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प्रश्न
Give an account of post transcriptional modifications of a eukaryotic mRNA.
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उत्तर
The primary transcripts (hn-RNA) contain both the exons and the introns and are non-functional. Hence, it is subjected to a process called splicing where the introns are removed and exons are joined in a defined order. Intron is the portion of gene which is transcribed but not translated. In prokaryotes, hnRNA is absent so splicing in not required. hnRNA undergoes additional processing called as capping and tailing. In capping an unusual nucleotide (methyl guanosine triphosphate) is added to the 5′-end of hnRNA. In tailing, adenylate residues (200 - 300) are added at 3′-end in a template-independent manner. It is the fully processed hnRNA, now called mRNA, that is transported out of the nucleus for translation.
Process of Transcription in Eukaryotes
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संबंधित प्रश्न
Explain the process of transcription in Eukaryotes.
The amino acid attaches to the tRNA at its ______.
To initiate translation, the mRNA first binds to ______.
In eukaryotes, the process of processing of primary transcript involves ______.
On the ribosome, mRNA binds ______ and two sites in the ______ for subsequent amino acids to bind to be close enough to each other for the formation of a peptide bond.
A special feature of viruses is that they:
Ribozyme is a/an:
The most abundant type of RNA in the cell is ______.
Which of the following pair lack the unit membrane?
Sigma factor is a component of ______.
The exon part of mRNA has code for ______
Refer the given diagram. What does it represent?
Identify the correct statement.
What are the functions of methylated guanasine cap?
Observe the segment of mRNA given below.
(a) Explain and illustrate the steps involved to make fully processed hnRNA?
(b) Gene encoding RNA Polymerase I and III have been affected by mutation in a cell. Explain its impact on the synthesis of a polypeptide, stating the reasons.
Which nitrogenous base in RNA pairs with adenine during bacterial transcription?
During bacterial transcription elongation, what happens to the two DNA strands as RNA polymerase moves forward?
At which step of bacterial transcription does the sigma (σ) factor dissociate from the RNA polymerase?
Which DNA sequence element serves as the primary recognition site for the sigma factor in bacterial promoters?
Between rho-independent and rho-dependent termination, which mechanism is also known as intrinsic termination?
