Lecture 2 (bacterial Cell structure with some Archaea stuff) Flashcards Preview

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Flashcards in Lecture 2 (bacterial Cell structure with some Archaea stuff) Deck (242):
1

Prokaryotes differ from eukaryotes in size and _____

simplicity

2

most prokaryotes lack

internal membrane systems

3

is the term prokaryotes becoming blurred

yes

4

prokaryote comes form the Greek words for

pre-nucleus

5

Eukaryote comes form the Greek words for

true nucleus

6

Are most bacteria monomorphic

Yes

7

What does monomorphic mean

one shape

8

Are a few bacteria pleomorphic

yes

9

what does pleomorphic mean

multiple shapes

10

What are the three basic bacteria shapes

-Bacillus (rod-shaped)
- Coccus (spherical)
- Spiral

11

what are the three types of spiral shapes


-Spirillum
- Vibrio
- Spirochete

12

What is Spirillum

Spiral shaped with one or more twists

13

What is Vibrio

type of Spiral shaped
-Curved rod

14

What is Spirochete

-Type of Spiral shape

-Flexible, helical, spirals

15

Diplo-

pairs

16

Staphylo-

Clusters

17

Strepto-

Chains

18

The division in staphylo- is in _____ planes

multiple

19

The division in Strepto- is in ____ planes

a single plane

20

Organisms that are variable in shape

pleomorphic

21

Network of long, multinucleate filaments

mycelium

22

what is the smallest bacteria

Mycoplasma (0.3 micrometers)

23

The average rode size

1.1-1.5 x 2-6 micrometers
(size of E. coli)

24

Epulopiscium fishelsoni is a ___ (size) bacteria

very large - 600 x 80 micrometers

25

____ cells have a larger surface area to volume ratio

smaller cells

26

Function of plasma membrane in bacteria

-Selectively permeable barrier
-Mechanical boundary of cell
- Nutrient and waste transport
- location of many metabolic processes (respiration, photosynthesis)
- detection of environmental cues for chemotaxis

27

What is the function of the Gas Vacuole in bacteria

an inclusion that provides buoyancy for floating in aquatic environments

28

What is the function of the ribosomes in bacteria

Protein Synthesis

29

What is the function of inclusions in bacteria

storage of carbon, phosphate, and other substances

30

What is the function of nucleotide in bacteria

localization of genetic material (DNA)

31

What is the function of Periplasmic space in bacteria

-in typical Gram-negative bacteria, contains hydrolytic enzymes and binding proteins for nutrient porcessing and uptake

- In typical Gram-positive bacteria it may be smaller or absent

32

what is the function of the cell wall in bacteria

-protection form osmotic stress
- helps maintain cell shape

33

What is the function of Capsules and slime layers in bacteria

-Resistance to phagocytosis
- Adherence to surfaces

34

What is the function of Fimbriae and pili in bacteria

-Attachement to surfaces
- bacterial conjugation and transformation
- Twitching and gliding motility

35

What is the function of Flagella in bacteria

- Swimming and Swarming motility

36

What is the function of endospore in bacteria

Survival under harsh environmental conditions

37

What are the components of the bacterial cell envelope

-Plasma membrane
- Cell wall
- Layers outside the cell wall

38

do some bacteria have an internal membrane system

yes

39

is a plasma membrane an absolute requirement for all living organisms

yes

40

Bacterial membranes lack _______, which is present in Eukaryotic membranes but they do contain _____

sterols (like cholesterol), but do contain Hopanoids

41

What is the function of Hopanoids in the bacterial membranes

is a sterol-like molecule and stabilizes the membrane

42

are Hopanoids found in petroleum

yes

43

Lipid composition of bacterial membranes varies with

environmental conditions (ex. Temperature)

44

do many bacteria have plasma membrane infoldings

yes

45

some Archaeal membranes have a ____ structure instead of a bilayer structure

monolayer

46

Are Archaeal membranes composed of lipids that differ chemically from those of Bacteria and Eukaryotes

