Brainscape's Knowledge GenomeTM

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


See full index

Microbiology > mechanisms of microbial genetics > Flashcards

mechanisms of microbial genetics Flashcards

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

what are the functions of DNA

A

store genetic material
direct and regulate the construction of proteins necessary to a cell for growth

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

what is a gene

A

dna that is read or transcribed to produce an RNA molecule through transcription

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

what is translation

A

when mRNA provides information for the ribosome to catalyze protein synthesis

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

what is gene expression

A

the synthesis of a specific protein with a sequence of amino acids that is encoded in the gene

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

what are the stages of replication, transcription and translation

A

initiation
elongation (polymerization)
termination

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

What is central dogma

A

the flow of genetic information from DNA to RNA

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

what is the process from dna to a protien

A

DNA>transcription>RNA>translation

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

What is replication

A

the process of DNA being copied

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

what is the semiconservative replication model

A

when 2 strands of the double helix separate and each strand is the template for for a complementary strand

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

what did meselson and stahl use in their dna experiments

A

a heavy isotope of nitrogen (15N) that was incorporated into nitrogenous bases and then DNA and E. coli

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

what medium was the e coli cultured in for dna testing

A

one with 14N and allowed to grow for one generation

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

how is dna separated

A

using and ultracentrifuge where dna forms bands according to its desity

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

what was expected of dna after being ultracentrifugated

A

15n would form a band at higher density than those grown in 14N

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

what were the results of the first generation dna

A

the band was between 15n and 14n

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

what happened to cells grown as a second generation in 14n

A

one band was between 14n and 14 and the second band corresponded to th second band of DNA

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

how long does it take E. coli dna to replicate

A

42 minutes

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

what DNA polymerase is required for DNA synthesis

A

DNA pol 3

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

what are DNA pol 1 and DNA pol 2 used for

A

repair

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

what does DNA pol 3 do

A

adds deoxyribonucleotides to a nucleotide on the template strand

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

where does DNA get the energy for replication

A

the bonds of the 3 phosphate groups attached to each nucleotide, when the bond is broken diphosphate is released allowing phophpdiester to bond

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

what is DNA wrapped around

A

histones in eukaryotes and arches and histone like proteins in bacteria

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

what relaxes a supercoiled DNA molecule

A

topoisomerase 2

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

what is another name for topoisomerase 2

A

DNA gyrase

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

what does helicase do

A

separats dna strands by breaking the hydrogen bonds between base pairs.

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

what are replication forks

A

y shaped structures that are formed at the origin of replication allowing for bidirectional replication and a structure that looks like a bubble

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

what prevents single stranded DNA from rewinding into a double helix

A

the dna near the replication fork being coated with single stranded binding proteins

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

what direction is DNA pol 3 able to add nucleotides

A

only in the 5’ to 3’ directions

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

why can dna pol 3 only work in the 5’-3’ directions

A

because DNA polymerase requires a free 3’ -OH to add nucleotides too

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

can DNA pol 3 add a nucleotide if a 3’ is not available

A

no

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

Describe th primer

A

an RNA sequence that provides free 3’ ok end and is 5-10 nucleotides long and complementary to the parental or template dna

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

what is the primer synthesized from

A

RNA primase an RNA polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what makes RNA polymerase different from DNA polymerase

A

RNA polymerase does not need a free 3’ -oh group to synthesize an RNA molecule

33
Q

what is the leading strand

A

the continuously synthesized DNA strand. the 5’-3’ strand

34
Q

what are Okazaki fragments

A

fragments of DNA replicated on the 3’-5’ DNA strand (lagging strand)

35
Q

how many primers does the lagging strand need

A

one for each Okazaki fragment

36
Q

what is the sliding clamp

A

a protein that holds the DNA polymerase in place as it adds nucleotides to the lagging side

37
Q

how does topoisomerase prevent overwinding of DNA at the replication fork

A

it causes temporary nicks in the dna helix and the resealing it

38
Q

what happens to RNA primers during DNA replication

A

it is replaced by dna

39
Q

how are RNA primers removed

A

the exonuclease activity of DNA polymerase 1 removes it and the gaps are filled in

40
Q

what does DNA ligase do

A

fills the gaps seals the gaps between the dna that replaced RNA Primer and the previously synthesized dna

