Chapter 4 Flashcards
(161 cards)
1
Q
Monomorphic vs pleomorphic
A
Monomorphic: Single shaped
Pleomorphic: Many shapes
2
Q
Average size of bacterial cell: ___ to ___ µm diameter, _ to _ µm length
A
0.2 to 2.0 µm diameter, 2 to 8 µm length
3
Q
T/F Most bacteria are pleomorphic
A
FALSE, most are monomorphic
4
Q
What are capsules made of?
A
sugars, polysaccharides
5
Q
-Capsule and Slime layers
-External to cell wall
– Many bacteria produce it, but not all
-Viscous, gelatinous, sticky
A
Glycocalyx
6
Q
_________: neatly organized, tightly attached, tight matrix; visible if treated with India ink
________: unorganized, loosely attached,
easily deformed
A
capsule
slime layer
7
Q
What are the 3 functions of glycocalyx?
A
–attachment to surfaces
– Prevents dehydration/dessication
– virulence
8
Q
What do capsules protect cells from?
A
- phagocytosis (eating) by immune cells
- help microbes adhere to body surfaces (attachment)
– Bacillus anthracis
– Streptococcus pneumoniae
– Klebsiella pneumoniae
9
Q
what structure assists swimming in Bacteria (Archaella in
Archaea)?
A
flagella
10
Q
Extracellular polymeric substance helps form what?
A
biofilms
11
Q
Function of biofilms
A
Protects cells, helps microbes attach to surfaces
– Streptococcus mutans
– Vibrio cholerae
12
Q
Bacteria Morphology
A
Bacillus
▪ Coccus
▪ Spiral
– Vibrio
– Spirillum
– Spirochete
▪ Star-shaped
▪ Rectangular
13
Q
These are characteristics of what?
– long, thin appendages (15–20
nm wide) anchored in cell at
one end
– tiny rotating machines that push
or pull through liquid
– Use propeller-like movements to push bacteria
A
flagella
14
Q
What are the 3 basic parts of flagellum structure?
A
Filament, hook, basal body
15
Q
The speed of flagella increases or decreases depending on what?
A
proton motive force
16
Q
What are the flagellar arrangements?
A
monotrichous: flagelli on one end
amphitrichous: flagelli on both ends
lophotrichous: flagelli grouped on one end
peritrichous: flagelli all over cell
17
Q
Axial filaments are also called ______
A
endoflagella
18
Q
Flagella allow bacteria to move toward or away from ______ (taxis)
A
stimuli
19
Q
Some flagella are important in bacterial __________, e.g. H. pylori penetration through mucous coat?
A
pathogenesis
20
Q
some flagella proteins are what and distinguish among serovars (e.g., Escherichia coli O157:H7?
A
H antigens
21
Q
fimbrae are hairlike appendages that
allow for what? They are involved in the formation of?
A
-allow for attachment
-involved in formation of biolfilms
22
Q
Where are axial filaments found?
A
Found in spirochetes
- Treponema pallidum (Syphilis);
- Borrelia burgdoferi (Lyme disease)
23
Q
Rigid structure that:
* Surrounds cytoplasmic membrane
* Determines the shape of bacteria
* Prevents cell from bursting
(Osmotic lysis
A
bacterial cell wall
24
Q
Rigidity of bacterial cell wall is due to
A
peptidoglycan (PTG)
- only in bacterial cell wall
25
T or F peptidoglycan has a common chemical structure?
false, it has a UNIQUE chemical structure
that distinguishes Gram- positive from Gram-negative
26
What domains are peptidoglycan (PTG) found in?
found only in bacteria
27
Basic structure of peptidoglycan ( 2 sugars)
* N-acetylglucosamine (NAG)
* N-acetylmuramic acid (NAM)
28
How is Peptidoglycan stabilized?
horizontal / vertical cross- links containing peptide interbridges
29
1._________interferes with the formation of the peptide cross-bridges that link the peptidoglycan rows, weakening the 2._______ _____
1. Penicillin
2. Cell wall
30
What is the structure of the gram-negative cell wall?