Yes

47

bacterial and eukaryotic lipids contain ___ bonds while Archaeal lipids contain ____ bonds

Ester, Ether

48

bacterial and Eukaryotic lipids have ___ hydrocarbons attached to glycerol

2

49

special features of Archaeal lipids

-Ether bonds
- Branched molecules
- Tetraethers (some) (note these make a monolayer)

50

what are the functions of the Plasma membrane

-Encompasses the cytoplasm
- Selectively permeable Barrier
- Interacts with External environment
- receptors for detection of and response to chemical surroundings
- Transport systems
- Metabolic processes

51

Substance in which nucleotide, ribosomes, inclusion bodies, plasmids, and cytoskeletal filaments are suspended

Cytoplasm of Bacteria and Archaea

52

The cytoplasm of bacteria and Archaea lack _____ and are composed largely of ___

-lack organelles bound by unit membranes
-composed largely of water

53

Homologs of all 3 eukaryotic cytoskeletal elements have been identified in bacteria. What are they

-Actin
-Intermediate filaments
- Microtubules

54

Are the functions of the cytoskeleton in bacteria similar to in eukaryotes

yes

55

Function of microtubule homolog FtsZ in Bacteria

Cell division

56

Microtubule homolog FtsZ is widely observed in

bacteria and archaea

57

Function of microtubule homolog BtubA/BtubB in Bacteria

Unknown

58

microtubule homolog BtubA/BtubB is only observed in ____ and thought to be encoded by

Only observed in Prosthecobacter spp
thought to be encoded by eukaryotic tubular genes obtained by horizontal gene transfer

59

Function of microtubule homolog TubZ in bacteria

Possibly plasmid segregation

60

Microtubule homolog TubZ is encoded by ____ and observed in

large plasmids and observed in members of the genus Bacillus

61

Function of actin homolog MamK in bacteria

Positioning magnetosomes

62

Function of actin homolog MreB/Mbl in bacteria

Helps determine cell shape
may be involved in chromosome segregation
localizes proteins

63

Function of actin homolog ParM in bacteria

Plasmid Segregation

64

Actin homolog MamK is observed in

magnetotactic species

65

Actin homolog MreB/Mbl is observed in

Most rod-shaped bacteria

66

Actin homolog ParM is ____ encoded

plasmid

67

function of intermediate filament homolog CreS (Crescentic)

Induces curvature in curved rods

68

Intermediate filament homolog CreS (crescentin) is observed by

Caulobacter crescentus

69

What are two unique bacterial cytoskeletal proteins

MinD and ParA

70

What is the function of the unique bacterial cytoskeletal protein MinD

prevents polymerization of FtsZ at cell poles

71

What is the function of the unique bacterial cytoskeletal protein ParA

Segregates chromosomes and plasmids

72

The unique bacterial cytoskeletal protein MinD is observed in

Many rod-shaped bacteria

73

The unique bacterial cytoskeletal protein ParA is observed in

many species including Vibrio cholerae, C. crescentus, and Thermus themophilus

74

Microtubule homolog FtsZ is observed in ____ and forms

many bacteria and forms ring during septum formation in cell division

75

Actin homolog MreB is found in ____ and not ___ and maintains

found in bacilli and not cocci
maintains shape by positioning peptidoglycan synthesis machinery

76

Intermediate filament homolog CreS is rare, and maintains

curve shape

77

Inracytoplasmic membranes can be seen as plasma membrane infolding in

-many photosynthetic bacteria
-many bacteria with high respiratory activity

78

what is Anammoxosome in Plantomycetes

-an Intracytoplasmic Membrane
- An organelle that is the site of anaerobic ammonia oxidation

79

What are inclusions

granules of organic or inorganic material that are stockpiled by the cell for future use

80

what are some storage inclusions

-Storage of nutrients, metabolic end products, energy, building blocks
- Glycogen storage
- Carbon Storage
- Poly-beta-hydroxybutyrate (PHB)
- Glycogen
- Phosphate-Polyphosphate granules (Volutin)
- Amino Acids- cyanophycin granules
- Sulfur Granules

