Term
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Definition
- micro RNA - 22-24 nucleotides - controls gene expression |
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Term
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Definition
- small nuclear RNA - needed for mRNA maturation - part of the spliceosome |
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Term
What is the function of hnRNA? |
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Definition
- heterogeneous nuclear RNA - intermediate form of mRNA ( - the "pre-mRNA" processed to make mRNA |
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Term
How many RNA Polymerases are there in eukaryotes? |
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Definition
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Term
What are the names of all the polymerases in eukaryotes and what do they do? |
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Definition
Pol 1: transcribes rRNA genes (5.8S, 18S, and 28S) Pol 2: transcribes mRNA genes Pol 3: transcribes tRNA genes and the 5S rRNA gene |
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Term
What is needed for mRNA initiation? |
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Definition
The formation of a basal transcription initiation complex (several TFIIs) which bind at the TATA box |
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Term
What facilitates the formation of the basal transcription initiation complex? |
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Definition
The binding of proximal promoter elements and enhancer elements |
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Term
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Definition
- by the enzymatic, cotranslational addition of a 7-methyl-G cap and a poly-A tail |
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Term
What is polyadenylation signal? |
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Definition
AAUAA, the poly-A tail is added downstream of this |
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Term
What is added right after the polyadenylation signal? |
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Definition
~200 AMPs by poly(A) polymerase |
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Term
What two things help protect mRNA from degradation and facilitate mRNA translation? |
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Definition
The addition of the 7MG cap, and the poly-A tail |
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Term
In the event that mRNA is edited after synthesis, name what happens, and two ways it can be done? |
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Definition
The insertion or deletion of specific nucleotides using: 1) a guide RNA (trypanosome mitochondria) 2) base modification (C-U editing) |
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Term
True or False: All mRNA gets edited |
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Definition
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Term
How are tRNA precursors processed in yeast? |
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Definition
by endonucleolytic cleavage and ligation |
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Term
How are Tetrahymena mRNA precursors processed? |
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Definition
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Term
How are intervening sequences removed in Tetrahymena? |
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Definition
Cutting and rejoining by and RNA-catalyzed mechanism |
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Term
How are introns removed from mRNA precursors in eukaryotes and prokaryotes? |
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Definition
Sliceosome mediated splicing |
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Term
What happens after introns are removed? |
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Definition
Exons are spliced together |
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Term
What is the result of splicing together exons? |
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Definition
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Term
What are spliceosomes composed of? |
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Definition
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Term
What is contained in an snRNP? |
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Definition
A specific snRNA (U1, U2, U3, U4, U5, U6) |
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Term
What do each of the following specific snRNPs recognize? U1, U2, U5 |
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Definition
U1 - the 5' splice site U2 - branch point A residue U5 - recognizes the 3' slice site |
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Term
How is a lariat structure produced? |
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Definition
Cleavage at the 5' splice site, and joining the intron end to the branch point |
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Term
What happens after the lariat structure is produced? |
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Definition
It is removed by cleavage at the 3' splice site |
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Term
What is the final step of RNA splicing? |
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Definition
Joining the 5' exon to the 3' exon |
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Term
How can the coding potential of a gene be increased? |
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Definition
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Term
What would a mutation affecting a splice site recognition sequences cause? |
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Definition
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