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5 Evolutionary History of Biological Diversity > 27 Bacteria and Archaea > Flashcards

Flashcards in 27 Bacteria and Archaea Deck (221):
1

What is a genus of microorganism that can tolerate wide salt ranges?

Halobacterium, which is actually a archaea

2

What is Halobacterium?

An archaea genus that can tolerate high levels of salt.

3

What is the basic premise of the the Gram stain?

It dies peptidoglycan as purple so that bacteria that have it on their plasma membrane can be distinguished from those who do not have it on their plasma membrane

4

How can bacteria be classed based on how they appear under a Gram stain?

‘Gram-positive bacteria’ and ‘Gram-negative bacteria'

5

What is the structure of gram-postive bacteria?

The differences lie in the plasma membrane. In Gram positive bacteria the plasma membrane is covered with an external layer of peptidoglycan, which acts a the cell wall.

6

What is peptidoglycan?

A polymer composed of sugars cross-linked with polypeptides

It is the primary component of bacterial cell walls.

7

What is the structure of a gram-negative bacteria?

They have a phospholipid membrane bilayer that acts as the plasma membrane.

External to this is a comparatively thin layer of peptidoglycan.

External to this is an outer membrane, which consists of a phospholipid membrane bilayer.

Note that the peptidoglycan layer and the external phospholipid membrane bilayer are collectively called the 'cell wall.'

8

Generally speaking, are Gram-negative or Gram-positive bacteria more resistant to antibiotics? Why

Generally Gram-negative bacteria as many antibiotics work by inhibiting the peptidoglycan cross linking (this allows them to not affect human cells, which lack peptidoglycan)

9

What is the cell wall of a bacterium covered with?

Either a ‘slime layer’ or a ‘capsule'

10

What is a ’slime layer’?

An outer coating of a bacterium that is not dense or defined like a capsule

11

What is a ‘capsule’?

An outer coating of a bacterium that is very dense and defined, unlike a ’slime layer'

12

What can the slime coats/capsules of bacteria be covered with?

Fimbriae or pili

13

What is a pilus?

The singular form of pili

14

What are fimbriae?

Hairlike appendages that are shorter and more numerous than ‘pili'

15

What are ‘pili’?

Appendages that pull to cells together prior to horizontal gene transfer between bacteria.

They are longer but less numerous than fimbriae.

16

What is a taxis?

A directed movement toward or away from a stimulus.

17

What is a directed movement towards or away from a stimulus called?

A taxis

18

What is a positive taxis?

When the bacterium etc. moves towards a stimulus i.e. positive phototaxis towards light

19

What is the structure of a prokaryotic flagellum?

Embedded in the inner plasma membrane is a ‘motor’ which appears as a set of discs

In the centre of these disks is a ‘rod’ which extends outside the cell wall.

Just outside the cell wall the rod bends to form the ‘hook’. The ‘filament’ is the long trailing tail that extends form the hook

20

What is exaption?

When evolution repurposes features for other uses.

21

Where is the DNA of a bacterium located?

In a ’nucleoid'

22

What is a ’nucleoid’?

A region in a bacterium’s cytosol which holds the chromosome.

Note that it is not membrane bound and is thus loosely defined.

It appears lighter than surrounding areas in an electron microscope

23

What is a common way that bacteria tolerate changing environmental conditions i.e. periodic drought?

When they lack certain nutrients or during harsh conditions they can become dormant ‘endospores'

24

What are ‘endospores’?

A dormant form that many bacteria can assume when they lack certain nutrients or under harsh conditions.

The original cell produces a copy of its chromosome and surrounds it with a tough multilayered structure, forming the endospore.

Water is removed from the endospore, and its metabolism halts. The original cell then lyses, releasing the endospore.

When dehydrated they become active bacteria

25

Does meiosis occur in prokaryotes?

Nope

26

What are What is the ploidy of prokaryotes?

They are all haploid

27

What is 'genetic recombination’?

The combination of DNA from two sources

28

How does ‘genetic recombination’ occur in eukaryotes?

With fertilisation and in meiosis (crossing over)

29

What is the combination of DNA form two sources called?

Genetic recombination

30

How does genetic recombination occur in prokaryotes?

Since they do not perform meiosis or fertilisation it only occurs in ‘horizontal gene transfer'

31

What are the basic methods of horizontal gene transfer?

Transformation, transduction, conjugation and plasmids

32

What is ’transformation’ as a method of horizontal gene transfer?

The genotype and possibly phenotype of a prokaryotic cell are altered by the uptake of foreign DNA from its surroundings.

For example transformation occurs when a nonpathogenic cell takes up a piece of DNA carrying the allele for pathogenicity and replaces its own allele with the foreign allele, an exchange of homologous DNA segments. The cell is now a recombinant.

33

What is ’transduction’ as a method of horizontal gene transfer?

Phages (bacteriophages = viruses that infect bacteria) carry prokaryotic genes from one host cell to another.

If some of this DNA is then incorporated into the recipient cell’s chromosome by DNA recombination, a recombinant cell is formed.

34

What is ’conjugation’ as a method of horizontal gene transfer?

DNA is transferred between two prokaryotic cells (usually of the same species) that are temporarily joined.

In bacteria, the DNA transfer is always one-way: One cell donates the DNA, and the other receives it.

The tow bacteria are held together by a pilus

35

What are ’plasmids’ as a method of horizontal gene transfer?

Plasmids are small sections of DNA. They can be transferred between bacteria in ‘horizontal gene transfer'

36

In what form of horizontal gene transfer are pili (singular: plies) involved?

Conjugation

37

How are certain forms of horizontal gene transfer regulated?

With the ‘F factor'

38

What are the forms of F factor?

It is just F factor if it exists in the bacterial chromosome.

If it is in its own plasmid it is the ‘F plasmid'

39

What forms of horizontal gene transfer does the F factor regulate?

Conjugation and Plasmid

40

How does the F factor regulate conjugation?

The F factor consist of genes needed for the formation of a pilus etc.

Cells that have the F factor are called HFR (high frequency recombinant) During conjugation they act as donors and transfer genetic information to the other bacterium.

Note that the HFR bacterium can transfer the F factor to the host F- bacterium, causing it to become F+ (HFR)

41

What does the ‘F’ in F factor stand for?

Fertility

42

What is a ‘F+’cell?

One with the F factor

43

What is a ‘F-‘ cell?

One without the F factor

44

What does ‘HFR’ refer to?

High frequency recombination.

It refers to a bacteria which has the F factor in its chromosome and thus is F+

45

How does can the F plasmid be transferred to another bacterium?

A cell carrying an F plasmid (an F+ cell) forms a mating bridge with an F– cell. One strand of the plasmid’s DNA breaks at one point.

Using the unbroken strand as a template, the cell synthesizes a new strand . Meanwhile, the broken strand peels off, and one end enters the F– cell. There synthesis of its complementary strand begins.

DNA replication continues in both donor and recipient cells, as the transferred plasmid strand moves farther into the recipient cell.

Once DNA transfer and synthesis are completed, the plasmid in the recipi- ent cell circularizes. Now both cells are F+ cells.

46

What are ‘resistance genes’?

Genes that confer resistance to an antibiotic

47

What are genes that confer resistance to an antibiotic called?

‘Resistance genes'

48

What are resistance genes in the form of plasmids called?

R plasmids

49

What are ‘R plasmids’?

Plasmids that carry ‘resistance genes’ i.e. antibacterial resistance

50

What are plasmids that carry resistance genes called?

R plasmids

51

How can organisms be grouped based on their type of respiration? (think deeper than aerobic/anaerobic)

Obligate aerobes, obligate anaerobes and facultative anaerobes

52

What are ‘obligate aerobes’?

Organisms that must use O2 for respiration and thus can not survive with out it

They can only perform aerobic respiration

53

What are ‘obligate aerobes’?

Organisms that can only perform anaerobic respiration.

They are often poisoned by O2 due to its reducing nature.

54

What are some typical electron acceptors used in anaerobic respiration?

Nitrates (NO3-) and Sulfate (SO4 2-)

55

What are ‘facultative anaerobes’?

Organisms that use oxygen for aerobic respiration when possible.

However they are also able to perform anaerobic respiration or fermentation when necessary in anaerobic conditions

56

What are organisms that only perform aerobic respiration called?

Obligate aerobes

57

What are organisms that only perform anaerobic respiration called?

Obligate anaerobes

58

What are organisms that can perform aerobic or anaerobic respiration called?

Facultative anaerobes

59

Which cells are notoriously facultative anaerobes in the human body?

