An RNA molecule is created from a DNA sequence during transcription by the enzyme RNA polymerase. Let us know whether or not transcription occur in nucleus.
Transcription occurs in the nucleus of eukaryotes whereas prokaryotes have cytoplasmic transcription, It constructs an RNA (mRNA) molecule using a template made of DNA. Transcription results in the production of a corresponding mRNA strand to the DNA strand.
Making a copy of the DNA sequence of a gene in RNA is the aim of transcription. The RNA copy, that codes for proteins contains the instructions needed to assemble a polypeptide.
When does transcription occur in the nucleus?
Transcription is the mechanism through which the cell controls which proteins are to be made and at what pace. Let us know when transcription occurs in nucleus.
Transcription occurs in the nucleus of eukaryotic cells during the G1 and S phases of the cell cycle. To initiate transcription by catalysing the production of mRNA, an enzyme called RNA polymerase attaches to the template DNA strand.
A dozen or so subunits make up the big enzyme polymerases, which are frequently complexed with other components while they are active on DNA. These elements frequently provide gene’s transcription target with a signal.
How does transcription occur in the nucleus?
Nucleolus is the substructure of the nucleus that is most visible. It is where transcription occurs. Let us see how transcription occurs in the nucleus.
RNA pol is linked to a promoter sequence near the start of a gene to start transcription either directly or via helper proteins inside the nucleus. A complementary strand is then formed by using the DNA strand as a template. Finally, termination occurs that brings transcription to a conclusion.
Transcription takes place in a cell’s nucleus since the genes are bound there, but the mRNA transcript needs to be delivered to the cytoplasm.
Why does transcription occur in the nucleus?
Nucleus carries the genes and structures that hold the genetic information. Let us understand the reason behind the occurrence of transcription in nucleus.
Transcription takes place inside the nucleus due to the presence of some enzymes in it. DNA is required for protein synthesis. Hence, allowing DNA to leave the nucleus can be risky. As a result, transcription takes place, and the required DNA portion is copied and synthesised into mRNA within the nucleus.
The RNA is expelled from the nucleus after making contact with the ribosome. The tRNA anticodon is subsequently assisted by the ribosome in binding to the mRNA codons, leading to the production of protein by ribosomes.
How do transcription factors enter the nucleus?
Transcription factors are proteins that bind to nearby DNA to help turn specific genes “on” or “off”. Let us understand how these transcription factors enter nucleus.
Transcriptional factors are activated and are moved from cytoplasm (where most transcription factors are found) into the nucleus where they bind with the relevant DNA frame after receiving a signal from cell membrane signal transduction.
Transcription factors control transcription by attracting proteins to the promoter region that change the composition and locations of nucleosomes.
What happens during the transcription in the nucleus?
Transcription is the conversion of genetic information from DNA to RNA. Let us see the process that happens during the transcription in nucleus in details .
The transcription of DNA takes place over the course of three primary processes.
- Initiation
- Elongation
- Termination
Initiation:
Initiation describes the beginning of transcription. Interaction between the gene’s promoter and the RNA polymerase enzyme causes it to happen. In order for the enzyme to “read” specific base in a particular DNA strands, this tells the DNA to unwind.
Elongation:
The mRNA strand receives nucleotides during elongation. Using complementary base pairs, RNA polymerase assembles the mRNA molecule by reading the unravelled DNA strand. During this process, uracil (U) from the RNA forms a link with adenine (A) from the DNA.
Termination:
Termination occurs when RNA polymerase passes a stop (termination) sequence in the gene, putting an end to transcription. The finished mRNA strand separates from the DNA.
Why does transcription not occur in the cytoplasm?
In prokaryotes transcription occurs in cytoplasm while in eukaryotes transcription takes place in the nucleus. The reason for this is mentioned below.
The process of transcription in eukaryotes dose not occur in the cytoplasm because DNA and other enzymes that are required for the occurrence of the process is present inside the nucleus. After this process, the mRNA formed is transferred into the cytoplasm for translation.
Conclusion:
Transcription is a key early process in gene expression. Through the procedures of transcription and translation, genetic information is transferred sequentially from DNA to proteins. The resulting RNA is known as mRNA, and transcription only copies one strand of DNA, the template strand. Transcribing a DNA sequence into RNA accomplishes its main objective. A protein’s RNA transcript carries the information needed to encode it.
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Hi…I am Sadiqua Noor, done Postgraduation in Biotechnology, my area of interest is molecular biology and genetics, apart from these I have a keen interest in scientific article writing in simpler words so that the people from non-science backgrounds can also understand the beauty and gifts of science. I have 5 years of experience as a tutor.
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