as truly as the original one so the mutated organism would transfer its defects to its offspring. Consequently, some heredity diseases transfer from generation to generation, and some diseases like cancer spreads in the infected body only.
Nevertheless, now that you know what is DNA, and also what is DNA replication, I am sure that you better understand the complex process of how life is created.
