Brainscape's Knowledge GenomeTM

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


See full index

BIOL 112 > UNIT 3 > Flashcards

UNIT 3 Flashcards

1
Q

What is transcription?

A

The process of copying DNA to RNA

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

What is translation?

A

The process of synthesizing proteins from mRNA

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

List the eukaryote:

Chromosome structure
Site of transcription
What is the promoter structure?
What are the proteins involved contacting the promoter?
Is splicing (removal of introns) required?
Capping and tailing of mRNA?
Site of translation
Can translation occur while transcription is still occurring?

A 
Contains histones (nucleosomes)
Nucleus
TATA box, 25 bp upstream
General transcription factors
Tata Binding Protein (TBP)
Yes
Yes
Cytoplasm 
No
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

List the bacteria:

Chromosome structure
Site of transcription
What is the promoter structure?
What are the proteins involved contacting the promoter?
Is splicing (removal of introns) required?
Capping and tailing of mRNA?
Site of translation
Can translation occur while transcription is still occurring?

A 
Does not contain histones
Cytoplasm 
-35 box and -10 box
Sigma
No
No
Cytoplasm
Yes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the site of transcription for eukaryote/bacterial cells?

A

eukaryote: TATA box
bacterial: -10 box and -35 box

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

Transcription factors only bind specific DNA sequences. What part of the DNA molecule would you predict is most important for specific interactions between a transcription factor like Sigma and the promoter sequence it binds?

A

the bases

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

What determines where the E. coli RNA Polymerase initiates transcription?

A

The binding of the sigma subunit to the DNA binding sequences upstream of the transcription start site

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

The fact that translation is not simultaneous with transcription in eukaryotes is primarily due to:

A

the fact that the processed mRNA needs to be exported to the cytoplasm for translation

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

Which components come together to form the initiation complex so that transcription can begin in eukaryotic cells?

A

general transcription factors, RNA POL, TATA binding polymerase

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

What would happen to an mRNA strand in a eukaryotic cell if during RNA processing the poly A tail is not added?

A
  • The mRNA strand would not be able to leave the nucleus as the tail is necessary to pass through the nuclear membrane.
  • The mRNA strand would no longer be protected by the poly A tail and would be more easily degraded by ribonucleases.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the function of aminoacyl-tRNA synthetases?

A

They catalyze the covalent attachment of an amino acid to the correct tRNA.

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

MalT is a ______ regulator of the malPQ operon

A

positive

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

LacI is a _______ regulator of the LacYZ operon

A

negative

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

the lac operon:

  1. Regulates breaking down of:
  2. What binds to the operator & when does this occur?
  3. High levels of what substance affects the operon, and how?
  4. Is this positive regulation or negative regulation? Why?
A
  1. lactose
  2. The LacI repressor protein binds to the operator when lactose levels in the cells are low.
  3. High levels of lactose induce the operon, by binding to 4. LacI and removing its repression.
  4. This is negative regulation because the repressor protein, LacI, inhibits the gene expression.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

the Mal operon:

  1. Regulates breaking down of:
  2. What binds to the operator & when does this occur?
  3. High levels of what substance affects the operon, and how?
  4. Is this positive regulation or negative regulation? Why?
A
  1. maltose
  2. The MalT-maltose activator complex binds to the operator when maltose levels in the cells are high.
  3. High levels of maltose induce the operon, by binding to 4. MalT and enabling its activation function of the operon.
  4. This is positive regulation because the activator protein, MalT, enhances/promotes gene expression.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

T or F: Each protein coding sequence within that operon would have its own start and stop codon

A

true

17
Q

A mutation in MalT (the regulator) caused a change in its tertiary structure. The mutated protein can bind to the operator without binding maltose. What would be the result?

A

MalPQ would be expressed all the time

18
Q

When lactose is present in the growth medium, LacI binds to the DNA with very ___ affinity and the operon is transcribed at___ levels.

A

low, high

19
Q

What is the fundamental difference between the regulatory proteins LacI and MalT?

A

MalT binds DNA efficiently and LacI does not

20
Q

Which of the following statements about regulation of the lac operon of E. coli are correct? CHOOSE ALL THAT APPLY
A. The LacI protein binds to the operator and inhibits transcription of the lac operon.
B. When grown in media with no lactose, E. coli produce high levels of lacZY mRNA.
C. The LacI protein will change shape in the presence of lactose.
D. Cells that contain a mutant LacI protein that cannot bind lactose are unable to metabolize lactose.
E. When cells are grown in medium that contains lactose, the LacI protein, after binding to lactose, will bind near the promoter for the lac operon.

A

ACD

BIOL 112 (5 decks)

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