Chapter 4: Prokaryotic cells - Bacteria Flashcards
1
Q
when did prokaryotic cells emerge?
A
3.5 billion years ago
2
Q
pilus characteristics
A
- long filament used for genetic recombination; conjugation
- contains ~4,000 genes
- provides genetic variety for bacteria
- generally responsible for antibiotic resistance
- hollow part transfers piece of DNA from one bacterium to the other
3
Q
plasmid characteristics
A
- small independent pieces of DNA
- contain resistant genes
- used in genetic engineering
4
Q
what is fimbriae and its purpose?
A
short filaments around the cell that allow cell to attach to surfaces
5
Q
what is a bacteria’s cell wall made out of?
A
peptidoglycan; a carbohydrate linked to a protein
6
Q
what is mycoplasma and example?
A
a bacteria that lacks a cell wall, making it resistant to antibiotics
ex. mycoplasma pneumonia cannot be cured with penicillin like most infections
7
Q
function of flagella
A
filament that allows cell to move
8
Q
what does atrichous mean?
A
bacteria with no flagella
9
Q
what does monotrichous mean?
A
bacteria with one flagella
10
Q
what does amphitrichous mean?
A
two flagella; one on opposite sides of the cell
11
Q
what does lophotrichous mean?
A
multiple flagella on one side of cell
12
Q
what does peritrichous mean?
A
flagella all around the perimeter of the cell
13
Q
what do antibiotics stop?
A
the synthesis of peptidoglycan (cell wall)
14
Q
what is conjugation, and what occurs?
A
genetic recombination; where resistance plasmids are shared between bacteria
- mediated by the action of the pilus
15
Q
about how many ribosomes are present in a bacterial cell?
A
20,000
16
Q
list capsule characteristics
A
- only in some bacteria
- an extra layer above the cell wall
- made of carbohydrate
- hard to swallow by macrophages
17
Q
endospores characteristics
A
- some bacteria can produce endospores
- bacteria transform themselves into hard structures that make them resistant to temperatures and chemicals
- contain a lot of calcium and dipicolinic acid
18
Q
axial filaments
A
flagella inside the cell
- allows cells to move and jerk like a caterpillar
ex. syphillis
19
Q
all filaments are made up of ______
A
protein
20
Q
what is the cell envelope of a bacteria composed of?
A
- cell membrane
- cell wall
- glycocalyx
21
Q
glycocalyx characteristics
A
- present in some bacteria
- contains slime layer and capsule
22
Q
capsule characteristics and benefits
A
- an extra hard layer of a carbohydrate
- thick and gummy and difficult to remove
- stuck to the surface
- a combination of polysaccharides and proteins
- protects from phagocytes and macrophages
- makes it difficult for antibiotics to penetrate
23
Q
slime layer characteristics and functions
A
- biofilm
- an extra soft layer of a carbohydrate
- loose structure that is sticky
- serves as a protection from dehydration or losing nutrients
- allows bacteria to be sticky
24
Q
gram-negative characteristics
A
- thin cell wall
- stains red/pink
- extensive periplasmic space
- less permeable to molecules
- very thin layer of peptidoglycan with two cell membranes
- has lipopolysaccharide (LPS); are endotoxins that have the ability to cause infection
25
gram-positive characteristics
- thick cell wall
- stains blue/purple
- narrow periplasmic space
- more permeable to molecules
26
why are some gram-positive bacteria difficult to stain
they may have an extra layer of mycolic acid (lipid)
27
what is bacillus anthracis?
a spore-producing bacteria that produces anthrax and is used by bioterrorists
28
clostridium
- bacteria from the soil
- anaerobic
- spore producing
- can cause botulinum (food poisoning)
- can cause tetanus
29
listeria monocytogenes
- causes listeria
30
what is the most common cause of listeria?
unpasteurized dairy products
31
what does Propionibacterium produce?
- acne
- propionic acid
32
uses of Propionibacterium
- cheese industry; propionic acid give swizz cheese its flavor
33
streptococcus variants
- group A strep: flesh-eating bacteria
- strep throat: bacteria that affect the throat
34
what does Enterococcus cause
diarrhea
35
Staphylococcus characteristics
- food contaminant
- can affect skin, bones, brain, etc.
- mostly found in hospitals
- produces nosocomial infections
36
what are nosocomial infections
infections acquired in hospitals
37
Gram-positive bacteria genera examples
1. Bacillus anthrasis
2. Clostridium
3. Listeria monocytogenes
4. Propionibacterium
5. Streptococcus
6. Enterococcus
7. Staphylococcus
38
gram-negative bacteria genera examples
1. Bacteroides
2. Pseudomonas
3. Escherichia Coli
4. Salmonella
5. Shigella
6. Yersinia
7. Syphilis
8. Vibrio
9. Campylobacter
10. Helicobacter
11. chlamydia
12. Neisseria
39
what is lipopolysaccharide (LPS) and what does it do
- an endotoxin present in gram-negative bacteria
- molecules secreted that allow for the cause of infection
40
Bacteroides
the most abundant bacteria in the human intestine; Bacteroides fragilis
41
Pseudomonas
- found in the soil
- can metabolize any type of compound (even soap)
42
What gram negative bacteria can be useful in the case of an oil spill and why?