PTG is between outer
membrane and cytoplasmic
membrane
31
Gram positive cells all commonly have what acid that gives cell what type of charge?
teichoic acids
negative charge
32
T/F The outer membrane of gram-negative cell is impermeable to many things
TRUE
33
Transmembrane protein channels for entrance and exit of solutes
Porins
34
lipoteichoic acids and teichoic acids are _________ bound to
membrane lipids
covalently
35
What are the 3 representative genera of Gram+?
- Bacillus
- staphylococcus
- streptococcus
36
what is LPS: Gram-negative outer
leaflet membrane made of?
lipopolysaccharides not phospholipids
37
What are the 3 representative genera of Gram-?
- Escherichia
- Neisseria
- Pseudomonas
38
2 Medically significant portions of LPS
1. O-specific polysaccharide side chain
2. Lipid A
39
LPS (lipopolysaccharides) serves as barrier to what?
large number of molecules
40
Why is the O-specific polysaccharide side chain important?
Used to identify certain species or strains (E. coli refers to specific O-side chain)
41
Portion that anchors LPS molecule in lipid
bilayer
lipid A
42
Lack peptidoglycan
– Typically lack outer membrane
– Most lack polysaccharide wall, instead have S-layer
(protein shell)
Which cell wall is described above?
Archaeal cell wall
43
Lipid A is a toxic __________ and can cause pain, fever, and damage to blood vessels
endotoxin
44
What destroys peptidoglycan (PTG) that is
found in human secretions and has major defense against bacterial infection?
lysozyme
(cleaves glycosidic bond between sugars)
45
In methanogens, which cell wall is similar to peptidoglycan?
pseudomurein
46
Archaeal cell wall cannot be destroyed by what?
lysozyme and penicillin
47
Penicillin blocks the formation of what?
peptide bridges in peptidoglycan
48
Why are Gram- bacteria not susceptible to penicillin like Gram+ bacteria?
Outer membrane of Gram-negative cell wall blocks access of penicillin
49
Which atypical cell wall is described below?
– Lack cell walls
– Sterols in plasma membrane may protect cell from lysis
– Cause mild pneumonia
Mycoplasmas
50
acid-fast, mycoplasmas, and archaea all have what in common?
atypical cell walls
51
-Similar to Gram-positive cell walls (thick peptidoglycan)
– Waxy lipid (mycolic acid) bound to peptidoglycan
– Stain with carbolfuchsin
– Carbolfuchsin is not removed when rinsed with acid alcohol
acid-fast cell walls
52
Which atypical cell wall is described below?
- Walls of pseudomurein (lack NAM and D-amino acids)
Archaea
53
what are the two Acid-fast genera?
– Mycobacterium
– Nocardi
54
Why is the external structure so important?
- Many antibiotics target the cell wall
-An outer membrane complicates treatment with antibiotics
- allow for attachment to certain surfaces and gives structure
55
Define Plasma membrane
Surrounds cytoplasm and separates the cytoplasm from environment
56
What do Bacterial and eukaryotic cytoplasmic membranes have in common?
phospholipid bilayer
containing embedded proteins.
57
What is the main function of the plasma membrane?
selective permeability (nutrients
transported in and waste products out)
58
What do membrane proteins do in the plasma membrane?
facilitate reactions and
function in energy metabolism
59
What do phospholipids contain?
- hydrophobic (water-repelling) components
- hydrophilic (water-attracting) components
60
Each phospholipid contains what 2 things?
hydrophilic phosphate head and
hydrophobic fatty acid tail
61
T or F Proteins are not
stationary and are constantly changing position for various function hence the fluid mosaic model?
True
62
hydrophilic (head) = _______ + _________ and another
functional group
hydrophilic (head) = glycerol + phosphate and another
functional group
63
hydrophobic (tails) = ______ _____
Fatty acids
64
Membrane is embedded with numerous what that can function as receptors, transport gates, a mechanism to sense surroundings, etc?
proteins
65
______________: are on the inner or outer surface of the plasma membrane and loosely attached
___________: integral membrane proteins
____________: extend completely across
membrane
peripheral membrane
proteins
embedded proteins
Transmembrane proteins
66
T or F the Cytoplasmic membrane is permeable to anything?