81

Sulphur granules are important in bacteria that don't use

water

82

Gas vacuoles are found in

aquatic, photosynthetic bacteria and archaea

83

Gas Vacuoles are Aggregates of hollow cylindrical structures called

gas vesicles

84

Function of Gas Vacuoles

Provide buoyancy in gas vesicles

85

Magnetosomes are found in ____ bacteria

aquatic

86

what are the function(s) of magnetosomes

magnetite particles (iron) for orientation in Earth's magnetic field

87

Cytoskeletal protein ____ helps form magnetosome chain

MamK

88

Microcompartments in bacteria are not bound by membranes but ________ for specific function

compartmentalized

89

What are carboxysomes

Microcompartments in CO2 fixing bacteria
- contain the enzyme ribulose-1,5-Bisphosphate carboxylase (Rubisco), enzyme used for CO2 fixation

90

complex protein/RNA structures that are the sites of protein synthesis

Ribosomes

91

What is the size of bacterial and archaea ribosomes

70S

92

What is the size of Eukaryotic ribosomes

80S

93

What does the S in 80S ribosome stand for

Svedburg unit

94

What are the Bacterial ribosomal RNA subunits

-16S small subunit
- 23S and 5S in large subunit

95

The nucleoid of bacteria is usually not _____ bound

membrane bound (there are a few exceptions)

96

____ is the location of chromosome and associated proteins in Bacteria

Nucleoid

97

The nucleoid of bacteria usually 1

closed circular, double stranded DNA molecule

98

_____ and ______ (different from histones) aid in folding of DNA in bacteria

Supercoiling and nucleoid proteins

99

Characteristics of Prokaryotic Chromosome

-Usually a circular, double-stranded DNA molecule
- Usually only one
- Looped and coiled extensively

100

what are plasmids

-extrachromosomal DNA
- Found in bacteria, archaea, and some fungi
- usually small, closed circular DNA molecules
- Exist and replicate independently of chromosome
- Episomes- may integrate into chromosome
- inherited during cell division
- Contain few genes that are non-essential
- confer selective advantage to host (e.g., drug resistance)
- Classification based on mode of existence, spread, and function

101

Plasmids are found in

bacteria, archaea, and some fungi

102

plasmids exist and replicate _____ of the chromosome

independently

103

function of conjugative plasmids

Transfer of DNA form one cell to another

104

Example of conjugative plasmids

F factor

105

Phenotypic features of conjugative plasmids

-Sex pilus
- Conjugation

106

Hosts for conjugative Plasmids

-E. coli
-Salmonella
- Citrobacter

107

What is the function of R plasmids

carry antibiotic-resistance genes

108

What is an example of R plasmids

RP4

109

What are the hosts of R plasmids

-Pseudomonas
- many other gram-negative bacteria

110

What are the phenotypic features of R plasmids

-Sex pilus
- Conjugation
- resistance to Amp, Km, Nm, Tet

111

Function of Col plasmids

produce bacteriocins, substances that destroy closely related species

112

host(s) of Col plasmids

E. coli

113

Phenotypic features of Col Plasmids

Colicin E1 production

114

Function of Virulence Plasmids

Carry virulence genes

115

Example of Col Plasmids

ColE1

116

Example of virulence plasmids

Ti

117

Hosts of Virulence plasmids

-Agrobacterium tumefaciens

118

Phenotypic features of virulence plasmids

-Tumor induction in plants

119

Function of metabolic plasmids

-carry genes for enzymes

120

Example of metabolic plasmids

CAM

121

Hosts of metabolic plasmids

Pseudomonas

122

Phenotypic features of Metabolic Plasmids

Camphor degradation

123

Rigid structure that lies just outside the cell plasma membrane

Peptidoglycan (murein)

124

Stain purple, thick peptidoglycan

Gram-Positive Bacteria

125

Stain pink or red; thin peptidoglycan and outer membrane

Gram-Negative Bacteria

126

what are the functions of the cell wall

- Maintains shape of the bacterium
- almost all bacteria have one
- Helps protect cell from osmotic lysis
- Helps protect from toxic materials
- may contribute to pathogenicity

