Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Genetik > Rna Processing > Flashcards

Rna Processing Flashcards

1
Q

ribosomal rna

A
  • rRNA
  • bacterial and eukaryotic
  • cytoplasm
    structural and functional components of the ribosome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

messenger rna

A
  • mRNA
  • bacterial and eukaryotic
  • nucleus and cytoplasm
  • carries genetic code for proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

transfer rna

A
  • tRNA
  • bacterial and eukaryotic
  • cytoplasm
  • helps incorporate amino acids into polypeptide chain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

small nuclear RNA

A
  • snRNA
  • eukaryotic
  • nucleus
  • processing of pre-mRNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

small nucleolar RNA

A

-snoRNA
-eukaryotic
- nucleus
- processing and assembly of rRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

small cytoplasmic RNA

A
  • scRNA
  • eukaryotic
  • cytoplasm
  • variable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

MicroRNA

A
  • miRNA
  • eukaryotic
  • cytoplasm
  • inhibits translation of mRNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

small interfering RNA

A
  • siRNA
  • eukaryotic
  • cytoplasm
  • triggers degradation of other RNA molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

RNA processing why

A
  • after transcription, RNA has to be modified before it function
  • it goes from being a primary transcript to mature RNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

RNA processing: tRNA

A
  • trimming at 5’ and 3’ ends, addition of nucleotides at 3’ end
  • splicing of introns if present, by protein not snRNA spliceosomes)
  • base modifications by specialized tRNA-modifying enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

RNA processing: rRNA in prokaryotes

A
  • extensive processing
  • methylation of bases and 2’-OH or ribose
  • cut and trimmed into smaller pieces (16S, 23S, 5s)
  • often also contains sequences for tRNAs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

RNA processing: rRNA in eukaryotes

A
  • primary 45S rRna transcript is exensively processed
    -extensive methylation of bases and 2’OH of ribose
  • cut and trimmed into smaller pieces (28s, 18s, 5.8s)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

snoRNAs

A
  • small nucleolar RNAs
  • help cleave and modify eukaryotic rRNA and assemble them into mature ribosomes
  • base pairs with the region where the modification will take place
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

mRNA processing: eukaryotes

A

pre-mRNAs are modified in three ways
1. 5’ cap
2. splicing
3. cleavage at 3’ and adding polyA tail

  • occurs in the nucleus
  • mRNA is then exported out of the nucleus and translated by the ribosomes in the cytoplasm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

mRNAs can be further modified

A
  • additional methylation of bases
  • RNA editing (rare)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

5’ cap

A
  • 7-methyl Guanosine attached to the 5’most nucleotide
  • 2’OH of nucleotides 1 and 2 can be methylated but it’s not necessary
17
Q

Addition of 5’cap

A
  • occurs soon after transcription starts
  • phosphorylated CTD (of RNA polI) recruits capping enzymes
  • above-mentioned recognizes the growing 5’ end
  • gamma phosphate of residue 1 removed
  • GTP is added in a 5’-5’ bond while releasing PPi
  • guanine base of cap is methylated on N7
  • possible further modifications
18
Q

3’ cleavage

A
  • requires protein complex containing CPSF, CstF, cleavage factors (CFI, CFII), PolyA polymerase (PAP), polypeptides
  • CPS binds to AAUAAA sequence, CstF binds to U-rich sequence -> loop formation
  • mRNA I cleaved between the two sequences -> unknown mechanism
  • 3’ sequences still attached to pol II and binding factors are released
  • 3’ end is degraded and rna pol II gets signal to stop transcribing
18
Q

polyadenyltaion

A
  • adding of polyA tail
  • PolyA polymerase adds 10 As to the new 3’ end after 3’ cleavage
  • PABII binds to polyA tail
  • PABII stimutlstes PAP to add even more A
  • whole polyA is Ultimatlely coveverd by PABII
19
Q

processing or mRNA without polA tail

A
  • lack polyA tail but still get processed on the 3’ end
  • have a hair pin before cleavage site and a consensus sequence downstream
  • protein binds to hairpin and recruits U7 snRNP that interacts with consensus sequence and cleaves
19
Q

exons

A

parts of the genes that are transcribe and found in mature RNA
can be protein-coding or non-coding

20
Q

introns

A

sequences between exons that are transcribed but not found in mature RNA
mostly found in eukaryotic genes coding for mRNAs
are removed by splicing

21
Q

group I intron

A
  • rRNA regions
  • self-splicing
22
Q

group II intron

A
  • protein-encoding genes in mito. and chloro
  • self-splicing
23
Q

nuclear pre-mRNA

A
  • protein-encoding genes in nucleus
  • spliceosomal
24
Q

tRNA

A

-tRNA genes
- enzymatic

25
Q

what is needed for splicing (cis)

A
  • 5’ splice site: starts with GU
    -3’ splice site: ends with AG
  • branch point A
26
Q

what is needed for splicing (trans)

A
  • 5’ splice site: starts with GU
    -3’ splice site: ends with AG
  • branch point A

plus
- snRNPs
- additional prtoens

27
Q

snrnps

A
28
Q

splicing principle

A
  • pre mRNA splicing is catalysed by spliceosome
  • carried out in two transesterification reactions
  • results in fusion of two exons and release of intron
29
Q
A

Genetik (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions