Micro Exam 2 Answers Flashcards Preview

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Flashcards in Micro Exam 2 Answers Deck (96)
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1
Q

Is rigid with more beta sheets

A

thermophile

2
Q

What is the major difference between facultative organisms and aerotolerant anaerobes

A

facultative organisms grow better w/ oxygen

3
Q

Has a flexible alpha helix & fewer bonds

A

Psychrophile

4
Q

Cross-Linking
Penicillin binding, lose catalytic activity.
Transpeptidation

A

FtsL

5
Q

Responsible for rod or bacillus shape of cells

A

MreB

6
Q

of Generations=

A

duration of expo/generation time

7
Q

unsaturated fatty acids

A

psychrophile

8
Q

Can grow in 95oC

A

hyperthermophiles Archaea domain ONLY

9
Q

Separation of daughter strands during cell division

A

FtsK protein

10
Q

Anchors Z ring to cyto membrane
ATPase

A

FtsA

11
Q

Grows at 15oC

A

psychrophile

12
Q

has shorter fatty acid chains

A

psychrophile

13
Q

Grow at 45oC

A

thermophile

14
Q

Forms a Z ring that divides bacterial cells in half

A

Fts Proteins

15
Q

the higher the pH

A

the fewer the H+ ions (more OH) 10times

16
Q

breaks down H2O2 to oxygen + water

A

catalase

17
Q

used to grow a continuous culture in the laboratory

A

chemostat

18
Q

Measures cell concentration by turbidity

A

spectrophotometer

19
Q

what type of microscope can measure cell counts

A

phase contrast microscopy

20
Q

determines cell midpoint during Z ring formation

A

MIN proteins, middle is most free space

21
Q

grow best at slightely reduced oxygen levels (3-5% CO2)

A

Microaerophile

22
Q

Ten fold Seriel dilution factor

A

add 10 x each time

23
Q

cfu/ml=

A

dilution factor x mL

24
Q

of cells =

A

plate count x Dilution Factor/ mL dilution plated

25
Q

The primase side of template strand

A

3’ lagging strand

26
Q
A
  1. RNA primer
  2. Lagging Strand
  3. Primase
  4. Single Stranded Binding Protein
  5. Helicase
  6. DNA pol III
  7. Leading Strand
  8. 5’
27
Q

Unwinds double helix at replication fork

A

helicase

28
Q

lays down RNA at the start of DNA replication

A

Primase

29
Q

Seals Okzaki fragments together

A

ligase

30
Q

Creates Negative Supercoils in DNA

A

gyrase

31
Q

Which direction does sigma recognize promoter sequences

A

5’ to 3’

32
Q

The portion of NDA where replication starts is called

A

origin

33
Q

Each daugher cell receives a strand of DNA from the parent and newly synthesized complementary strand, what type?

A

Semi conservative

34
Q

Proofreading of Replication is performed by

A
  • 3’ to 5’ exonuclease activity of DNA polymerase
  • both Pol I & Pol III can do this
35
Q

Enzyme respobsible for removing RNA primer and replacing with DNA

A

DNA pol I

36
Q

Sythesizes leading strand 5’ to 3’

A

DNA Pol III

37
Q

What direction does RNA polymerase transcribe

A

3’ to 5’

38
Q

Specific DNA sequences that bind RNA polymerase

A

Promoters

39
Q

All the DNA sequences are recognized by

A

sigma factor

40
Q
A
  1. RNA Polymerase Core Enzyme
  2. Transcription downstream
  3. Sigma
  4. mRNA start
    • 35 sequence
  5. Pribnow Box
41
Q

How do you find an inverted repeat

A
  • One is on the leading strand
  • diagonal on the lagging strand & backwards
42
Q

Which strand do you transcribe?

A

lagginst strand

43
Q

How do you form a stem loop

A
  • left side read from left to right
  • middle= loop
  • right side= right to left, run of uuuus
44
Q

Signal for the initiation of transcription

A
  • Sigma Factor Recognition of a promoter
45
Q

What causes the termination of transcription?

A

stem loop structure, followed by run of UUUs

46
Q

Initiation of protein sythesis begins with

A

30S ribosomal subunit.

47
Q

What is the start codon that always initiates translation

A

AUG

48
Q

What does shine dalgarno do?