127

Peptidoglycan is a meshlike polymer of identical subunits forming long strands. Two alternating sugars ____ and ___ and alternating ___ and ____ amino acids


-Two alternating sugars
- N-acetylglucosamine (NAG)
- N-acetylmuramic acid
- 4 alternating D- and L- amino acids

128

Chains of peptidoglycan subunits are joined by _______ between the peptides

cross-links (covalent bonds)

129

What are the three amino acids found in peptidoglycan that are not found in proteins

- D-glutamic acid
- D-alanine
- meso-diaminopimelic acid

130

What is the importance of D-amino acids in peptidoglycan

protects against degradation by most peptidases, which recognize only the L-isomers of amino acid residues

131

What are the four amino acids that alternate in the structure of peptidoglycan

- L-Alanine
- D- Glutamic acid
- Meso-Diaminopimelic acid
- D- Alanine

132

The pentapeptide side chain of peptidoglycan terminates with

two D-alanines

133

Peptidoglycan strands have a ____ shape

helical

134

Peptidoglycan chains are cross linked by _____ for strength

peptides

135

bacteria can cross-link the strands by connecting the carboxyl group of the _____ at position 4 directly to the amino group of _______ (position 3) of the other strand ( the position 5 ______ is removed as the cross-link is formed)

D-Alanine, diamiopimelic acid, D-Alanine

136

A peptide interbridge is composed of ____ and goes from ___ of one strand to ___ on the other strand

5 glycines, D-alanine, L-lysine

137

Peptidoglycan sacs are _____ networks

interconnected

138

Peptidoglycan chains cross-linking is common in

Gram-negative bacteria

139

Gram positive cell walls are composed primarily of

peptidoglycan

140

Gram positive cell wall are primarily composed of peptidoglycan and may also contain _____

teichoic acid (which is negatively charged)

141

What is the function of teichoic acids in the cell walls of gram-positive cell walls

-Helps maintain cell envelope
- Protect from environmental substances
- may bind to host cells

142

Do some gram-positive bacteria have layer of proteins on surface of peptidoglycan

yes

143

The periplasmic space of Gram positive bacteria lies between ___ and ____ and is ___ than that of Gram-negative bacteria

plasma membrane and cell wall and is smaller than that of Gram negative bacteria

144

The periplasm of gram positive bacteria has relatively few _____

proteins

145

Enzymes secreted by Gram-positive bacteria are called

exoenzymes

146

Exoenzymes, which are secreted by gram-positive bacteria aid in

degradation of large nutrients

147

which has more complex cell walls gram-negative or gram-positive bacteria

Gram-negative

148

The cell wall of gram-negative bacteria consists of a ____ layer of peptidoglycan surrounded by an

thin layer of peptidoglycan surrounded by an outer membrane

149

The outer membrane of gram-negative cell walls is composed of

lipids, lipoproteins, and lipopolysaccharide (LPS)

150

Does the cell wall of gram-negative bacteria have teichoic acids

no

151

In gram-negative cell walls peptidoglycan is about ______% of cell walls weight

5-10%

152

The periplasmic space of gram-negative cell walls may constitute ______% of cell volume

20-40%

153

the periplasmic space of gram-negative cell walls have many enzymes present such as

hydrolytic enzymes, transport proteins and other proteins

154

The outer membrane of gram-negative cell walls lays outside the

thin peptidoglycan layer

155

_____ connect outer membrane to thin peptidoglycan layer of gram-negative bacteria

Braun's Lipoproteins

156

Lipopolysaccharide (LPS) consists of three parts. What are they

-Lipid A
- Core polysaccharide
- O side chain (O antigen)

157

Lipid A is embedded in the

outer membrane

158

Core polysaccharide, O side chain extend

out from the cell

159

Importance of LPS

-Contributes to negative charge on cell surface
- Helps stabilize outer membrane structure
- May contribute to attachment to surfaces and biofilm formation
- Creates a permeability barrier
- Protection form host defenses (O antigen)
- Can act as an endotoxin (Lipid A)

