Brainscape's Knowledge GenomeTM

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


See full index

Cell Biology Unit 2 > Topic 3, Lecture 3 > Flashcards

Topic 3, Lecture 3 Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What must an mRNA have to be considered export-ready?

A

Poly-A binding proteins, cap binding complex, exon junction complexes, absence of snRNPs

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

Initiation factors for protein synthesis

A

eIF4G and eIF4E

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

eIF4G

A

Scaffolding protein, binds to mRNA allowing recruitment of ribosomes and translation initiation

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

eIF4E

A

Cap-binding protein, binds to helicase and eIF4G

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

Where is the start codon?

A

Usually within 100 nucleotides of the 5’ cap

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

Kozak Sequence

A

ACCAUGG, first A and last G help identify the initiating AUG

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

Leaky Scanning

A

Two different proteins with different N-termini from the same mRNA

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

IRES

A

Internal Ribosome Entry Site

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

Polysome

A

Polyribosome, a cluster of ribosomes held together by a strand of mRNA that each ribosome is translating

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

How is the steady-state level mRNA is determined?

A

By the rate of transcription and the rate of degradation

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

Relationship between mRNA stability and steady state level

A

mRNA with a long half-life (slow degradation) can result in translation and protein production long after transcription ceases and mRNA with a short half-life (rapid degradation) can result in rapid changes in protein concentration

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

What is the advantage of a long half-life?

A

If we needed a consistent concentration of the same gene, we wouldn’t have to keep transcribing it over and over

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

What is the advantage of a short half-life?

A

If we needed a high concentration of a protein for a very short length of time

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

How is mRNA with a short half-life regulated?

A

At the level of transcription

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

What is the typical half-life of mRNA?

A

30 minutes

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

mRNA degradation pathways

A
  1. gradual poly-A shortening
  2. decapping for rapid 5’-to-3’ degradation OR continued 3’-to-5’ degradation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Decapping Pathway (deadenylation-independent)

A

Decapping, exonucleolytic decay

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

Deadenylation-dependent pathways

A

Poly(A)-shortening, decapping OR exonucleolytic decay by exosome

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

Exosome

A

Enzyme that degrades

20
Q

Endonucleolytic pathway

A

Endonucleolytic cleave, exonucleolytic decay by exosome

21
Q

Deadenylase

A

Rapidly eats away at the poly-A tail in the 3’ tp 5’ direction

22
Q

Ferritin

A

Iron-binding protein, prevent accumulation of toxic levels of iron within the cell, produced at high concentration of iron

23
Q

Transferrin Receptor

A

Binds to transferrin and brings iron into the cell, produced at low concentration of iron

24
Q

Cytosolic Aconitase

A

Binding protein for transferrin and ferritin mRNA

25
Q

When do we control ferritin and transferrin production?

A

Post-translation

26
Q

DCP 1

A

Decapping enzyme, lots of degradation

27
Q

Argonaute

A

Slicing enzyme, RNA becomes unstable because of endonucleolytic cleavage

28
Q

P-bodies

A

Dynamic structures composed of large assemblies of mRNA and mRNA degrading enzymes

29
Q

Stress granules

A

Contain translation initiation factors, poly-A binding proteins, small ribosomal subunits, and mRNA

30
Q

Three classes of noncoding RNAs that engage in RNA interference

A

microRNAs (miRNA), small interfering RNAs (siRNA), piwi-interacting RNAs (piRNA)

31
Q

Why does RNA Polymerase II make mRNA and the RNAs that degrade?

A

Dimmer switch

32
Q

miRNA

A

Guides that bring target mRNA into contact with exonucleases

33
Q

Cropping

A

Happens in the nucleus, cuts off cap and poly-a tail

34
Q

Dicing

A

Chops off the loop

35
Q

Slicing

A

Slices to promote degradation

36
Q

RISC

A

RNA induced silencing complex

37
Q

Extensive Base Pair Matching

A

Slicing and RISC reusable

38
Q

Less Extensive Base Pair Matching

A

Causes rapid translational repression, deadenylation, and eventual degradation

39
Q

RITS

A

RNAi induced transcriptional silencing, complex recruits proteins that modify histones and direct the formation of heterochromatin

40
Q

siRNAs

A

Short inhibitory RNAs, one of the siRNAs binds to the RITS

41
Q

What happens when siRNAs bind to the RITS?

A

Leads to histone methylation, DNA methylation, and transcriptional repression, cotranscriptional

42
Q

Long non-coding RNA

A

Scaffolds

43
Q

Anchor Proteins

A

Holes in the wall that hang onto mRNA

44
Q

Directed transport on cytoskeleton

A

Proteins act as trains on a track to transport proteins

45
Q

Random diffusion and trapping

A

Diffusion of mRNA all over cytoplasm

Cell Biology Unit 2 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions