Brainscape's Knowledge GenomeTM

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


See full index

Molecular Biology. > Translational Regulation. > Flashcards

Translational Regulation. Flashcards

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

Define an oocyte?

A

An unfertilised egg.

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

Define oogenesis?

A

The generation of an oocyte.

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

What does the abbreviation UTR stand for?

A

An abbreviation for an untranslated region of DNA.

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

How many main mechanisms are involved in the regulation of gene expression in eukaryotes?

A

At least 6.

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

At what stage does the majority of the regulation of gene expression occur in eukaryotes?

A

At the transcriptional level.

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

Other than during transcription, at what other times can the regulation of gene expression occur in eukaryotes?

A

During RNA processing.

At multiple points between the transport of mRNA to the cytoplasm and post-transcriptional modification.

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

What is translational regulation occur in eukaryotes?

A

It is the various methods that the cell can control the formation of a protein from mRNA.

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

What section of mRNA is used for recognition by the ribosomes?

A

The 5 prime cap.

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

What are the poly-A tails used for on an mRNA molecule?

A

To prevent degradation by an endonuclease.

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

Are the 5 prime cap and poly-A tails examples of post-translational regulation?

A

Yes.

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

Why are the 5 prime cap and poly-A tails examples of post-translational regulation?

A

Because their presence will determine whether transcription occurs.

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

What post transcriptional method can determine the type of protein that is made from an mRNA strand?

A

RNA splicing.

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

What are the global effects of translational regulation?

A

When almost every mRNA in the body is affected.

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

What factor usually causes the global effects of translational regulation?

A

The rate limiting factors that are involved in translation or the availability of a substrate.

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

What are the specific effects of translational regulation?

A

They affect a particular mRNA via different mechanisms.

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

What 3 factors can cause specific effects of translational regulation?

A

Different responses to nutrients.

Different developmental cues.

A physical change within the cell such as cell polarity.

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

What factors about mRNA will lead to translational modification?

A

Intrinsic factors that are within the mRNA or have arisen due to modifications to the molecule.

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

Give an example of an intrinsic factor within mRNA that can lead to translational modification?

A

Hairpin loops which can interact with and be modified by various proteins.

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

The different forms of hairpin loops on an mRNA molecule will determine what?

A

It will determine the different proteins that can bind to it and this will control how translation occurs.

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

What 4 things is the translation of mature mRNA is regulated by?

A

Sequence elements within the mRNA.

Which version of an mRNA transcript is translated.

Modifications to the mRNA.

mRNA stability.

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

Do oocytes contain any mRNA?

A

Yes.

They contain mRNA transcripts so that proteins can be made immediately after fertilisation occurs.

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

How are the mRNA transcripts in the oocyte kept silent until fertilisation occurs?

A

By masked messages which are small ribonucleoproteins called maskin proteins.

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

How do maskin proteins keep the oocyte silent until fertilisation occur?

A

By preventing the mRNA transcripts from attaching to the ribosomes until after fertilisation has occurred.

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

How are the maskin proteins removed from the oocyte once fertilisation has occured?

A

Fertilisation induces intracellular ionic changes which leads to the release of the maskin proteins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What will the stored mRNA’s in the oocyte do once the maskin proteins have been released?

A

They can bind to the ribosome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What mRNA’s will be immediately translated during oogenesis?

A

The mRNA’s that are responsible for the growth and maturation of the oocyte.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How are the mRNA’s that are responsible for the growth and maturation of the oocyte differentiated from other mRNAs during oogenesis?

A

They have long poly-A tails.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How are the mRNA’s that are stored in the oocyte differnetiated from the mRNA’s that are used during oogenesis?

A

They have their poly-A tails cut off and will have their translation blocked.

The mRNA’s that are used during oogenesis have long poly-A tails.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What happens to the poly-A tails of the mRNAs that code for oocyte growth when the oocyte has matured and been fertilised?

A

The poly-A tails will be removed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What happens to the stored mRNA’s once the oocyte is mature and fertilisation has occurred?

A

They will receive a long poly-A tails allowing these mRNAs to be translated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the process of selective poly-adenylation?

A

The method of cleaving poly-A tails on specific mRNA’s which will inhibit translation.

32
Q

What intrinsic factor in the mRNA will signal for poly-adenylation to occur?

A

A cytoplasmic poly-adenylation element (CPE) in the 3-trailer marks mRNAs to be poly-adenylated at fertilisation.

33
Q

What will bind to the short poly-A tails on the stored mRNA’s in the oocyte?

A

They are bound to maskin proteins and to CPE binding proteins (CPEB).

34
Q

What will activate the the CPE binding proteins on the short poly-A tails of mRNA in the fertilised oocyte?

A

Progesterone.

Progesterone levels are high after fertilisation.

35
Q

How does progesterone activate the CPE binding proteins in the fertilised oocyte?

A

It will activate a kinase enzyme that phosphorylates and activates CPEB.

36
Q

What happens to the CPE binding proteins once they have been activated by the presece of progesterone?

A

The maskin proteins are released and mRNA is poly-adenylated until translation can occur.

37
Q

Where will the PUF proteins bind to on an mRNA transcript?

A

To specific nucleotides in the 3-UTR.

38
Q

What will the presence of the PUF proteins in the 3-UTR of an mRNA molecule prevent?

A

They will prevent poly-adenylation.

39
Q

How can the PUF proteins affect translation?

A

They prevent ribosomal binding by interacting with a sequence on the 5-UTR or with the 7-methylguanosine cap.

40
Q

Will PUF proteins enhance or repress the translation of mRNA?