False, it is “selectively permeable”
67
What are the 3 major functions of the plasma membrane?
1. permeability barrier
2. protein anchor
3. energy conservation
68
_____________: substances move from high concentration to low concentration; no energy
expended
____________: substances move from low concentration to high concentration; energy
expended
Passive Transport
Active Transport
69
Energy conservation and consumption (METABOLISM) helps with what?
* proton motive force (PMF)
* enzymes for ATP production
70
protein anchor does what?
Holds proteins in place.
71
Archaeal cytoplasmic membranes have
what type of linkages in phospholipids of Archaea?
– Ether linkages
72
Simple diffusion, facilitated diffusion, and osmosis are all examples of which type of transport?
Passive Transport
73
Define facilitated diffusion
Movement of ions or larger
molecules across the membrane.
- move WITH concetration gradient
74
Bacteria and Eukarya have what type of linkages in phospholipids?
ester linkages
75
Archaeal lipids have what instead of fatty
acids?
isoprenes instead
76
movement of a solute from an area of high
concentration to an area of low concentration until evenly distributed
Simple diffusion
77
In osmosis:
more water =
less water=
more water = less solute
less water= more solute
78
the net movement of water across
a selectively permeable membrane
from an area of higher water
concentration (lower solute
concentration) to an area of lower
water concentration (higher solute
concentration)
osmosis
79
Inflow of water exerts osmotic pressure on membrane. Membrane rupture is prevented by?
rigid cell wall of bacteria
80
Match the word with the definition: hypotonic, hypertonic, isotonic
* __________: solute concentrations inside
and outside of cell is same; water is at equilibrium– No net movement of water
* ___________: solute concentration is lower
outside than inside the cell; water moves into cell
* ___________: solute concentration is
higher outside of cell than inside; water moves out of cell
* Isotonic: solute concentrations inside
and outside of cell is same; water is at equilibrium– No net movement of water
* Hypotonic: solute concentration is lower
outside than inside the cell; water moves into cell
* Hypertonic: solute concentration is
higher outside of cell than inside; water moves out of cell
81
The thick, aqueous, elastic, semitransparent substance
inside the plasma membrane
Cytoplasm
82
Some disinfectants damage the plasma
membrane what are they?
– Alcohols
– Quaternary ammonium compounds
(detergents)
83
Some antibiotics damage the plasma membrane name one?
– Polymyxin
84
What is the cytoplasm made of?
Eighty percent water plus proteins, carbohydrates, lipids,
and ions
85
Damage to plasma membrane causes what?
leakage of cell contents
86
T/F Cytoplasm has DNA (nucleoid), ribosomes, and inclusions
TRUE
87
which bacterial cell internal structures are essential for life?
– Chromosome
– Ribosome
- cell wall and membrane (but these are outer structures)
88
The cytoskeleton in the cytoplasm functions in what 4 things?
– Cell division
– Maintaining cell shape
– Growth
– DNA movement
89
Internal structures of Bacterial Chromosome/Nucleoid
1. where is it?
2. how many chromosomes?
3. shape?
4. does it contain all genetic
information? (Y/N)
5. Does it have a membrane and proteins?
1. cytoplasm
2. single chromosome
3. Circular, double-stranded
molecule
4. YES
5. NO membrane and proteins
90
what internal structures are optional and can confer selective advantage?
– Plasmid
– Storage granules
– Endospores
91
name the internal structure?
– small extrachromosomal
circles of DNA
* Generally 0.1% to 10% the size
of a chromosome (5-100 genes)
– Outside of the chromosome
* Independently replicating
– Encode characteristic
plasmids
92
what are potential enhances of survival in plasmids even though they are not necessary for life?
– Antimicrobial resistance
– Production of toxins
93
When the vegetative cell differentiates to a nongrowing,
heat-resistant, light-refractive structure what is it called?
