Brainscape's Knowledge GenomeTM

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


See full index

Micr 221 > Midterm 1 > Flashcards

Midterm 1 Flashcards

1
Q

Main difference between bacteria and archea

A

Bacteria have peptidoglycan in cell wall

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

Strain

A

Descendants of a single pure culture

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

Species

A

Group of strains with similar traits

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

What does a simple stain show

A

Size, shape, morphology

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

Hyperthermophiles

A

High temperature, branched saturated membrane

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

Psychrophiles

A

Low temperature, unsaturated membrane, fewer H bonds

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

Acidophiles

A

Low pH, pump H+ out of cell

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

Alkaliphiles

A

High pH, increase H+ in cell, produce acidic metabolites

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

Comensals

A

One benefits, other is unharmed

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

Differential media

A

Distinguish what bacteria possess certain traits by interaction with media

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

MacConkey Agar selects for…

A

Gram Negative Cells

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

MacConkey Agar differentiates….

A

Lac+ from Lac-

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

Binary Fission

A

Primary reproduction of bacteria

2 daughter cells from mother

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

Steps of binary fission

A
  1. DNA replication
  2. Elongation
  3. Septum forms via divisome
  4. Cells split
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

4 growth phases of bacteria

A
  1. Lag
  2. Log
  3. Stationary
  4. Death
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Lag phase

A

Nutrients/DNA being replicated, cells not splitting yet

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

Log phase

A

Cells rapidly split and number increases exponentially

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

Stationary phase

A

Nutrients are low so growth slows

Cell density high

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

Death phase

A

Cells degrade

Months to years

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

Counting chamber

A

Manually counts cells/mL from a plate

Live and Dead cells

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

Plate counting

A

Manually count colonies from a plate

CFU (collony forming unit)

Only shows viable cells

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

Limitations to plate counting

A

Colonies can blend together

1 colony can come from multiple cells

One cell can only make one colony

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

Serial dilutions

A

Make plate counting easier to count/more accurate

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

Cell mass methods

A
  1. Dry weight
  2. Turbidity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Dry weight mass

A

Will include live and dead cells

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

Turbidity

A

Uses spectroscopy
Based on absorbance/scattered light

Includes dead cells

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

Hypertonic solution

A

Water leaves cell

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

Hypotonic solution

A

Water enters cell

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

Compatible solutes

A

For hypertonic solutions

  • Prevents escape of water from cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How does a cell react to a hypotonic solution

A

Mechanosensitive channels

  1. Water enters cell
  2. Cytoplasm stretches
  3. Channels open
  4. Solutes leave cell

Osmotic pressure relieved

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

Damage caused by pH changes

A

Cytoplasmic membrane, protein activity

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

How is cytoplasm pH maintained

A

Importing or exporting protons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What group exports protons

A

Acidophiles

Inside pH is too low (acidic)
Therefore, make more basic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What group imports protons

A

Alkalphiles

Inside pH too high (basic) therefore, make more acidic

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

What do hyperthermophiles have that others don’t

A

Most ether lipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Levels of temperature bacterium

A

Psychrophiles
Psychrotrophs
Mesophiles
Thermophiles
Hyperthermophiles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What temperature does mesophiles like

A

Human body temperature
~37C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are most psychrophiles responsible for

A

Refrigerated food spoilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are most mesophiles responsible for

A

Human pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What role does oxygen have with bacteria

A

Essential for some, toxic to others

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

How does oxygen damage some bacteria

A

Forms Reactive Oxygen Species (ROS)

Oxidizes sensitive groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Reactive Oxygen Species do what

A

React with proteins lipids, nucleic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Remembering why oxygen can be toxic

A

H2O vs H2O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

How do bacterial enzymes help protect against ROSs

A

Break down molecule/change it

2H2O2 -> 2H2O + O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Obligate aerobes

A

Need oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Obligate anaerobes

A

Grow without oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What does oxygen kill

A

Obligate anaerobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What does oxygen do to facultative anaerobes

A

Beneficial, not essential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What does oxygen do to aerotolerant anaerobes

A

No impact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What levels of oxygen do microaerophiles need