Muscle cells

60

Based on the from of respiration they perform, how can muscle cells be classed?

Facultative anaerobes (they prefer to do aerobic, but can do anaerobic respiration if oxygen deprived)

61

What is it called when atmospheric nitrogen is converted into compounds?

Nitrogen fixation

62

What is nitrogen fixation?

When atmospheric nitrogen is converted into compounds i.e NH3

63

How can organisms be grouped based on nutritional modes?

Photoautotroph, chemoautotroph, photoheterotroph, chemoheterotroph

64

What are photoautrophs in terms of energy source and carbon source?

Energy Source: Light
Carbon Source: CO2, HCO3- etc.

65

What are chemoautotrophs in terms of energy source and carbon source?

Energy Source: Inorganic chemicals such as H2S, NH3 or Fe2+
Carbon Source:CO2, HCO3- etc.

66

What are photoheterotrophs in terms of energy source and carbon source?

Energy Source: Light
Carbon Source: Organic compounds

67

What are chemoheterotrophs in terms of energy source and carbon source?

Energy Source: Organic compounds i.e glucose
Carbon Source: Organic compounds

68

What are are some examples of photoautotrophs?

Photosynthetic prokaryotes (for example, cyanobacteria);
plants; certain protists (for example, algae)

69

What are are some examples of chemoautotrophs?

Unique to certain prokaryotes (for example, Sulfolobus)

70

What are are some examples of photoheterotrophs?

Unique to certain aquatic and salt-loving prokaryotes (for example, Rhodobacter,
Chloroflexus)

71

What are are some examples of chemoheterotrophs?

Many prokaryotes (for example Clostridium) and protists; fungi; animals; some plants.

72

How do cyanobacteria perform nitrogen fixation?

Most cells in a filament carry out only photosynthesis, while a few specialized cells called heterocysts (sometimes called heterocytes) carry out only nitrogen fixation. Each heterocyst is surrounded by a thickened cell wall that restricts entry of O2 produced by neighboring photosynthetic cells. Intercellular connections allow heterocysts to transport fixed nitrogen to neighboring cells and to receive carbohydrates.

This is important as the O2 produced in photosynthesis inhibits the enzymes used for nitrogen fixation

73

What are the basic places 'metabolic cooperation’ is seen?

Nitrogen fixation in cyanobacteria and in biofilms

74

What is ‘metabolic cooperation'

Cooperation between prokaryotic cells allows them to use environmental resources they could not use as individual cells.

75

What are heterocysts?

Specialised cyanobacteria that are specialised to perform nitrogen fixation.

Note that they are the same species as the other cyanobacteria they metabolically cooperate with.

76

What are biofilms?

Sheets of bacteria that metabolically cooperate.

77

What are archaea?

They are one of the three basic domains but and are most similar to bacteria.

78

What are the basic ways that archaea, bacteria and eukarya can be compared?

Structure, Chemical composition, genetics and tolerance

79

How do bacteria, archaea and eukarya compare in terms of structure?

Bacteria, Archaea, Eukarya

Nuclear envelope: absent, absent, present
Membrane-bound organelles: absent, absent, present

Circular chromosome: present, present, absent

80

How do bacteria, archaea and eukarya compare in terms of chemical composition?

Bacteria, Archaea, Eukarya

Peptidoglycan in cell wall: present, absent, absent
Membrane lipids: unbranched hydrocarbons, soem branched hydrocarbons, unbranched hydrocarbons
RNA polymerase: one kind, several kinds, several kinds.

81

How do bacteria, archaea and eukarya compare in terms of genetics?

Bacteria, Archaea, Eukarya


Initiator amino acid for protein synthesis: Formyl-methionine, methionine, methionine
Introns in genes: very rate, present in some, common
Histones associated with DNA: Absent, present in some species, present

82

How do bacteria, archaea and eukarya compare in terms of tolerance?

Bacteria, Archaea, Eukarya

Response to the antibiotics streptomycine and chloramphenicol: Growth inhibited, no effect, no effect

Growth at temperatures >100ºC: No, some species, no

83

What class of organism are all extremophiles?

Archaea

84

What are extremophiles?

Organisms (all archaea) that live in extreme environmental conditions

85

What are organisms that live in extreme environmental conditions called?

Extremophiles

86

What are the basic types of extremophiles?