160

What acts as an endotoxin in gram-negative bacteria

Lipid A

161

What is the function of the O antigen in gram-negative bacteria

protection from host defenses

162

The Gram-negative outer membrane is more permeable than plasma membrane due to presence of ______ and _____

Of porin protein and transporter proteins

163

Porin proteins in the outer membrane of gram-negative bacteria let ______ molecules (_____daltons) pass

small (600-700 daltons)

164

Solute concentration outside the cell is less than inside the cell

hypotonic environment

165

In a hypotonic environment water moves

into the cell and the cell swells

166

The function of the cell wall in a hypotonic environment is that it

protects the cell from lysis

167

Solute concentration outside the cell is greater than inside

Hypertonic environments

168

In a hypertonic environment water ______ the cell

leaves

169

what is plasmolysis

when the plasma membrane shrinks but the cell wall remains the same

170

_____ breaks the bond between N-acetyl glucosamine and N-acetylmuramic acid

Lysozyme

171

Penicillin inhibits _____ synthesis

peptidoglycan

172

Cells that lose a cell wall may survive in _____ environments

Isotonic

173

Mycoplasma does not produce a _____

cell wall

174

Mycoplasma does not produce a cell wall but their _______ is more resistant to osmotic pressure. Why

Plasma membrane. Because it has cholesterol in it

175

examples of cells without cell wall

- Protoplasts
- spheroplasts
- Mycoplasma

176

Archaeal cell walls lack peptidoglycan but some have ______ also called ____

pseudopeptidoglycan, also called pseudomurein

177

Components outside of the cell wall

-Outermost layer in the cell envelope
- Glycocalyx
- capsules and slime layers
- S layers
- Aid in attachment to solid surfaces
- e.g. biofilms in plants and animals

178

Capsules and slime layers aid in attachment to _____

solid surfaces

179

Capsules are usually composed of

polysaccharides

180

Capsules are well organized and _____ removed form the cell

not easily

181

Are capsules visible via light microscope

yes

182

What are the protective advantages of capsules

-Resistant to phagocytosis
- Protect from desiccation
- Exclude viruses and detergents

183

Slime layers are similar to capsules except ____, _____ and ____

diffuse, unorganized and easily removed

184

Slime layers may aid in

motility

185

S layers are regularly structured layers of ____ or ____ that ____-

protein or glycoprotein that self-assemble

186

In gram-negative bacteria the S layer adheres to _____

outer membrane

187

In Gram-Positive bacteria the S layer is associated with the ________ surface

peptidoglycan surface

188

Functions of S layer

-Protect from ion and pH fluctuations, osmotic stress, enzymes, and predation
- Maintains shape and rigidity
- Promotes adhesion to surfaces
- Protects from host defenses
- Potential use in nanotechnology
- S layer spontaneously associates

189

Examples of external structures that extend beyond the cell envelope in bacteria

-Pili and fimbriae
- Flagella

190

Function of external structures that extend beyond the cell envelope in bacteria

- Protection

- Attachement to surfaces

- Horizontal gene transfer

- cell movement

191

short, thin, hairlike, proteinaceous appendages (up to 1,000/cell) that can mediate attachment to surfaces

Fimbriae (s. fimbria) ; Pili (s. Pilus)

192

Some (type ____ fimbriae) required for twitching motility or gliding motility that occurs in some bacteria

IV

193

Long, thicker, and less numerous (1-10/cell) and is required for conjugation (mating)

sex pili (s. Pilus)

194

Genes for formation of sex pili are found on

plasmid

195

Threadlike, locomotor appendages extending outward from plasma membrane and cell wall

