exam three (microbial genetics) Flashcards

(64 cards)

1
Q

small, self replicating extrachromosomal genetic elements

A

plasmid

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

all genetic elements present in an organism

A

genome

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

streptococcus pneumoniae strain r gave a ____ appearance but s gave a ___ appearance

A

rough; smooth

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

mice with _ strain were killed not just sick like with other strain

A

S

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

griffiths mixed r as a live strain and s as dead strain and the colonies that showed up were all s and killed mice

what should have happened?

A

idea was that colonies should have been rough and not lethal because s stain was dead; transformation was discovered in this way

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

avery, macleod, and mcCarty added an RNase (takes out RNA) and a protease (takes out protein) in the smooth strand and then mixed it with r, what happened?

A

transformation continued to happen; mice dead and smooth colonies

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

avery, macleod, and mcCarty added a DNase in the smooth strand and then mixed it with r, what happened?

A

no transformation; rough colonies and not lethal

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

avery, macleod, and mcCarty finally mixed r with just DNA from s and what happened?

A

smooth colonies; dead mice (DNA is the element of transformation)

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

DNA to RNA

A

transcription

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

RNA to protein

A

translation

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

bacteria does ____ replication, very rapid

A

bi-directional

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

the bi-directional replication of bacteria has 2 ___ ___ but ___ start of replication origin

A

2 replication forks; one

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

what structure shows up when microbe is halfway through replication

A

the theta structure

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

in termination links of chromosomes; that are resolved by topoisomerases (eukaryotes)

A

catenanes

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

in termination dimerization are resolved by ____ in prokaryotes

A

recombinases

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

plasmid replication is very different; not ___ ___

A

bi-directional

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

eukaryotic genes have introns which are _____ regions and exons which are ____ regions

A

non-coding; coding

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

the bacterial gene only has ____ regions

A

coding

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

what are the promotor sites in bacteria?; they are ___ ____ binding (found in promotor; highly conserved)

A

-10, -35; rna polymerase

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

things that are upstream are to the ___ of the gene (5’ - 3’)

A

left

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

_____ is down stream

A

terminator

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

-10 is 10 base pairs ____ from gene

A

upstream

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

what is the transcription start site

A

+1 (upstream)

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

the promotor regions (-10, -35) guide _____ process

A

transcription

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
the leader sequence is between what
transcription and translation start site
26
the ribosome binding site is the _____ start site
translation
27
the bacteria has its own specific 5 subunit core enzyme (alpha, alpha, beta, beta' and w) which is a?
rna polymerase
28
RNA polymerase binds with __ ___ in promotor region
sigma factor
29
sigma factor and core enzyme is called
holoenzyme
30
purpose is to help recognize promotor so core enzyme can attach
sigma factor (essential; once core enzyme binds, sigma can leave)
31
in Rho- dependent termination____ attaches to mRNA; influences polymerase and RNA to fall off in termination
Rho
32
factor independent termination has no ____
Rho
33
in factor independent termination there has to be ___ ___
inverted repeats
34
the inverted repeat is significant because it creates a ___ ____ structure (two inverted repeats will compliment)
stem loop
35
the factor independent termination also has __ rich region which are weak and that in combination with the loop will cause ____ to fall off
U rich; polymerase
36
transcription in eukaryote is complex; has splice sites and does alternate splicing to remove introns by _____
spliceosome
37
mature mRNA of eukaryotes has what two things
5' cap & poly-a tail
38
the leader sequence in bacterial region is an ___ ____
untranslated region
39
the translation start codon is
AUG
40
e. coli ribosome binding site is
shine-dalgarno site
41
translation stop codon for bacterial translation
UAA, UAG, UGA
42
genes ordered one after another with one promoter; genes involved in same pathway
operon (all controlled by same promoter and terminator)
43
prokaryotes can couple ___ and ___ because they dont have to use DNA from nucleus
transcription and translation
44
transcriptional regulation: most genes that are always expressed
constitutive
45
transcriptional regulation: activated by a protein; activator protein binds near promotor; turns ON gene OFF (control of a gene that is turned OFF)
positive control
46
three levels of control for prokaryotes
transc. , translation, post- translational
47
transcriptional regulation: uses repressor protein (turning OFF something that is ON)
negative control
48
____ are down stream products that come from gene being transcribed and translated and activate a protein to help activate transcription (helps to control an activator)
inducer
49
___ ___ typically focuses on up or down regulating an always somewhat on gene
transcriptional regulation
50
allow some transcription even under repression
leaky promotors
51
two component system regulates ____
transcription
52
a sensor kinase is in the ____ and responding to it in the _____ is the response regulator
membrane, cytoplasm
53
the two component system senses and responds to _____ _____ (up regulate or down regulate transc.)
changing environment
54
the sensor kinases can respond to changes in _____; then internal response regulator turns genes on or off
osmolarity
55
attenuation is apart of _____ regulation
transcriptional
56
tryptophan synthesis operon is unique because the leader sequence is ____; why?
translated; has 4 attenuator sequences that give rise to stem loop
57
2 trp codons side by side is a ____ ____ (now microbe needs two to continue)
limiting factor
58
in low tryptophan levels, the ____ will pause and give mRNA to form stem loop called antitermination loop.
ribosome
59
the antitermination loop allows _____ to continue to make more tryptophen
transcription
60
in high tryptophan: terminator loop forms and stops transcription, why?
doesn't need more trytophan
61
riboswitches are ____ regulation
transcription
62
riboswitches fold into ____ ___, a metabolite alters their folding structure
secondary structure
63
metabolites (down stream; come from gene) regulate transcription by interacting with ____ and changing its structure to turn transcription ___
riboswitch; off (riboflavin)
64
translation start site is upstream and called
RBS