Ch. 14 RNA Molecules and RNA Processing Flashcards
(32 cards)
What are the 3 regions of mature mRNA?
5’ untranslated region
protein-coding region
3’ untranslated region
True or False: in prokaryotes, the mRNA that is made is ready for translation
True
What sequences in prokaryotes is located in the 5’ UTR and helps the ribosome bind during translation
shine dalgarno sequence
In bacteria, transcription occurs ___ as translation
at the same time and place
In eukaryotes, transcription occurs ___ as translation
before and different place
In eukaryotes, the mRNA transcript is called ___ right after transcription
pre-mRNA
Which of the following are methods of pre-mRNA processing?
addition of 5’ cap
3’ cleavage and addition of poly(A) tail
RNA splicing
Why do we have a 5’ cap?
helps the ribosome bind
increases stability
Why do we have the poly(A) tail?
increase stability
helps export the mRNA from the nucleus
helps with binding to ribosome
Why do we have RNA splicing?
remove introns
True or False: prokaryotes have introns
False
In the 5’ cap, which nucleotide is added?
modified G
How is the 5’ cap connected to the first nucleotide?
5’ to 5’
What happens first?
3’ cleavage
Which three sequences in RNA splicing are highly conserved?
5’ consensus sequence
3’ consensus sequences
a branch point
Which enzyme does the splicing?
spliceosome
Splicing steps order
pre-mRNA is cut at 5’ splice site
lariat is formed
pre-mRNA is cut at 3’ splice site
lariat is degraded and exons are spliced together
What refers to the two ways that a single pre-mRNa can be processed to form many types of mature mRNA?
alternative processing
What are two methods of alternative processing?
multiple 3’ cleavage sites
alternative splicing
3’ cleavage sites remove ___
everything after that point
alternative splicing removes___
exons in the middle
If an exon is split in half, what occurred?
3’ cleavage sites
What shape is tRNA?
cloverleaf
Which type of RNA makes up the ribosome?
rRNA