A

Low Oxygen

Can’t survive atmospheric levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Testing Oxygen sensitivity

A

Top is oxic
Bottom is anoxic

Wherever cells end up in tube show ideal oxygen levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Autoclaving

A

High pressure steam
Sterilizes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Pasturization

A

Kills pathogens with moderate heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What does cold do to bacteria

A

slows metabolic activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What effect do hypertonic conditions have on microbial growth

A

Dehydration slows microbial growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What do extreme pH conditions do to microbial growth

A

Impacts protein function and slows growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What products have general targets

A

Disinfectants and antisepctics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Disinfectant

A

Used for objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Antiseptic

A

Used on live tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What have specific targets

A

Antibiotics

Targets are specific to bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Oligotrophic environment

A

Low nutrients
Bacteria activate stringent response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Response to oligotrophic environment

A

Slowed metabolism, increased protein production to protect cell/dna

Persister cells and endospores can form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Persister cells

A

Growth arrested bacterial cells

Resistant to antibiotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Endospores

A

Form inside a vegetative mother cell

Different structure, same genetics

Released via lysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Resistance of endospores

A

Highly resistant to UV, heat, desiccation

Protected against chemicals, antibiotics, phage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Advantage of endospores resistance

A

Better survival in poor conditions

Can reform vegetative cells in proper conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What does the core of an endospores contain

A

Nucleotide
Ribosomes
Etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What surrounds an endospore core

A

Cortex (peptidoglycan)
Coat (Protein)
Exosporium

Impermeable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Endospore formation

A
  1. Cell division
  2. Septum forms
  3. Forespore develops
  4. Forespore engulfed
  5. Cortex forms
  6. Coat forms
  7. Lysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Planktonic

A

Free floating (bacterium in lab)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Biofilm

A

Communities of bacterium forming a matrix (in nature)

72
Q

Formation of biofilms

A
  1. Quorum sensing
  2. Autoinducer secreted (proportion relative to amount of cells)
  3. High AI = pili made
  4. Extra cellular polymeric substance (EPS) made
73
Q

Planktonic to Biolfilm

A
  1. Adhesion to surface -> sessile
  2. Cell division
  3. Cells stick and make EPs
74
Q

Bacterial adhesion to host cells is

A

Specific via adhesions

75
Q

Bacterial adhesion to abiotic surfaces is

A

Non-specific via bacterial components

76
Q

What is the EPS

A

Slimy matrix, helps attach bacteria

Traps nutrients

Secreted or released via death

77
Q

What kind of gradient formed by biolfilms

A

Oxygen gradient

78
Q

Explain oxygen gradient of biolfilms

A

Surface = more oxygen = more nutrients = more metabolically active

79
Q

Innate immune response

A

Nonspecific but fast

80
Q

Adaptive immune response

A

Specific but slow

81
Q

Chemical mediators

A

Promote inflammation, opsonization, make pores in cell wall

82
Q

Opsonization

A

Help phagocytes recognize bacteria

83
Q

Opsonization process

A
  1. C3b binds surface
  2. Receptors on phagocyte recognize c3b
  3. Phagocytoses
84
Q

Dendritic cells

A

Degrade antigens, activate T and B cells

85
Q

Infection stages

A
  1. Adhesion
  2. Proliferation
  3. Invasion
  4. Tissue damage
86
Q

Active penetration

A

Virulence factors

87
Q

Passive penetration

A

Unrelated event (broken skin)

88
Q

How do pathogens avoid detection

A

Intracellular pathogens

89
Q

How do pathogens avoid recognition

A

Modify, decrease, hide antigens

90
Q

Endotoxin

A

Lipopolysachharide (LPS)

Released if cell is listed
Can lead to sepsis

91
Q

Exotoxins

A

Secreted
Ex. Neurotoxins

92
Q

Quinolones/fluoroquinolones

A

Target topoisomerase of bacterium

93
Q

narrow host range

A

Closely related species can replicate plasmid

94
Q

Broad host range

A

Plasmid can be replicated in many species

95
Q

How are plasmids classified

A

Accessory genes

96
Q

Resistance plasmids

A

Protect bacteria against antibiotics

97
Q

Virulence plasmids

A

Genes for virulence factors

98
Q
A
99
Q

Example of virulence plasmids

A

Enterotoxigenic E.Coli (ETEC)