41
Q

how are the DNA chromosomes separated from eachother

A

bacterial topoisomerase 4

42
Q

what makes dna replication in bacteria from eukaryotes

A

DNA gyrase and topoisomerase 4

43
Q

DNA pol 1 function

A

exonuclease activity removes RNA primer and replaces it with newly synthesized DNA

44
Q

DNA pol 3 function

A

main enzyme that adds nucleotides in the 5’ to 3’ direction

45
Q

helicase function

A

opens the DNA helix by breaking hydrogen bonds between the nitrogen bases

46
Q

ligase function

A

seals the gaps between Okazaki fragments on the lagging strand to create one continuous dna strand

47
Q

primase function

A

synthesizes RNA primers needed to start replication

48
Q

single stranded binding proteins function

A

bind to single-stranded DNA to prevent hydrogen bonding between DNA stranded DNA

49
Q

sliding clamp function

A

helps hold DNA pol 3 in place when nucleotides are being added

50
Q

topoisomerase 2 (DNA gyrase) function

A

relazes supercoils chromosome to make DNA more accessible for the initiation of replication, helps relieve the tress on dna when unwinding, by causing breaks and the resealing dna

51
Q

topoisomerase 4 function

A

introduces single stranded break into concatenated chromosomes to release them from each other, and then reseals the dna

52
Q

how is dna replication in eukaryotes different than bacteria

A

it is slower, has multiple points of origin, uses RNase h instead of dna pol 1 for a primer removal, uses pol8 and pol e for strand elongation instead of dna pol 3

53
Q

what is ribonuclease h

A

the enzyme that removes RNA primer in eukarotes instead of dna polymerase in Bactria

54
Q

what are telomeres

A

the ends of linear chromosomes that consist of noncoding repetitive sequences

55
Q

what do telomeres do

A

protect coding sequences from being lost as cells continue to divide

56
Q

what does telomerase contain

A

a catalytic part and a built in RNA template

57
Q

where does telomerase attach

A

to the end of the chromosome and complementary bases to the RNA template on the 3’ end of the DNA strand

58
Q

What is rolling circle replication

A

another process of dna replication used by bacteria, plasmids, bacteriophages and some eukaryote viruses

59
Q

what happens in rolling circle replication

A

one strand of dna is nicked at the double stranded origin site

dna polymerase binds to the 3’ oh of the nicked trans and replicates unidirectionally

look it up more it doesn’t make sense

60
Q

what is transcription

A

when information encoded within the dna sequence of one or ore genes is transcribed into a strand of dna

61
Q

what is a transcription bubble

A

the partially unwound portion dna where rna synthesis is taking place

62
Q

what is the antisense strand

A

the strand of dna that is acting as a template

63
Q

what is the sense strand

A

the non template strand of dna that is almost identical to the rna

64
Q

what is a critical difference between dna polymerase and rna polymerase

A

dna polymerase requires a 3’ oh group requiring a primer where rna polymerase does not

65
Q

what does rna polymerase comprise in ecoli

A

6 polypeptide subunits, 5 that compose the polymerase core enzyme responsible for adding rna nucleotides and a sigma factor

66
Q

what does the sigma factor do

A

enables RNA polymerase to bind to a specific promoter for the trascription of genes

67
Q

where does the initiation of transcription begin

A

the promotor

68
Q

what is a promoter

A

a dna sequence onto which the transcription machinery binds and initiates transcription

69
Q

what nucleotide is transcribed as the initiation site for transcription

A

the first 5’ nucleotide in what’s being copied

70
Q

what is upstream?

A

the nucleotides preceding the initiation site

71
Q

what is down stream

A

the nucleotides following the initiation site

72
Q

when does elongation in transcription begin

A

when the sigma subunit dissociates from the polymerase allowing the core enzyme to synthesize rna complementary to dna

73
Q

how does polymerase differ between prokaryotes and eukaryotes

A

eukaryotes use polymers 1, 2, 3 that are different from bacterial rna polymerase

74
Q

what do polymers 1,2,3 transcribe

A

each a different subset of genes

75
Q

what type of rna polymerase do arches contain

A

just one more closely related rna polymerase 2 than bacterial rna polymerase

76
Q

what does monocistronic mean

A

eukaryotic mRNA that only encodes a single polypeptide

77
Q

what does polycistronic mean

A

prokaryotic mRNA that encode s multipolypeptide

78
Q
A

Microbiology (15 decks)

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