The creation of the building block of life ( the process of proteine synthesis )
We are all aware that DNA holds an important role in the functioning of all species, in fact, it holds the information that is responsible for how an organism is built and how it reacts with its environment. This is why we sometimes compared it to the blueprint of life.
But unfortunately, not a lot of people know that Protein can be considered as the second most import molecule. As a matter of fact, if DNA is the blueprint of life then protein is the building block of life.
Actually, the DNA is used to create protein in a process called the central dogma of molecular biology or the central dogma of protein synthesis. This process explains how the information in the DNA is transported to the ribosome ( the protein-making machine ).
First step: get out of the nucleus.
DNA can be found in the chromosomes and in eukaryotic cells (cell with a nucleus) chromosome are situated and always stay in the nucleus but unfortunately, the protein-making machine ( the ribosome ) is situated in the cytoplasm outside of the nucleus so our organisms need a way to get the genetic informatic contained in the DNA out of the nucleus and to the ribosome. There are two processes involved in it which are transcription and translation.
Transcription, the first step consists of complying the genetic information from the DNA to a ribonucleic acid or RNA for short. RNA are small enough to be able to squeeze through the pore of the nucleus and go to the ribosome. During the process of transcription, a strand of messenger RNA or mRNA ( a subtype of the RNA molecule ) is made complementary to a gene.
Transcription takes place in three-step which are initiation, elongation, and termination.
- Initiation is the beginning of transcription, this step consists of binding enzymes to the mRNA.
- The next step elongation consists of putting nucleotides to the mRNA strand.
- Termination is the end of transcription and consist of the mRNA detaching from the DNA after this step the mRNA is complete.
Finishing to prepared the mRNA.
Unfortunately, the new mRNA molecule created by the transcription step is not fully ready for the translation step. At this stage, the mRNA is called pre-mRNA and need to go through some more step before it is fully ready like adding altered nucleotide on the 5′ end ( 5' cap ), splitting, editing and the adding of a long chain of adenine nucleotides at the end ( 3' polyadenylation tail ). Those steps modify the mRNA in various ways allowing the single gene to be used to make more than just one protein.
Those steps are important for a multitude of reason here is three import one.
- The 5' cap added to serve as a protection to the mRNA when it is in the cytoplasm and helps in the attachment of mRNA with the tRNA molecule in the translation step.
- Splicing eliminate introns ( intron are regions that do not code for protein ) from the mRNA, what is left is exclusively region named exons those are the region that code for proteins.
- Polyadenylation adds a tail-like structure at the end of the mRNA. This tail acte as a stop signal it signals the end of the mRNA and, it is also involve into putting the mRNA out of the nucleus and also help protects the mRNA from enzymes that might break it.
Translation or how amino acid transform into protein.
The last step is translation and it consists of taking the encoding that is in the mRNA and translates it into a chain of amino acid that will then folded itself into a protein.
The translation begins when the nucleus leaves the nucleus and move to a ribosome. The ribosome read the sequence of codons on mRNA and a molecule called tRNA brings amino acid to the ribosome in the correct sequence. Just as mRNA synthesis can be divided into 3 phases translation can also be divided into 3 phases that are initiation, elongation, and termination.
- initiation consists of a small subunit that binds to a site upstream of the start of the mRNA it then proceeds to scan the mRNA in the 5' to the 3' direction until it sees the start codon .
- In the elongation phase, the ribosome shifts one codon at a time and interact with other RNA molecules to make a chain of amino acids called polypeptide chains.
- termination occurs when a stop codon (UAA, UAG, or UGA) is encountered by the ribosome it then released the growing polypeptide with the help of different releasing factors after
Finally, the remaining polypeptide may go under other processes for example it may fold itself into a 3d shape or it may bind with other polypeptides. When those prices terminated the protein is fully complete.
TL;DR
The DNA is used to create protein in a process called the central dogma of molecular biology or the central dogma of protein synthesis. This process explains how the information in the DNA is transported to the ribosome ( the protein-making machine ).
There are two processes involved in it which are transcription and translation.
Transcription, the first step consists of complying the genetic information from the DNA to a ribonucleic acid or RNA for short. RNA are small enough to be able to squeeze through the pore of the nucleus and go to the ribosome. During the process of transcription, a strand of messenger RNA or mRNA ( a subtype of the RNA molecule ) is made complementary to a gene.
The last step is translation and it consists of taking the encoding that is in the mRNA and translates it into a chain of amino acid that will then folded itself into a protein.