100
Q

What does ETEC plasmid encode for

A

Pili and toxins

101
Q

Conjugation plasmids contain what

A

Sex pilis genes, MOB genes

102
Q

What do MOB genes do

A

Encode proteins

Deliver plasmid into pilus

103
Q

Mobilizable plasmids

A

MOB genes, no sex pilus genes, needs pilus from other cells

104
Q

Transposable elements

A

Nucleic acid that can be transferred between DNA molecules (transposition)

Within chromosome
Chromosome to plasmid

105
Q

Simple transposition uses what mechanisms

A

Cut and paste

106
Q

replication transposition uses what mechanisms

A

Copy and paste

107
Q

Transposable elements

A

Insertion sequence
Inverted repeat

108
Q

Insertion sequence does what

A

Encodes transposase
Has inverted repeats on either end

109
Q

What do inverted repeats do

A

Recognition sites for transposase

110
Q

What does transposase do

A

Cuts DNA at IRs for transposition and inserts

111
Q

What are direct repeats

A

Repaired dna flanking IRs after transposition

112
Q

Unit transposons have what

A

IRS
Transposase gene
Resolvase gene (or others)
Accessory genes

113
Q

Significance of transposons

A

Prevent inactivation of genes in new chromosome, transfer accessory genes

114
Q

What do conjugation genomic islands encode

A

Excision, conjugation, integration

115
Q

What do mobilizable genomic islands encode

A

Excision, integration

116
Q

Pathogenicity islands do what

A

Carry virulence factors

Turn a safe cell into a pathogen

116
Q

What must new DNA do to be retained

A

Integrate into genome
OR
Replicate apart from genome

117
Q

Example of conjugation

A

F factor

118
Q

Steps of Conjugation: F factor

A
  1. Donor cell expresses sex pilus
  2. Attaches sex pilus to recipient cell
  3. Protein changes in pilus convert it to a type 4 secretion system (T4SS) - retracts
  4. Relaxosome cuts at oriT site - replication
  5. MOB genes encode coupling factor - pulls dna to T4SS
  6. DNA enters recipient
  7. Replication
119
Q

What is transferred when making an Hfr cell

A

Bacterial chromosome and F factor

Recombines

120
Q

What is transferred from an Hfr cell

A

Bacterial chromosome and F factor

Makes F’

121
Q

Transformation requires what

A

COM proteins

122
Q

what can trigger competence

A

Cell signalling
Nutritional stress
DNA damaging agents

123
Q

Process of transformation

A
  1. Secrete competence-stimulating peptide (CSP)
  2. Threshold met = receptor activated
  3. Com genes transcribed
124
Q

Why is there a threshold for CSP

A

Makes sure there are other cells present for exchange

125
Q

Com proteins

A

Transformation pilus
Membrane receptor
Nuclease
Transport Complex

126
Q

Transformation pilus

A

Binds dsDNA

127
Q

Membrane receptor

A

Binds dsDNA at other end and attaches it to cell surface

128
Q

Nuclease

A

Cuts dsDNA to make ssDNA

129
Q

Transport complex

A

Sends ssDNA into cytoplasm

130
Q

What does RecA do - lac operon

A

Catalyzes recombination of ssDNA

131
Q

Artificial competence

A

Lab induced competent bacteria

132
Q

2 methods of artificial competence

A
  1. Chemical (calcium chloride and heat shock)
  2. Electroshock
133
Q

What is the name of a phage that mediates transfer

A

Transducing particle

134
Q

Lyric cycle - phage

A
  1. Absorbtion
  2. Injection
  3. Degradation of host dna
  4. Protein synthesis and packaging
  5. Lysis
135
Q

Generalized transduction

A

Randomly incorporating pieces of host dna into phage during lytic cycle instead of lytic dna

