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43 Cards in this Set
- Front
- Back
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compare RNA DNA
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ss ds
5->3 pol same OH deoxy RNA can form secondary structures like stem loops hairpin loops |
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name six types of RNA
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r ribosomal
m messenger t transfer sn small nuclear sno small nucleolar mi silencing |
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what does sn RNA do
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small nuclear is involved in mRNA processing
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what does sno RNA do
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rRNA processing
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what types of RNA are in prok? euk?
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prok have r m t
euk have sn sno mi |
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t or f. all RNA is translated into protein.
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FALSE. only mRNA is translated. all others are functional
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is RNA complementary or identical to the template? to the nontemplate?
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complementary to template
identical to lagging |
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how does RNA pol know which is template
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pronoter region where RNA pol binds
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describe the orientaiton of a gene
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promoter has specific seq that RNA pol can recognize
+1 is start of transcription + is anything downstream |
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describe bacterial RNA po
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holoenzyme
a2 b b' w and sigma |
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describe the prok promoter
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-10 -35 pribnow box
consensus sequences determines template and its orientation |
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what does consensus mean
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most frequent promoter seq found therefore promoter will be very similar througout but outside of -10 -35 will vary greatly
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how many nucleotides does RNA pol lay
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8 to 10
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which termination technique depends on sequences in the transcript
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both rho and rho indep
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what follows the hairpin in termination
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rich A region
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how does rho work
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it is a helicase that unwinds RNA pol from the DNA and txn stops
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how many RNA pols are there in euk
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three
I II III |
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compare RNA pol I II III
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rRNAs
mRNA snRNA tRNA 5sRNA |
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txn factor 2 =
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RNA pol II
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is TATA in prok or euk
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euk
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compare enhancers and promoters
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orientation independent. orientation front and back.
can be up or down and far away 50kb away. must be directly upstream of start of txn. where txn happens. affect rate of txn |
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Is the DNA of a gene colinear with the protein
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NO, RNA has sequences that are removed during mRNA maturation
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how do we know that genes are NOT colinear with protein
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make ssDNA and remove RNA secondary structures.
Renature. RNA hybride to DNA but DNA moved out so seq were missing from RNA |
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why does the 7mG cap help protect from nucleases
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normally 5-> 3 but now 3'OH is out of place and nuclease won't break it
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what is the function of the 3' tail
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protection
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splicesosome is made of function _RNAS
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sn
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are introns removed or kept
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removed!
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number of ____ will correspond to mRNA size whcih is smaller than gene size
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introns
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describe mRNA
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5'UTR
ORF 3'UTR promoter and UTR where ribosome may bind |
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what happens during maturation of pre mRNA to mRNA
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only in euk
1. 5' cap protects mRNA from degredation 2. splicing removes introns 3. polyadeylation protetive involved in mRNA stability |
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what are two more methods of variation
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alternative splicing
alternative adenylation |
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t or f. RNAs that are not translated are also processed.
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TRUE ex. tRNA adds special modified nucleotides and sometimes is spliced (euk only)
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how are rRNAs processed
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large precursors are cleaved into pieces
RNA is methylated |
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how many combinations for codons are there
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64
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ow many codons are coding
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61
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what does redundant mean
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multeiple codons for the same aa
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what does commaless mean
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no punctuation
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describe the genetic code
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64 combos
61 coding redundant commaless non overlapping |
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what did nirenberg and collegues do
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broke the genetic code by using tRNA aa ribosomes and getting them stuck in filters
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what is wobble
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don't have to have 61 tRNAs because tRNAs can bind to multiple codons
first and second position are solid while third is less adhesive |
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t or f. all proteins start with AUG
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true
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can AUG be an internal coding seq
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yes
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are there tRNAs for the stop codons
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NO they do not code for aa
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