Flagella

196

Functions of Flagella

-Motility and swarming behavior

- Attachment to surfaces

- May be virulence factors

197

A bacterial flagella has an ultrastructure composed of ____ parts

three

198

What are the three parts of a bacterial flagella

-Filament

- Hook

- Basal body

199

Bacterial flagella are thin, rigid protein structure that cannot be observed with bright-field microscope unless specially

stained

200

The filament of bacterial flagella extends form _____ to the ___

cell surface to the tip

201

The filament of bacterial flagella is a ____, ____ cylinder of ______ protein

Hollow, rigid cylinder of flagellin protein

202

The hook of bacterial flagella links ____ to ____

filament to basal body

203

The basal body of flagella is a series of ___ that _____

rings that drive flagellar motor

204

Flagellar synthesis

- Complex process involving many genes/gene products

-New flagellin molecules transported through the hollow filament using type III-like secretion system

- Filament subunits self-assemble with help of filament cap at time, not base

205

New flagellin molecules transported through the hollow filament using _____- like secretion system

Type III

206

Filament subunits self-assemble with help of _____ at ___, not ___

filament cap at tip, not base

207

Monotrichous

One flagellum

208

Polar flagellum

flagellum at end of cell

209

Amphitrichous

one flagellum at each end of cell

210

Lophotrichous

cluster of flagella at one or both ends

211

Peritrihous

Spread over entire surface of cell

212

bacteria and archaea have direct movement. Name them

Directed

- Flagellar movement

- Spirochete motility

- Twitching motility

- Gliding motility

213

What is movement toward chemical attractants such as nutrients, and away from harmful substances called

Chemotaxis

214

Bacteria and archaea move in response to ____, ____, _____, and ___

temperature, light, oxygen, osmotic pressure, and gravity

215

In general a bacterial flagellum counterclockwise (CCW) rotation causes _____ motion (run)

forward

216

In general a bacterial flagellum clockwise rotation (CW) causes

disrupts run causing cell to stop and tumble

217

____ and ____ create a channel through which protons can flow. This causes the flagellum to rotate

MotA and MotB

218

Bacterial flagellum is a ____ part motor producing torque

2

219

The rotor of the flagellum is composed of _____ and ____, which turn and interact with strator

C (FliG protein) ring and MS ring

220

The Strator of a flagellum is composed of _____ and _____ proteins

Mot A and Mot B

221

The strator of flagellum form channel through ___

plasma membrane

222

Protons move through ____________ using energy of proton motive force

Strator (Mot A and Mot B)

223

Torque powers rotation of the _____ and ____

basal body and filament

224

Spirochete motility

- Multiple flagella form axial fibril which winds around the cell

- Flagella remain in periplasmic space inside outer sheath

- Corkscrew shape exhibits flexing and spinning movements

225

Twitching and Gliding motility may involve _____ and ___-

type IV pili and slime

226

Explain twitching motility

- Pili at ends of cell
- short, intermittent, jerky motions
- cells are in contact with each other and surface

227

Explain gliding motility

smooth movements

228

Movement toward a chemical attractant or away form a chemical repellent

chemotaxis

229

changing concentrations of chemical attractants and chemical repellent bind _____ of chemosensing system

chemoreceptors

230

in presence of attractant tumbling frequency is _________ and runs in direction of attractant are ____

intermittently reduced, longer

231

Behavior of bacterium is altered by _____ concentration of chemical

temporal

232

Chemotaxis away from a repellent involves ____ tumbling frequency and run is intermittently ___

longer, reduced

233

Complex, dormant structure formed by some bacteria

Bacterial endospore

234

Endospores are resistant to

-heat

-Radiation

- Chemicals

- Desiccation

235

Endospore structure is a spore surrounded by thin covering called _____

exosporium

236

thick layers of ____ form the spore coat

protein

237

The cortex, beneath the coat of the endospore, is made of ______

thick peptidoglycan

238

The core of the endospore has ____ and ___

nucleoid and ribosomes

239

What makes an endospore so resistant

- calcium (complexed with dipicolinic acid)

- Small, acid-soluble, DNA-binding proteins (SASPs)

- Dehydrated core

- Spore coat and exosporium protect

- DNA repair enzymes

240

Process of endospore formation

Sporulation

241

Sporulation occurs in

hours (up to 10 hours)

242

Sporulation normally commences when growth ___ because of lack of ____

ceases, nutrients