Extreme halophiles and extreme thermophiles

87

What are extreme halophiles?

Those that live is extremely salty environments

88

What is the salinity of sea water?

3.5%

89

What are organism that live in very salty environments called?

Extreme halophiles

90

What are archae that release methane called?

Mathanogens

91

What are methanogens?

Archaea that release methane

92

What is a unique byproduct of respiration in some archaea?

Methane is produced by methanogens

93

What are the major groups of bacteria?

Proteobacteria, chlamydia, spirochetes, cyanobacteria and gram-positive bacteria

94

What are proteobacteria divided into?

Alpha proteobacteria, Beta proteobacteria, Gamma proteobacteria, Delta proteobacteria and Epsilon proteobacteria.

(all are subgroups)

95

Describe proteobacteria.

Gram-negative bacteria that photoautotrophs, chemoautotrophs, and heterotrophs. Some proteobacteria are anaerobic, while others are aerobic.

96

What bacteria are gram-negative?

All groups except the ‘Gram-positive group'

97

What are alpha proteobacteria?

Many are associated with eukaryotic hosts

For example Rhizobium (“root-nodule”) bacteria and Agrobacterium are alphas.

Mitochondria evolved from aerobic alpha proteobacteria through endosymbiosis.

98

What class of bacteria are Rhizobacteria?

Alpha proteobacteria

99

What class of bacteria is Agrobacterium?

Alpha proteobacteria

100

What class of bacteria is mitochondria derived from?

Alpha proteobacteria

101

What are beta proteobacteria?

A nutritionally diverse subgroup that includes Nitrosomonas, a genus of soil bacteria that play an important role in nitrogen recycling by oxidizing ammonium (NH4+), producing nitrite (NO2–) as a waste product.

102

What are gamma proteobacteria?

A sub-group that includes some some bacteria.

Many other members are pathogenic such as ’Salmonella’, ‘Legionella’ (cause Legionnaire’s disease ), Vibrio cholerae (cholera) and E. coli

103

What causes Legionaire’s disease?

Legionalla bacteria

104

What causes cholera?

Vibrio cholerae (a type of bacteria)

105

What does ‘Legionella’ bacteria cause?

Legionaire’s disease

106

What does ‘vibrio cholerae’ cause?

Cholera

107

What type of bacteria is Legionella?

Gamma proteobacteria

108

What type of bacteria is E. coli?

Gamma proteobacteria

109

What type of bacteria is salmonella?

Gamma proteobacteria

110

What type of bacteria is vibrio cholerae?

Gamma proteobacteria

111

What is a directed movement towards or away from a stimulus called?

A taxis

112

What is a positive taxis?

When the bacterium etc. moves towards a stimulus i.e. positive phototaxis towards light

113

What is the structure of a prokaryotic flagellum?

Embedded in the inner plasma membrane is a ‘motor’ which appears as a set of discs

In the centre of these disks is a ‘rod’ which extends outside the cell wall.

Just outside the cell wall the rod bends to form the ‘hook’. The ‘filament’ is the long trailing tail that extends form the hook

114

What is exaction?

When evolution repurposes features for other uses.

115

Where is the DNA of a bacterium located?

In a ’nucleoid'

116

What is a ’nucleoid’?

A region in a bacterium’s cytosol which holds the chromosome.

Note that it is not membrane bound and is thus loosely defined.

It appears lighter than surrounding areas in an electron microscope

117

What is a common way that bacteria tolerate changing environmental conditions i.e. periodic drought?

When they lack certain nutrients or during harsh conditions they can become dormant ‘endospores'

118

What are ‘endospores’?

A dormant form that many bacteria can assume when they lack certain nutrients or under harsh conditions.

The original cell produces a copy of its chromosome and surrounds it with a tough multilayered structure, forming the endospore.

Water is removed from the endospore, and its metabolism halts. The original cell then lyses, releasing the endospore.

When dehydrated they become active bacteria

119

Does meiosis occur in prokaryotes?

Nope

120

What is the ploidy of prokaryotes?

They are all haploid

121

What is 'genetic recombination’?

The combination of DNA from two sources

122

How does ‘genetic recombination’ occur in eukaryotes?

With fertilisation and in meiosis (crossing over)

123

What is the combination of DNA form two sources called?

Genetic recombination

124

How does genetic recombination occur in prokaryotes?