A

They will repress the translation of mRNA.

41
Q

What area of an mRNA transcript will bind to the ribosome?

A

The 7-methylguanosine cap on the 5-prime end.

42
Q

How is the methyl guanosine cap changed on mRNA’s in the oocyte?

A

Oocyte mRNAs contain an un-methylated guanosine cap.

43
Q

When is the methyl group added to the guanosine cap in the oocyte?

A

After fertilisation has occurred.

44
Q

What enzyme adds the methy group to the guanosine cap of the mRNA’s in the oocyte?

A

7-methyl guanosine transferase.

45
Q

What are the 2 proteins used in fruit fly development that will determine the anterior and posterior regions of the developing fruit fly?

A

BICOID and CAUDAL.

46
Q

What end of the developing fruit fly is determined by the presence of the BICOID protein?

A

The anterior end.

47
Q

What end of the developing fruit fly is determined by the presence of the CAUDAL protein?

A

The posterior end.

48
Q

How do the BICOID proteins prevent CAUDAL mRNA from being translated in the anterior region of the developing fruit fly?

A

The proteins will bind to the CAUDAL mRNA and preventing translation to CAUDAL proteins.

49
Q

Why will BICOID proteins not be translated in the posterior region of the developing fruit fly?

A

The BICOID proteins form a gradient and are in high concentrations in the anterior region.

The BICOID concentration gets lower as it proceeds to the posterior region of the embryo.

50
Q

Is CAUDAL mRNA expressed in a gradient in the developing fruit fly?

A

No.

It is expressed in equal quantities throughout the embryo.

51
Q

Where will BICOID proteins inhibit the translation of CADUAL mRNA?

A

In regions where the BICOID protein is expressed.

52
Q

What region of the developing fruit fly embryo will the translation of CAUDAL mRNA be inhibited in?

A

In the anterior region of the embryo.

53
Q

Where will the CAUDAL proteins be expressed in the fruit fly embryo?

A

In the posterior region.

54
Q

How do BICOID protiens inhibit the translation of CAUDAL mRNA in the fruit fly embryo?

A

They will inhibit the poly-A binding proteins meaning that poly-adenylation will not occur.

55
Q

Where do the BICOID proteins bind to on the CAUDAL mRNA?

A

To specfic sequences in the 3-UTR.

56
Q

Why does the cell not want high concentrations of iron within the cell?

A

As they can act as free radicals.

57
Q

What protein is responsible for stroing iron in the cytosol of the cell?

A

Ferritin.

58
Q

How does ferritin store iron?

A

When free iron is in the cytoplasm ferritin will bind to it and store it.

59
Q

When will the translation of the mRNA that makes the ferritin protein be blocked?

A

Under low iron conditions.

60
Q

Why is the translation of ferritin mRNA blocked under low iron condition?

A

To allow free iron to accumulate in the cell which can then be used for cellular processes.

61
Q

When will the translation of the mRNA that makes the ferritin protein occur?

A

When free iron levels within the cell get too high.

62
Q

Why is ferritin mRNA translated when free iron levels within the cell are high?

A

The ferritin protein can bind to the iron and remove it from the cell.

63
Q

What protein will bring iron into the cell when intracellular iron concentrations are low?

A

Transferrin.

64
Q

When is transferrin mRNA translated?

A

When intracellular iron concentrations are low.

65
Q

Will the mRNA of transferrin ever be blocked?

A

It will be degraded when intracellular iron concentrations are high so that no more iron enters the cell.

66
Q

What are internal ribosomal entry sites (IRES)?

A

They placed on the 5 prime end of viral mRNA instead of a 5 prime cap.

67
Q

Are ribosomes able to translate mRNA that does not have a 5 prime cap?

A

No.

68
Q

How does viral mRNA with an IRES manage to get translated if it does not have a 5 prime cap?

A

The IRES mimics the 5 prime cap and fools the ribosomes into producing viral proteins.

69
Q

Do any human mRNA’s contain an IRES?

A

Some mRNA’s that code for proteins involved in apoptosis will also contain an IRES.

70
Q

Will an IRES enhnace or repress the translation of mRNA?

A

It will enhance translation.

71
Q

Whe does the process of differential proteolytic cleavage occur?

A

It is part of the the post translational processing of proteins and occurs after translation has occurred.

72
Q

Differential proteolytic cleavage commonly occurs in which gland of the body?

A

In the pituitary gland, where different proteins will be expressed in different lobes of the pituitary.

73
Q

What protein often undergoes differential proteolytic cleavage in the pituatary gland?

A

The melanocyte stimulating hormone (MSH).

74
Q

What 2 proteins will MSH be cleaved to form via differential proteolytic cleavage in the anterior domain of the pituitary gland?

A

The N-terminal fragment.

The B-lipoprotien.

75
Q

How is MSH cleaved via differential proteolytic cleavage in the intermediate lobe of the pituitary gland?

A

MSH is cleaved to form the N-terminal fragment and the B-lipoprotien.

76
Q

How is the N terminal fragment cleaved by differential proteolytic cleavage after cleavage of the MSH in the intermediate lobe of the pituitary gland?

A

The N-terminal fragment is cleaved to form the adrenocorticotropic hormone.

The adrenocorticotropic hormone can be cleaved again to produce a polypeptide sequence and the a-MSH protein.

77
Q

How is the B-lipoprotein cleaved by differential proteolytic cleavage after cleavage of the MSH in the intermediate lobe of the pituitary gland?

A

It can be cleaved to form the B endorphin.

Molecular Biology. (22 decks)

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