RNA processing

Question 1

5’ cap

Answer 1

addition of an extra guanine at the 5’ end
-this additions takes place rapidly after the initiation of transcription

Question 2

Poly(A) tail

Answer 2

addition of 50-250 adenine to the 3’ end without a template
-increases stability of the mRNA molecule, protecting RNA from nucleases

Question 3

Exons

Answer 3

coding regions of RNA

Question 4

Introns

Answer 4

noncoding regions of RNA
-removed during splicing

Question 5

spliceosome

Answer 5

protein and RNA structure in which splicing takes place
- made up of snRNA and snRNP

Question 6

tRNA processing

Answer 6

converts a pre-tRNA transcript into a functional tRNA molecule

Question 7

important tRNA processing sites

Answer 7

-anti codon sequence
-3’ amino acid attachment site

Question 8

steps for tRNA processing

Answer 8

1. cleavage/trimming at 5’ and 3’ ends
2. removal of intron
3. CCA sequence added to 3’ end for amino acid attachment
4. modification of bases

Question 9

microRNA (miRNA)

Answer 9

endogenous RNA, transcribed from gDNA
-help regulate gene expression

Question 10

small interfering RNA (siRNA)

Answer 10

exogenous RNA, like a virus, endogenous machinery uses as host defense
-similar to microRNA but comes from out of the body to control gene expression
(CRISPR)