Endorspore sporulation
94
In which 2 cells and cell structure are ribosomes present?
Prokaryotes, eukaryotes, and cytoplasm
95
What is the function of ribosomes?
protein synthesis
96
What are ribosomes made of?
Made of protein and ribosomal RNA
* (Prokaryotic) 70S:
* Eukaryotic 50S large + 30S small subunits
97
What are the three steps in germination?
activation, germination, and outgrowth
98
Specialized spores that are resistant to desiccation, heat, radiation, chemicals
endospores
99
this is considered what type of mechanism?
Vegetative → Endospore → Vegetative
A survival mechanism; not a reproductive process
100
* __________: endospore formation
* ___________: endospore returns to vegetative state
sporulation
germination
101
endospores are ideal for dispersal via?
wind, water, or animal gut
102
endospores are produced by members of what bacteria?
Bacillus and Clostridium (Gram-positive)
102
What is germination triggered by?
Nutrient availability
103
What special stain is used for germination?
malachite green
103
*Bacteria in vegetative state
sense ______ and begin
sporulation.
*Vegetative cell will
___ while the spore
remains
* Spore will go back
to vegetative cell
when ________
___________ return
starvation
die
favorable conditions
104
Eukaryotic plasma membrane is similar in chemical structure and function of cytoplasmic membrane of prokaryote in what way?
Phospholipid bilayer embedded with proteins
105
__________: Spore is at the end of the bacteria
__________: Spore is towards the end but not fully
__________: Spore is centered
Terminal
Subterminal
Central
105
Eukaryotic plasma Membrane contains _________ for strength
* Animal cells contain _________
* Fungal cells contain ________
sterols
cholesterol
ergosterol
106
what are the difference in sterols?
target for antifungal medications
107
– Nucleus
– Ribosomes
– Endoplasmic
reticulum
– Golgi apparatus
– Lysosome and
vacuoles
– Mitochondria and
chloroplasts
– Peroxisomes
– microtubules, and
microfilaments.
– Flagella and cilia
In eukaryotic cells all of these are membrane bound? (T/f)
False, all are membrane bound except
– microtubules, and
microfilaments.
– Flagella and cilia
107
DNA molecules are wrapped around proteins to form fibers called what?
Archaea also contain histones and nucleosomes; related to
__________?
chromatin / nucleosomes
eukarya
108
What is the chemical structure of the plasma membrane?
Phospholipid bilayer
108
what is produced in the nucleolus?
ribosomes
109
Each very long chromatin fiber twists and folds to form a condensed ___________?
chromosome
110
Define nucleus
Double membrane structure (nuclear envelope) that
encloses the cell’s DNA
110
what forms the folds of the mitochondrion?
cristae
111
when one species lives inside another host
species (think of “Pac Man”
endosymbiosis
112
which 2 organelles specialize in energy metabolism and have an endosymbiotic origin?
mitochondria and chloroplasts
113
The nucleus is enclosed by what two membranes?
nucleoplasm
(inner membrane) and cytoplasm (outer membrane)
113
DNA is complexed with ________ proteins to form
________ / __________
histone
chromatin
nucleosomes
113
the individual disks in chloroplasts are called what?
thylakoids
114
where do light reactions occur in the chloroplasts?
thylakoids
115
What happens to chromatin during mitosis and meiosis?
it condenses into chromosomes
115
Mitochondria and chloroplasts contain circular DNA _______ and ________ (70S) similar to those of ________
genomes and ribosomes (70S) similar to those of Bacteria
116
The nucleus contains a
darker area called a
_____________
nucleolus
116
Mitochondria and chloroplasts are the only 2 organelles that have their own ____ and replication?
DNA
118
A particular location within
the nucleus where ribosomes are made
Nucleolus
119
DNA > RNA
RNA > DNA
Transcription
Translation
121
What 2 things occur inside of the mitochondria?
cellular respiration and oxidative
phosphorylation for aerobic eukaryotes
122
Oxidative Phosphorylation uses _______ to harvest ________(ATP) from sugar molecule
oxygen
energy (ATP)
123
________: folded internal membranes
▪ contain enzymes needed for respiration and ______ production
– ________ : innermost area of mitochondrion
▪ contains ______ acid enzymes
Cristae: internal; respiration & ATP
Matrix: citric acid
124
What is the Energy Currency of Cell?