Since they do not perform meiosis or fertilisation it only occurs in ‘horizontal gene transfer'

125

What are the basic methods of horizontal gene transfer?

Transformation, transduction, conjugation and plasmids

126

What is ’transformation’ as a method of horizontal gene transfer?

The genotype and possibly phenotype of a prokaryotic cell are altered by the uptake of foreign DNA from its surroundings.

For example transformation occurs when a nonpathogenic cell takes up a piece of DNA carrying the allele for pathogenicity and replaces its own allele with the foreign allele, an exchange of homologous DNA segments. The cell is now a recombinant.

127

What is ’transduction’ as a method of horizontal gene transfer?

Phages (bacteriophages = viruses that infect bacteria) carry prokaryotic genes from one host cell to another.

If some of this DNA is then incorporated into the recipient cell’s chromosome by DNA recombination, a recombinant cell is formed.

128

What is ’conjugation’ as a method of horizontal gene transfer?

DNA is transferred between two prokaryotic cells (usually of the same species) that are temporarily joined.

In bacteria, the DNA transfer is always one-way: One cell donates the DNA, and the other receives it.

The tow bacteria are held together by a pilus

129

What are ’plasmids’ as a method of horizontal gene transfer?

Plasmids are small sections of DNA. They can be transferred between bacteria in ‘horizontal gene transfer'

130

In what form of horizontal gene transfer are pili (singular: plies) involved?

Conjugation

131

How are certain forms of horizontal gene transfer regulated?

With the ‘F factor'

132

What are the forms of F factor?

It is just F factor if it exists in the bacterial chromosome.

If it is in its own plasmid it is the ‘F plasmid'

133

What forms of horizontal gene transfer does the F factor regulate?

Conjugation and Plasmid

134

How does the F factor regulate conjugation?

The F factor consist of genes needed for the formation of a pilus etc.

Cells that have the F factor are called HFR (high frequency recombinant) During conjugation they act as donors and transfer genetic information to the other bacterium.

Note that the HFR bacterium can transfer the F factor to the host F- bacterium, causing it to become F+ (HFR)

135

What does the ‘F’ in F factor stand for?

Fertility

136

What is a ‘F+’cell?

One with the F factor

137

What is a ‘F-‘ cell?

One without the F factor

138

What does ‘HFR’ refer to?

High frequency recombination.

It refers to a bacteria which has the F factor in its chromosome and thus is F+

139

How does can the F plasmid be transferred to another bacterium?

A cell carrying an F plasmid (an F+ cell) forms a mating bridge with an F– cell. One strand of the plasmid’s DNA breaks at one point.

Using the unbroken strand as a template, the cell synthesizes a new strand . Meanwhile, the broken strand peels off, and one end enters the F– cell. There synthesis of its complementary strand begins.

DNA replication continues in both donor and recipient cells, as the transferred plasmid strand moves farther into the recipient cell.

Once DNA transfer and synthesis are completed, the plasmid in the recipi- ent cell circularizes. Now both cells are F+ cells.

140

What are ‘resistance genes’?

Genes that confer resistance to an antibiotic

141

What are genes that confer resistance to an antibiotic called?

‘Resistance genes'

142

What are resistance genes in the form of plasmids called?

R plasmids

143

What are ‘R plasmids’?

Plasmids that carry ‘resistance genes’ i.e. antibacterial resistance

144

What are plasmids that carry resistance genes called?

R plasmids

145

How can organisms be grouped based on their type of respiration? (think deeper than aerobic/anaerobic)

Obligate aerobes, obligate anaerobes and facultative anaerobes

146

What are ‘obligate aerobes’?

Organisms that must use O2 for respiration and thus can not survive with out it

They can only perform aerobic respiration

147

What are ‘obligate aerobes’?

Organisms that can only perform anaerobic respiration.

They are often poisoned by O2 due to its reducing nature.

148

What are some typical electron acceptors used in anaerobic respiration?

Nitrates (NO3-) and Sulfate (SO4 2-)

149

What are ‘facultative anaerobes’?

Organisms that use oxygen for aerobic respiration when possible.

However they are also able to perform anaerobic respiration or fermentation when necessary in anaerobic conditions

150

What are organisms that only perform aerobic respiration called?

Obligate aerobes

151

What are organisms that only perform anaerobic respiration called?

Obligate anaerobes

152

What are organisms that can perform aerobic or anaerobic respiration called?