Forms transducing particle

136
Q

What can a generalized transducing particle do

A

Inject dna, no lytic cycle

137
Q

Lysogenic cycle - phage

A
  1. Absorbtion
  2. Injection
  3. Integration
  4. Replication of cells
  5. Trigger causes lytic cycle to begin
138
Q

Specialized transduction

A

Contains bacterial dna from beside excision site of phage dna

139
Q

Lysogenic conversion

A

Conversion of Lysogenic phenotype via prophage

140
Q

Prophage

A

phage dna

141
Q

Extracellular vesicles

A

Contains cargo
Gram negatives

142
Q

Steps of pathogensis

A
  1. Sense host environment
  2. Make needed proteins for attachment
  3. Evaded immune system
  4. Kill host cells
143
Q

Sigma factors

A

Guide RNAP to promoter

144
Q

Closed complex - transcription - occurs when

A

RNAP holoenzyme binds to promoter

145
Q

Open complex - transcription - occurs when

A

RNAP unwinds DNA

146
Q

2 types of terminators

A

Factor dependent (Rho)
Intrinsic (Hairpin)

147
Q

Constitutive genes

A

Essential genes, always needed

148
Q

Negative transcription control uses what

A

Repressors

149
Q

Riboswitch - transcription

A

Leader region - 2 conformations

Allows or prevents transcription to continue

Requires metabolite or ligand

149
Q

Process of a transcription riboswitch that is usually off

A

Metabolite forms anti terminator

Transcription continues

150
Q

Process of a transcription riboswitch that is usually on

A

Metabolite forms anti-antiterminator

Termination stops

151
Q

What is essential for bacterial replication

A

Ribosomes - translation

152
Q

What do many antibiotics target

A

Ribosomes

153
Q

Initiator tRNA

A

First tRNA needed

Charged with fMET in bacteria

Anticodon binds to start codon

154
Q

What is responsible for charging tRNA correctly

A

Aminoacyl-tRNA synthetases

155
Q

What bond binds amino acid with tRNA

A

Reactive ester bond

156
Q

What binds are formed between aminos in tRNAs

A

Peptide bonds

157
Q

Initiation of translation

A
  1. 16s bind to RBS
  2. Initiator binds to start codon in P site
  3. Initiation factors help if needed
  4. Forms 30s Complex
  5. 50s joins 30 S
158
Q

Elongation - translation

A
  1. EF-Tu delivers tRNA to A site
  2. Anticodon binds
  3. Peptide bond formed (PTC)
  4. Translocation (EF-G)
159
Q

Termination - Translation

A

Stop codon - release factors

160
Q

Tetracyclines

A

Bind to A site, block delivery

Bacteriostatic

161
Q

Bacteriostatic

A

Inhibits growth, does not kill

162
Q

Macrolides

A

Bind 50 S, block E site

163
Q

Lincosamides

A

Binds 50S A site

Blocks peptide bond formation

164
Q

2 conformations of riboswitch - translation

A

Sequester
Anti-sequester

165
Q

Sequestor

A

Blocks RBS

166
Q

Anti-sequestor

A

RBS available

167
Q

Cis-encoded sRNA

A

Matches template strand

168
Q

Trans-encoded sRNA

A

From other DNA

169
Q

How does sRNA impact translation

A

Binding RBS: block initiation
Binding gene: block elongation
Binding Leader: prevent sequestor
Binding mRNA: degrade mRNA

170
Q

RyhB sRNA

A

Fur: repressor
Fe2+: co-repressor

171
Q

Limited Fe2+: what happens

A

RyhB binds mRNA of non essential proteins -> degradation -> more iron for needed protein

172
Q

High Fe2+: what happens

A

Fe2+ binds to Fur, does not translate ryhB, no mRNA degraded

173
Q
A
174
Q

Proteolysis

A

Enzyme, transcription/translational factors

Cleave one part of synthesis, limits production of protein

175
Q

Multilevel regulation example

A

RpoE: sigma factor
Binds to RNAP
Controls damage repair genes

RseA: anti-sigma factor

Prevents RpoE from binding RNAP

Regulates when damage repair genes are coded

Micr 221 (3 decks)

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