mRNA Processing and Modifications

The video tutorial explains the processing of mRNA before it can be used by ribosomes to build proteins. Key steps include the addition of a methylated cap and a polyadenylated tail. The process begins with transcription, where RNA polymerase adds a methylated cap to the 5' end. After transcription, cleavage factors bind to specific sequences, and the 3' end is cleaved and degraded. Poly A polymerase then adds adenine residues to form a polyadenylated tail. The processed mRNA is then ready for splicing and translation.

Why is mRNA processing necessary before it can be used by ribosomes?

• To remove the mRNA from the nucleus

• To increase the mRNA's length

• To protect the mRNA from degradation

• To change the mRNA's sequence

What is the first modification made to mRNA during processing?

• Addition of a methylated cap

• Cleavage of the 3' end

• Splicing of introns

• Addition of a polyadenylated tail

What role do cleavage factors play in mRNA processing?

• They add a methylated cap to the mRNA

• They bind specific nucleotide sequences for cleavage

• They synthesize the polyadenylated tail

• They splice the mRNA

How is the 3' end of mRNA prepared for cleavage?

• By splicing out introns

• By binding of stabilizing factors

• By adding a methylated cap

• By adding adenine residues

What enzyme is responsible for synthesizing the polyadenylated tail?

• Cleavage factors

• Spliceosome

• Poly(A) polymerase

• RNA polymerase

What happens to the 3' end of mRNA after cleavage?

• It is capped with a methyl group

• It is exported from the nucleus

• It is spliced

• It is degraded quickly

What signals poly(A) polymerase to stop adding adenine residues?

• The mRNA is exported from the nucleus

• The tail reaches its full length

• The mRNA is fully spliced

• The 5' cap is added

What is the final step in mRNA processing before translation?

• Export from the nucleus

• Addition of a methylated cap

• Cleavage of the 3' end

• Splicing of the mRNA