Facultative anaerobes

153

Which cells are notoriously facultative anaerobes in the human body?

Muscle cells

154

Based on the from of respiration they perform, how can muscle cells be classed?

Facultative anaerobes (they prefer to do aerobic, but can do anaerobic respiration if oxygen deprived)

155

What is it called when atmospheric nitrogen is converted into compounds?

Nitrogen fixation

156

What is nitrogen fixation?

When atmospheric nitrogen is converted into compounds i.e NH3

157

How can organisms be grouped based on nutritional modes?

Photoautotroph, chemoautotroph, photoheterotroph, chemoheterotroph

158

What are photoautrophs in terms of energy source and carbon source?

Energy Source: Light
Carbon Source: CO2, HCO3- etc.

159

What are chemoautotrophs in terms of energy source and carbon source?

Energy Source: Inorganic chemicals such as H2S, NH3 or Fe2+
Carbon Source:CO2, HCO3- etc.

160

What are photoheterotrophs in terms of energy source and carbon source?

Energy Source: Light
Carbon Source: Organic compounds

161

What are chemoheterotrophs in terms of energy source and carbon source?

Energy Source: Organic compounds i.e glucose
Carbon Source: Organic compounds

162

What are are some examples of photoautotrophs?

Photosynthetic prokaryotes (for example, cyanobacteria);
plants; certain protists (for example, algae)

163

What are are some examples of chemoautotrophs?

Unique to certain prokaryotes (for example, Sulfolobus)

164

What are are some examples of photoheterotrophs?

Unique to certain aquatic and salt-loving prokaryotes (for example, Rhodobacter,
Chloroflexus)

165

What are are some examples of chemoheterotrophs?

Many prokaryotes (for example Clostridium) and protists; fungi; animals; some plants.

166

How do cyanobacteria perform nitrogen fixation?

Most cells in a filament carry out only photosynthesis, while a few specialized cells called heterocysts (sometimes called heterocytes) carry out only nitrogen fixation. Each heterocyst is surrounded by a thickened cell wall that restricts entry of O2 produced by neighboring photosynthetic cells. Intercellular connections allow heterocysts to transport fixed nitrogen to neighboring cells and to receive carbohydrates.

This is important as the O2 produced in photosynthesis inhibits the enzymes used for nitrogen fixation

167

What are the basic places 'metabolic cooperation’ is seen?

Nitrogen fixation in cyanobacteria and in biofilms

168

What is ‘metabolic cooperation'

Cooperation between prokaryotic cells allows them to use environmental resources they could not use as individual cells.

169

What are heterocysts?

Specialised cyanobacteria that are specialised to perform nitrogen fixation.

Note that they are the same species as the other cyanobacteria they metabolically cooperate with.

170

What are biofilms?

Sheets of bacteria that metabolically cooperate.

171

What are archaea?

They are one of the three basic domains but and are most similar to bacteria.

172

What are the basic ways that archaea, bacteria and eukarya can be compared?

Structure, Chemical composition, genetics and tolerance

173

How do bacteria, archaea and eukarya compare in terms of structure?

Bacteria, Archaea, Eukarya

Nuclear envelope: absent, absent, present
Membrane-bound organelles: absent, absent, present

Circular chromosome: present, present, absent

174

How do bacteria, archaea and eukarya compare in terms of chemical composition?

Bacteria, Archaea, Eukarya

Peptidoglycan in cell wall: present, absent, absent
Membrane lipids: unbranched hydrocarbons, soem branched hydrocarbons, unbranched hydrocarbons
RNA polymerase: one kind, several kinds, several kinds.

175

How do bacteria, archaea and eukarya compare in terms of genetics?

Bacteria, Archaea, Eukarya


Initiator amino acid for protein synthesis: Formyl-methionine, methionine, methionine
Introns in genes: very rate, present in some, common
Histones associated with DNA: Absent, present in some species, present

176

How do bacteria, archaea and eukarya compare in terms of tolerance?

Bacteria, Archaea, Eukarya

Response to the antibiotics streptomycine and chloramphenicol: Growth inhibited, no effect, no effect

Growth at temperatures >100ºC: No, some species, no

177

What class of organism are all extremophiles?

Archaea

178

What are extremophiles?

Organisms (all archaea) that live in extreme environmental conditions

179

What are organisms that live in extreme environmental conditions called?

