Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

COB Molecular > Lec 9. Protein synthesis 2. RNA Maturation and Versatility > Flashcards

Lec 9. Protein synthesis 2. RNA Maturation and Versatility Flashcards

1
Q

What are the steps for mRNA processing?

A

Capping proteins then splicing proteins then polyadenylation proteins

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

Why is RNA sticky?

A

Nitrogenous bases want to base pair with respective complementary bases, can form 4 secondary structures that can become binding sites for proteins

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

What are the 4 secondary structures for RNA?

A

Three-nucleotide bulge, four-stem junction, hairpin loop, pseudoknot

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

what is the 5’ cap?

A

An upside down and backwards G with an extra methyl group at the 5’ end of an RNA*

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

What does the 5’ cap do?

A

Resistant to digestion by nucleases, serves as a recognition site for CBC proteins (Cap binding complex).

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

What do CBC proteins do?

A

Initiate splicing and polyadenylation, direct mature mRNA through the nuclear pores and recruits elFs once in cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 4 mRNA processing splicing types?

A

Group I introns, Group II introns, Spiceosomal introns, and tRNA introns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Who has group I introns?

A

Prok, euk, and organelles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where are group I introns usually found?

A

In rRNA genes of euk.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How are Group I introns removed?

A

Self-catalyzed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Once Group I introns are removed what are the results?

A

Either linear or circularized introns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which of the 4 mRNA processing splicing types is most prevalent in humans?

A

Group I introns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Who has Group II introns?

A

Prok and euk organelles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How are Group II introns removed?

A

Self-catalyzed, some require a protein helper in vivo.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the result once Group II introns are removed?

A

Lariot structures that are precursors to spliceosomal introns.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Who has spiceosomal introns?

A

Euk only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How are Spiceosomal introns removes?

A

Protein-mediated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the end result once Spiceosomal introns are removed?

A

Lariat structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Who has tRNA introns?

A

Euk and their organelles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How are tRNA introns removed?

A

Protein-mediated. The intron sits across the anticodon, in order to remove the intron we need to split the tRNA in half and stick it back together.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Alternative splicing is a way to

A

increase genetic diversity without a permanent change to the DNA sequence*

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is polyadenylation?

A

200 A’s at the 3’ end of an RNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does this polyadenylation do?

A

Define the exact 3’ end of the RNA, it is also a binding spot for PABS (PolyA binding proteins).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What do PABPS do?

A

Resistant to digestion by nucleases, can bind to translation initiation factors (elFs) to circularize the mRNA and start translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Pertaining to polyadenylation, what does co-transcriptional recruitment of CPSF to polyadenylation signal site do?
Our specificity factor, where we stop our DNA.
26
Where does CstF bind?
DSE (downstream element site)
27
What do CPSF and CstF do?
Interact through this complex of proteins and basically expose this site (NN) to be cleaved as our absolute end of our mRNA, so we need an ENDO nuclease to come in and clip at the NN.
28
What does Poly-A Polymerase (PAP) do?
Adds polyA tail
29
What does Poly-A Binding Proteins (PABPs) do?
Coat the polyA tail, will act with elFs and loop around the end of mRNA and help initiate translation
30
What is the difference between coding and noncoding RNAs?
Coding RNAs are coding for protein, if we are not coding for protein we are noncoding RNA.
31
What is the only coding RNA?
mRNAs
32
What is the function for mRNAs?
code for proteins
33
What is the function for rRNAs?
form basic structure of the ribosome and catalyze protein synthesize
34
What is the function for tRNAs?
central to protein synthesis as adaptors between mRNA and amino acids
35
What is the function for snRNAs?
Nuclear processes, splicing of pre-mRNA
36
What is the function for snoRNAs?
help to process and chemically modify rRNAs
37
What is the function for miRNAs?
regulate gene expression by blocking translation of specific mRNAs and cause their degradation
38
What is the function for siRNAs?
turn off gene expression by directing the degradation of selective mRNAs and the establishment of compact chromatin structures
39
What is the function for piRNAs?
Piwi-interacting RNAS bind to piwi proteins and protect the germ line from transposable elements
40
What is the function for lncRNAs?
Scaffolds, regulate diverse cell processes including x-chromosome inactivation
41
Where are rRNAs made?
Nucleolus
42
Where are snRNAs and snoRNAs matured and recycled in?
Cajal bodies
43
What are speckles?
Stockpiles of snRNAs and other processing factors
44
Where are snRNAs found?
Nucleus
45
snRNAs are transcribed by what?
RNA pol I & II
46
What is the size catagory for snRNAs?
Mid-range
47
What are the role of snRNAs?
splicing out the introns
48
Where are snoRNAs found?
Nucleolus
49
snoRNAs are transcribed by what?
RNA pol II(meaning they get a cap n tail but dont need them and actually need to remove them to be functional)
50
What is the size category for snoRNAs?
mid-range
51
What is the role of snoRNAs?
modification of nucleic acids (tRNA,rRNA, and snRNAs), can be cleaved down to miRNAs or piRNAs.
52
siRNA, miRNA, piRNAs are transcribed by what?
RNA pol II
53
What is the size category for siRNA, miRNA, piRNAs?
Small
54
What is the role of miRNAs?
block translation by degrading RNAs
55
What is the distinguishable feature of miRNAs?
Hairpin with a bulge
56
What is the role of siRNAs?
Block translation by degrading RNAs, block transcription by promoting heterochromatin
57
What is the distinguishable feature of siRNAs?
No bulge, no hairpin, just a ds RNA
58
What are the steps to transcriptional silencing by siRNAs?
DCr1 cleaves ds RNa and makes siRNAs, RITS comes in with HMT to methylate.
59
What does transcriptional silencing by siRNAs require?
sequence homology.
60
What does transcription silencing by siRNAs do?
spreads a methyl mark that signals for heterochromatin. Happens on nucleus
61
What are piRNAs role?
Makes short RNA and then silences transposons by methylating their DNA by interacting with PIWI
62
lncRNAs are transcribed by what?
RNA pol II
63
What is the size category for lncRNAs?
large
64
What is the role of lncRNAs?
activating or inhibiting, scaffold for proteins or bind directly to DNA/RNA
65
What are the 4 types of lncRNAs?
Signal,decoy,guide, scaffold
66
What does the signal lncRNA do?
indicated transcriptional activity
67
What does the decoy lncRNA do?
removes other regulatory RNAs
68
What does the guide lncRNA do?
directs localization of RNA-protein complexes
69
What does the scaffold lncRNA do?
structure
70
What is an example of signal lncRNA?
Xist and Tsix (complementary to each other)
71
What does Xist do?
when expressed coats x chromosome and thus inactivating it , making it a bar body
72
What is an example of decoy lncRNA?
Gas5
73
What does Gas 5 do?
Binds to glucocortcoid receptor, once bound its a decoy. Meaning that the actual gluco cant bind to the receptor and cant activate that gene
74
What is an example of a guide lncRNA?
HOTAIR
75
What does HOTAIR do?
Localizes the repressive complex (PRC2). PCR2 is a histone methyl transferase that leaves a repressive mark.
76
What does over expression of HOTAIR uually indicate?
Cancer

COB Molecular (36 decks)

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