pseudomonas because it can eat anything
43
Escherichia Coli
- found in intestines and causes diarrhea
44
salmonella
- found in intestines
- food contaminant
- can kill people
45
shigella
- has a Shiga toxin that can cause severe intestinal disease
46
yersinia
- yersinia pestis: used to kill many and was spread through fleas
- would kill 80% of population when reached a town
- caused what is known as the Black Plague
- now a simple genus that can be easily controlled with antibiotics
47
neisseria
- produces STDs such as gonorrhea
48
gonorrhea symptoms
- produces pus in the urethra and can spread to fallopian tubes
- men can become infertile as well
49
syphilis
- spiral bacteria
- has internal flagella
- causes STD syphillis
50
vibrio
- vibrio cholera disease
>>>> causes watery diarrhea, causing dehydration
- Vibrio vulnificus
>>>> can contaminate oysters
51
Campylobacter
- involved in food contamination
52
helicobacter
H. pylori: grows in the stomach
- causes stomach ulcers
- can be controlled with antibiotics
53
chlamydia
- causes STD
- very small bacteria
54
which are the only bacteria that grow intracellularly like viruses and are considered intracellular parasites?
chlamydia and rickettsia
55
which gram negative bacteria is difficult to stain?
1. rickettsia
2. chlamydia
3. legionella
4. leptospira
5. coxiella
6. treponema
7. bartonella
56
mycoplasma pneumonia characteristics
- has no cell wall
- pleomorphic
- antibiotics will not work because there is no cell wall
57
cell membrane characteristics
- made of phospholipids
- substances can only pass with the use of protein channels
58
what is the cytoplasm?
- matrix that supports all structures found in a cell
59
ribosomes is a place for _______
protein synthesis
60
chromosomes is another name for _______
DNA
61
DNA of bacteria characteristics
- very compacted
- circular
- 1000x longer than actual bacteria
- ~ 4,000 genes
62
examples of bacteria that produce endospores
clostridium and bacillus
63
why does a bacteria turn itself to an endospore and what happens when they do?
when they feel threatened by the environment and they become inactive until the environment is suitable
64
how do spores of bacillus anthrasis become toxic?
Once people inhale them, they enter the lungs, which is a suitable environment. They revert back to bacteria and produce the disease anthrax.
65
what shape is coccus bacteria?
round
66
what shape is bacillus?
rods
67
what shape is vibrio
curved
68
what shape is spirillum
spiral
69
what shape is spirochete
corkscrew; very spiraled
70
pleomorphic
bacteria that can take up any shape because of the lack of cell wall
71
diplococci definition and example
two cocci joined together
ex. Neisseria; bacteria causing gonorrhea
72
tetrads definition and example
cocci in groups of four
ex. micrococcus; bacteria on the skin
73
irregular clusters definition and example
cocci resembling grapes
ex. staphylococcus; resistant to many antibiotics
74
streptococci
chain of cocci
75
sarcina
- groups of cocci in multiples of 8
76
diplobacilli
two rods of bacilli
77
streptobacilli
chain of rods
78
what are the most common shapes of bacilli
single, diplo, and strepto
79
what taxonomic system is used for prokaryote classification
Bergey's Manual of Determinative Bacteriology
80
what are the volumes found in Bergey's Manual of Determinative Bacteriology
I. Domain Bacteria/Archae
II. Proteobacteria (gram-negative)
III. Low G+C bases; gram positive bacteria
IV. High G+C bases; gram positive bacteria
V. Gram negative
81
Bergey's Manual of Determinative Bacteriology classification is based on:
the cell wall in detail
82
what is medical classification based on?
the structure of the cell wall
83
In medical classification, a gram-positive/ thick cell wall is considered:
firmicutes
- they are very FIRM because of thick cell wall
84
In medical classification, a gram-negative/ thin cell wall/ pink stain is considered:
gracilicutes
85
In medical classification, a bacteria with no cell wall is considered:
tenericutes
86
In medical classification, a bacteria with an unusual composition of cell wall is considered:
mendosicutes
87
what disease does rickettsia cause and how is it transmitted?
Rocky Mountain Fever; transmitted by ticks, lice, and fleas
88
what is a unique feature bacterias rickettsia and chlamydia share?
they have no metabolism, so they cannot live outside of a host
89
what diseases does chlamydia cause and how are they transmitted?
Chlamydiosis (STD); transmitted through sexual contact
Trachoma: disease of the eyes
90
photosynthetic bacteria definiton
- bacteria that have different pigments similar to chlorophyll that allow them to perform photosynthesis
- considered autotrophs
91
cyanobacteria characteristics
- aka blue-green bacteria
- gram negative
- photosynthetic
92
where can cyanobacteria be found?
in aquatic environments
93
what allows cyanobacteria to float?
gas inclusions
94
why are cyanobacteria considered pests?
they compete for oxygen with fish, depleting the fish's nutrients
95
green and purple sulfur bacteria characteristics
- found in sulfur springs, deep in lakes, swamps, fresh water
- bacteriochlorophyll: pigments allow them to photosynthesize
- has structures that can store sulfur
96
Archaea compared to bacteria
- exceptional structure of physiology
- chemically different
97
TRUE OR FALSE: Archaea are more closely related to eukaryotes than bacteria.
TRUE
98
What features in archaea support the idea that they are more closely related to eukaryotes than bacteria?
- the introns and histones found in its DNA (bacteria do not have these)
- 80S ribosome (bacteria has 70S ribosomes)
- mRNA has a cap and tail (5' - 3')
99
what are introns?
"junk DNA"
- DNA that does not code for anything
100
methanogens definiton
- archaea that produce methane
- contribute to greenhouse effect
101
halophiles definition and example of where to find them
- archaea that can grow in an environment up to 36% NaCl
ex. the Dead Sea
102
thermophiles definition and example of environment
- archaea that can withstand temperatures up to 120 C
- live near volcanoes
103
what gas is able to kill all endospores, but area needs to be cleared as it is a carcinogen?
ethylene oxide
