RNA Processing and editing

Question 1

What is the product of transcription?

Answer 1

• precusor molecule
• pre-mRNA

Question 2

WHat is pre-mRNA modified into? Why does it do this?

Answer 2

• forms mature mRNA
• before it can bind to a ribosome
• and code for the synthesis opf the required protein

Question 3

What is a cap and tail?

Answer 3

• cap
  
  • a modified nucleotide
• tail
  
  • long chain of adenine nucleotides

Question 4

What is done with the cap and tail?

Answer 4

• a cap is added to the 5’ end oand a tail (a long chain of adenine nucleotides) is added to the 3’ end.

Question 5

What is the function of the addition of adding a cap and tail?

Answer 5

• stabalise mRNA and delay degradation in the cytoplasm
• the cap also aids binding of mRNA to ribosomes

Question 6

What is splicing?

Answer 6

• splicing occurs where the RNA is cut at specific points
  
  • the introns (non-coding DNA) are removed
  • and the exons (coding DNA) are joined together

Question 7

How is RNA edited?

Answer 7

• nucleotide sequence of some mRNA molecules changed through:
  
  • base addition
  • base deletion
  • base substitution

Question 8

WHhat is the effect of RNA editing?

Answer 8

• same effect as point mutations
• result in the synthesis of different proteins which may have different functions
  *

Question 9

What is the function of RNA editing?

Answer 9

this increases the range of proteins that can be produced from a single mRNA molecule or gene