A

direct ribosome to proper start site

49
Q

The site where the growing polypeptide chain is held

A

P site

50
Q

The acceptor site, charged tRNA attaches

A

A site

51
Q

release factors will bind at termination

A

A-site

52
Q

Subunit that first bind to mRNA during translation initiation

A

Small 30 S

53
Q
A
  1. A- site
  2. Large 50S Subunit
  3. Small 30 S Subunit
  4. E-site
  5. P-Site
54
Q

What does a prokaryotic mRNA require to initiate protein sythesis?

A

Shine Dalgarno sequence and AUG codon

55
Q

required for termination of protein sythesis in prokaryotes

A

Stop Codon

56
Q

23S is

A

catalyst for peptide bond formation during protein synthesis

57
Q

A single amino acid may have multiple codons is called

A

degeneracy

58
Q

How many hydrogen bonds does cytosine and guanine have

A

3

59
Q

Aminoacyl-tRNA sythetase is responsible for…

A

attachment of amino acid to proper tRNA molecule

60
Q

Ribosome that holds tRNA to growing polypeptide chain is

A

P site

61
Q

What do TAT proteins do?

A

export folded proteins

62
Q

What does signal recognition particle do

A

export unfolded proteins to be inserted into c.membrane

63
Q

How many hydrogen bonds does adenine tyrosine and uracil have?

A

2

64
Q

Reading the codon chart, what do you need to find in the code for start codon?

A

AUG

65
Q

What is the codon for the ANTICODON of 5’ GCA 3’

A

CGU—> UGC (read backwards)

66
Q

Where a repressor bind in DNA

A

Operator

67
Q

Regulatory proteins that bind DNA are

A

homodimers containing helices

68
Q

Positive transcriptional regulation

A
  • Lactose induction (not catabolite)
  • where the regulator is located
69
Q

A regulatory system monitoring/ responding to cell density

A
  • quorum sensing, can count, upstream
  • before gene product is made
70
Q

Regulation that responds to external environment

A

signal transduction

71
Q

When lactose is present what occurs?

A

lactose inducer binds the latose repressor

72
Q

In positive regulation activator proteins stimulate transcriptional activity by

A
  • making a promoter more easily recognized
  • bound by sigma factor
73
Q

Inducer

A
  • repressor cannot bind
  • an effector
74
Q

Corepressor

A

an effector, repressor binds

75
Q

Organisms will use glucose before any other sugars

A

catabolite repression

76
Q

How many hydrogen bonds does cyto

A
77
Q
A
  1. Ribose
  2. Deoxyribose (h only)
78
Q
A
  1. Where amino acid attaches
  2. 3’ End
  3. 5’ End
  4. Anticodon
79
Q
A
  • A) Lagging phase
  • B) Exponential
  • C)Stationary
  • D) Death
80
Q

Why bacteria is measured in cfu/ml

A

because replicate forming a cluster. Hard to measure individual bacteria

81
Q

Antiparallel

A

parallel but opposite directions. 5’ to 3’ and 3’ to 5’.

82
Q

Positive supercoiling

A

overwinding, tightening

83
Q

Negative Supercoiling

A

unwinding, twists in the opposite direction

84
Q

Why is primase important for DNA synthesis

A
  • cannot initiate synthesis witout primer
  • needs a double stranded region to attach, rna does not have this
  • rna primer
85
Q

The first amino acid added to a growing polypeptide chain

A

f-met

86
Q

in mRNA which end is translated first

A

5’

87
Q

5’ end terminated with a ( ) group

A

phosphate

88
Q

3’ end terminates with a ( ) group

A

OH

89
Q

What regulates tryptophan operon?

A

leader and attentuator regions

90
Q

when tryptophan is plentiful?

A
  • transcription and translation are almost simultaneous
  • ribosome is close behing rna polymerase
91
Q

When tryptophan is low

A
  • termination signal does not occur and transcription continues.
  • ribosome stalls to allow RNA pol to move ahead
92
Q

What distinguishes a strong promoter from a weak promoter?

A
  • will have a better match to the -10 and -35 consensus sequences
93
Q

A regulon

A
  • manages many different operons
  • operons is multiple genes transcribed together
94
Q

why cell myst synthesize lagging strand in small fragments

A

because it is going in opposite direction of helicase

95
Q

What does TAT stand for?

A

Twine Arginine Translocase

96
Q

Five things present in leader sequence for attenuation

A
  1. stop codon
  2. encodes 2 TRP amino acids
  3. ribosome stall at 2 & 3
  4. run of UUUUUs
  5. transcription stalls