ATP (Adenosine Tri-Phosphate)
125
Cloroplasts is a chlorophyll-containing organelle found in what?
Phototrophic eukaryotes and Algae cyanobacteria
126
Where is the site of photosynthesis (the energy of sunlight in combination with
water and carbon dioxide is used to create molecules of sugar)?
Chloroplasts
129
In chloroplasts the inner membrane surrounds ____, which contains large amounts of RuBisCO (key enzyme for ________ cycle that converts CO2 organics
stroma
RuBisCO
Calvin Cycle
CO2
133
__________: flattened membrane discs contain chlorophyll and
ATP synthetic components, form proton motive force
thylakoids
135
The ____________ and ___________likely originated from endosymbiosis
Mitochondria
chloroplasts
136
Eukarya are hypothesized to have originated from what type of fusion of archaeal host and mitochondrial endosymbiont?
symbiotic fusion
137
Define endosymbiosis
when one species lives inside another host species
138
Rough ER has what that Smooth ER doesn't??
Rough ER contains attached ribosomes; smooth does
not
139
name the organelle:
Transport organelle
* Modifies proteins produced by rough ER
* Finishes, sorts, and ships cell products (FedEx of Cell)
* Transports modified proteins via secretory vesicles to the plasma membrane and other regions
Golgi apparatus
140
what 4 things does the Golgi apparatus produce?
glycoproteins, lipoproteins, glycolipids, and lysosomes
141
What are the two functions of the smooth ER?
1. synthesis of lipids (fats,
steroids, hormones)
2. carbohydrate metabolism
142
Flagella and Cilia Projections are used for what?
locomotion or moving substances along the cell surface
143
What does the Rough ER produce?
glycoproteins and new membrane material
144
Lysosomes are present in phagocytic cells and contain what 2 things?
digestive enzymes and recycling cell components
145
* Flagella-long projections; ____ in number
* Cilia-short projections; _________
– Structurally and functionally differ from prokaryotic flagella
Flagella-long projections; few in number
Cilia-short projections; numerous
146
flagella and cilia are in ___________ cell structures while fimbriae, pili, AND flagella are in __________ (bacteria) cell structures
eukaryotic
prokaryotic
147
The cytoskeleton is a network of protein fibers that provides what 3 functions?
Cytoskeleton
1. mechanical support
2.anchorage
3. reinforcement
148
what provides internal structural support in eukaryotic cells?
Cytoskeleton
149
Microtubules 3 functions
1. maintain shape
2. facilitate motility
3. move chromosomes and organelles
150
Microtubules are hollow tubes 25 nm in diameter; composed of α- and β-tubulin
and aid in what 3 things?
cell shape
facilitate motility
move chromosomes and organelles
151
What structure of the cytoskeleton maintain and change cell shape; involved in amoeboid motility
and cell division?
microfilaments
152
Intermediate filaments maintain and position what?
maintain cell shape and position organelles
153
What is the size of prokaryotic and eukaryotic cells?
P: 0.2-2.0 µm in diameter
E: 10-100 µm in diameter
154
microfilaments are 7 nm in diameter; polymers of actin protein aid in what 3 things?
change cell shape
involved in amoeboid motility
cell division
155
Are membrane bound organelles absent or present in prokaryotic and Eukaryotic cells?
P: Absent
E: Present
156
intermediate filaments are 8–12 nm in diameter; fibrous keratin proteins maintain what?
cell shape and position organelles
157
What is the cell wall made of in prokaryotes?
* Peptidoglycan (bacteria)
* Pseudomurein (archaea)
158
What is the cell wall made of in eukaryotes?
Cellulose & Chitin
159
What is the number of ribosomes in prokaryotes and eukaryotes?
P: 70s
E: 80s
