Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Microbiology > Microbial Transcription and Translation > Flashcards

Microbial Transcription and Translation Flashcards

1
Q

RNA polymerase in prokaryotes is comprised of what two parts?

A

Core + sigma factors

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

Sigma factors

A

Proteins of RNA polymerase that direct the core to promoters

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

Two examples of sigma factors and their functions

A

Sigma 70: housekeeping

Sigma S: activated during stationary phase

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

What is the antibiotic that targets bacterial RNA polymerase?

A

Rifampin

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

Transcription generates what 3 types of RNA?

A

tRNA (transfer RNA)
rRNA (ribosomal RNA)
mRNA (messenger RNA)

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

tRNA function

A

Carries amino acids during protein synthesis

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

rRNA function

A

Component of ribosomes

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

mRNA

A

Template for protein synthesis

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

RNA uses what type of sugar instead of deoxyribose (used in DNA)?

A

Ribose

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

What base replaces thymine in RNA?

A

Uracil

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

Is RNA usually single stranded or double stranded?

A

Single stranded

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

Promoter region of DNA consists of what 3 sites?

A

+1

  • 10
  • 35
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

+1 site

A

Promoter site where transcription is started

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

-10 site

A

Promoter site where RNA polymerase binds

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

-35 site

A

Promoter site that RNA polymerase initially recognizes

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

What is the name of the DNA strand that directs synthesis of RNA? What is the name for the other strand?

A

Template strand directs RNA synthesis

Coding strand is other strand

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

Terminator

A

Sequence of DNA that signals RNA polymerase to stop transcription

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

Start codon

A

Portion of mRNA that signals beginning of translation

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

Stop codon

A

Portion of mRNA that signals ending of translation

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

Shine-Dalgarno sequence

A

Portion of mRNA that aligns ribosome with RNA for translation

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

What enzyme opens and unwinds DNA in transcription? Does it require a primer?

A

RNA polymerase

Doesn’t require a primer

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

In what direction does RNA polymerase move along the template strand? In what direction is mRNA synthesized?

A

RNA polymerase moves from 3’ to 5’

mRNA is synthesized from 5’ to 3’

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

When does the sigma factor leave RNA polymerase?

A

After transcription is initiated

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

Two types of terminators

A

Rho-independent

Rho-dependent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Rho-independent terminator: what structure does it encode, what does it do
Encodes RNA stem loop structure | Causes RNA Pol release
26
Rho-dependent terminator: what does it do, what does Rho protein do
Causes RNA Pol to pause | Rho binds RNA then moves towards RNA Pol, causing it to release
27
Bacteria use two-component signal transduction systems to control what in response to what?
Gene transcription | Environment
28
What are the two components of two-component signal transduction systems?
Sensor kinase + kinase domain | Response regulator
29
Sensor kinase: where is it located, what does it do
Part is embedded in plasma membrane, other part is inside of cell Can sense different environmental conditions such as temperature
30
Kinase domain: what is it connected to, where is it located, what does it do
Connected to sensor kinase in cytoplasm | Autophosphorylates at conserved histidine using ATP in response to certain environmental conditions
31
Response regulator: what is transferred onto it and at what amino acid, what does it do when phosphorylated
Phosphate from sensor is transferred onto aspartate of response regulator When phosphorylated, binds to promoter region of gene, activating transcription
32
In eukaryotes, where does transcription occur?
Nucleus
33
In eukaryotes, how many RNA polymerases are used?
3
34
Instead of sigma factors, what do eukaryotes use for transcription?
Transcription factors
35
TATA box
Promoter element of transcription in eukaryotes
36
What process occurs in eukaryotes to remove introns?
RNA splicing
37
In eukaryotes, what is done with mRNA that is not commonly done in prokaryotes?
Modification
38
Capping
Modification of mRNA in eukaryotes | Methylguanosine is added at 5' end
39
Polyadenylation
Modification of mRNA in eukaryotes | Adenine nucleotides are added at 3' end (tail)
40
Purpose of capping and polyadenylation in eukaryotes
Stability of mRNA | Involvement in translation initiation
41
Translation has what 2 requirements?
Ribosomes | Energy (GTP and ATP)
42
2 subunits of bacterial ribosome
30S | 50S
43
30S subunit of bacterial ribosome: how many proteins? What rRNA?
21 proteins | 16S rRNA
44
50S subunit of bacterial ribosome: how many proteins? What rRNAs?
34 proteins | 23S and 5S rRNA
45
23S rRNA has what type of activity?
Enzymatic
46
Ribozyme
RNA with enzymatic activity
47
Peptidyltransferase: what rRNA, what does it do
Utilized by 23S rRNA to catalyze peptide bonds between adjacent amino acids
48
16S rRNA: function, sequence is complementary to what mRNA sequence
Aligns mRNA with ribosome | Sequence is complementary to Shine-Dalgarno sequence
49
Codon features how many nucleotides?
3 (triplet)
50
How many codons total?
64
51
How many codons specify amino acids?
61
52
Difference between sense and nonsense codons
Sense codons code for amino acids, but nonsense codons trigger cessation of translation
53
How many codons are stop codons? Stop codons are also referred to as what?
3 | Nonsense codons
54
Degeneracy of codons
Multiple codons can encode the same amino acid
55
What is the start codon's sequence? What does it code for?
AUG | Codes for methionine
56
What are the 3 stop codons?
UAA UAG UGA
57
tRNA molecule: what shape?
Clover leaf
58
2 functional regions of tRNA
3' end | Anticodon
59
3' end of tRNA: what enzyme attaches what here?
Synthetase enzyme attaches an amino acid here
60
Anticodon: complementary to what, what does this enable it to do
Complementary to corresponding codon in mRNA | Enables it to hydrogen bond to mRNA codon
61
Translation occurs at what organelle?
Ribosome
62
3 stages of translation
Initiation Elongation Termination
63
30S subunit contains what 3 sites?
A, P, E
64
A site of 30S subunit: what does it stand for, what does it do
Acceptor/aminoacyl site | Accepts tRNA
65
P site of 30S subunit: what does it stand for, what does it do
Peptidyl site | tRNA binds to mRNA
66
E site of 30S subunit: what does it stand for, what does it do
Exit site | tRNA leaves ribosome from here
67
Start codon in translation: first __-____
f-Met (formylmethionine)
68
Step 1 of translation inititation
16S rRNA in the ribosome hybridizes with Shine-Dalgarno sequence of mRNA, aligning mRNA with ribosome
69
Step 2 of translation initiation
tRNA with formylmethionine binds to the start codon in the P site
70
Step 1 of translation elongation
Next tRNA plus amino acid binds to A cite
71
Designation for tRNA + amino acid
Charged
72
Insertion of tRNA into A site requires what?
GTP
73
Step 2 of translation elongation
Peptide bonding joins amino acids, catalyzed by 23S rRNA
74
Step 3 of translation elongation
Ribosome moves 1 codon along mRNA
75
Step 4 of translation elongation
Empty tRNA moves from P to E site
76
Translation termination: what two things happen?
1. Any one of 3 stop codons (UAA, UAG, or UGA) is reached | 2. Release factors cleave and release polypeptide
77
In prokaryotes, transcription and translation are often _____. What enables this?
Coupled | Lack of nucleus in prokaryotes

Microbiology (24 decks)

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