Extremophiles

180

What are the basic types of extremophiles?

Extreme halophiles and extreme thermophiles

181

What are extreme halophiles?

Those that live is extremely salty environments

182

What is the salinity of sea water?

3.5%

183

What are organism that live in very salty environments called?

Extreme halophiles

184

What are archae that release methane called?

Mathanogens

185

What are methanogens?

Archaea that release methane

186

What is a unique byproduct of respiration in some archaea?

Methane is produced by methanogens

187

What are the major groups of bacteria?

Proteobacteria, chlamydia, spirochetes, cyanobacteria and gram-positive bacteria

188

What are proteobacteria divided into?

Alpha proteobacteria, Beta proteobacteria, Gamma proteobacteria, Delta proteobacteria and Epsilon proteobacteria.

(all are subgroups)

189

Describe proteobacteria.

Gram-negative bacteria that photoautotrophs, chemoautotrophs, and heterotrophs. Some proteobacteria are anaerobic, while others are aerobic.

190

What bacteria are gram-negative?

All groups except the ‘Gram-positive group'

191

What are alpha proteobacteria?

Many are associated with eukaryotic hosts

For example Rhizobium (“root-nodule”) bacteria and Agrobacterium are alphas.

Mitochondria evolved from aerobic alpha proteobacteria through endosymbiosis.

192

What class of bacteria are Rhizobacteria?

Alpha proteobacteria

193

What class of bacteria is Agrobacterium?

Alpha proteobacteria

194

What class of bacteria is mitochondria derived from?

Alpha proteobacteria

195

What are beta proteobacteria?

A nutritionally diverse subgroup that includes Nitrosomonas, a genus of soil bacteria that play an important role in nitrogen recycling by oxidizing ammonium (NH4+), producing nitrite (NO2–) as a waste product.

196

What are gamma proteobacteria?

A sub-group that includes some some bacteria.

Many other members are pathogenic such as ’Salmonella’, ‘Legionella’ (cause Legionnaire’s disease ), Vibrio cholerae (cholera) and E. coli

197

What causes Legionaire’s disease?

Legionalla bacteria

198

What causes cholera?

Vibrio cholerae (a type of bacteria)

199

What does ‘Legionella’ bacteria cause?

Legionaire’s disease

200

What does ‘vibrio cholerae’ cause?

Cholera

201

What type of bacteria is Legionella?

Gamma proteobacteria

202

What type of bacteria is E. coli?

Gamma proteobacteria

203

What type of bacteria is salmonella?

Gamma proteobacteria

204

What type of bacteria is vibrio cholerae?

Gamma proteobacteria

205

What are photosynthetic bacteria classed as?

Cyanobacteria

206

Describe bacteria in the chlamydia group.

These parasites can survive only within animal cells, depending on their hosts for resources as basic as ATP.

The gram-negative walls of chlamydias are unusual in that they lack peptidoglycan

207

Describe spirochete bacteria?

They are helical (spiral shaped) heterotrophs

Many are free living but a few are parasistes

208

What is ‘phyloplankton’?

The collection of photosynthetic organisms that drift near the water's surface.

It includes organism of many types, including cyanobacteia

209

What are bacteria etc. that cause disease called?

Pathogens

210

What are pathogens?

Bacteria etc. that can cause disease

211

What does ’pathogenic bacteria’ refer to?

Bacteria that cause disease

212

Why is vibrio cholerae so harmful?

It releases an exotoxin that stimulates intestinal cells to release chloride ions into the gut, and water follows by osmosis.

213

What are harmful substance released by bacteria called?

Toxins

214

What are toxins?

Harmful substance released by bacteria etc.

215

What are toxins released by bacteria divided into?

Exotoxins and endotoxins

216

What are exotoxins?

Proteins secreted by certain bacteria and other organisms that cause harm

217

What are endotoxins?

Lipopolysaccharide components of the outer membrane of gram-negative bacteria.

They are released only when the bacteria die and their cell walls break down.

218

Is salmonella caused by an endotoxin or an exotoxin?

An endotoxin

219

What is an example of an endotoxin?

The one that causes salmonella poisoning

220

What is the use of organisms to remove pollutants from an environment called?

Bioremediation

221

What is bioremediation?

The use of organisms (including bacteria) to remove pollutants from soil, air, or water.