Lecture 6 Flashcards
(100 cards)
1
Q
How small are the diameter of prokaryotes
A
~1-5μm
2
Q
How small are the diameter of eukaryotes
A
10-100μm
3
Q
Pathogen
A
disease causing agents
4
Q
Studies of rRNA sequences of prokaryotes in the 1970s revealed that..
A
many prokaryotes first classified s bacteria were actually more similar to eukaryotes
5
Q
Archaea and eukaryotes evolved from ..
A
a common ancestor
6
Q
Differences between bacteria and archaea include ..
A
- bacteria have peptidoglycan and archaea do not
- archaea have a number of different RNA polymerase bacteria have only one
7
Q
What does it mean that bacteria have peptidoglycan and archaea don’t
A
bacteria respond to cell wall active antibiotics archaea do not
8
Q
3 different shapes prokaryotes come in
A
- cocci
- bacilli
- spiral
9
Q
Cocci
A
spherical shape hurter characterized by arrangement
10
Q
2 examples of cocci
A
- staphylococci: grape life clusters of circles
- streptococci: chains of circles
11
Q
Bacilli
A
rod shape- usually a single rod
12
Q
2 examples of bacilli
A
- diplobacilli: two rods together
- streptobacilli: rods arranged in a chain
13
Q
Spiral
A
helical shape
14
Q
2 examples of spiral
A
- spirilla: short and rigid helical structure
- spirochete: long, more flexible helical structure
15
Q
Bacterial cell wall composed of
A
sugar called peptidoglycan
16
Q
Bacterial cell wall maintains ..
and provides…
A
- cell shape
- physical protection and prevents cell from bursting in hypotonic environments
17
Q
Hypertonic environments cause bacteria to..
A
shrivel, inhibiting reproduction
18
Q
2 main types of bacterial cell walls
A
- gram positive
- gram negative
19
Q
Gram positive
A
thick layer of peptidoglycan
20
Q
Gram negative
A
thin layer of peptidoglycan w outer membrane
21
Q
These two types stain differently during a gram stain-an identification tool used in the microbio lab and the colours are..
A
- gram positive stain purple
- gram negative stain pink
22
Q
Capsule
A
sticky layer of polysaccharide or protein covering the cell wall, found in many but not all prokaryotes, shield the microorganism from host defences
23
Q
Capsule allows the bacterium to adhere to..
A
- other organisms
- medical devices such as catheters
- other surfaces
24
Q
Pili look like..
A
hair like appendage
25
Pili allows bacterium to..
adhere to one another or to their substrate
26
Pili allows adherence to.
rocks in streams or the lining of the human intestine
27
Flagella
structure enables bacterial motility, not present in all bacteria
28
Flagellated bacteria may have ..
one flagella, two flagella, or many scattered all over the surface
29
Flawless allows the bacteria to move ..
towards chemical and light stimuli called attractants and away from repellent stimuli
30
Specialized pili called..
sex pili allow bacteria to stick to one another and transfer DNA
31
Conjugation
transfer of DNA from bacteria to bacteria
32
Bacterial replication occurs very quickly by a process called ..
binary fission
33
Time it takes for species to complete binary fission ..
some species can reproduce in as little as 20 minutes, other take 1-3 hours
34
Bacterial growth is limited because..
- nutrients become exhausted, metabolic waste builds up
- competition from other organisms
- antibiotics are present in certain environments
35
Endospores structures ONLY formed by
gram positive organisms
36
Endospores
used to withstand harsh conditions, outer cell will disintegrate and the inner cell will remain.
37
Endospore has a ___ outer coat
thick
38
Endospores will ..
dehydrate and become dormant until conditions become favourable, then when favourable it will absorb water and resume growth
39
Respiratory membrane is for
cellular respiration
40
Thylakoid membrane is for.. and used in ..
- photosynthesis
| - cyanobacteria
41
Prokaryotes have ____ as much DNA as eukaryote
1/1000
42
Cells may have plasmids which are..
smaller pieces of DNA acquired from other bacteria which contain specialized genes
43
Prokaryotes have smaller ribosomes which are __
70s
44
Prokaryotes require 2 main metabolic resources
- a source of energy
| - a source of carbon
45
2 sources of energy for metabolic resources
- light (phototroph)
| - chemical (chemotroph)
46
2 sources of carbon for metabolic resources
- autotrophs
| - heterotrophs
47
How prokaryotes use source of carbon metabolic resources
make their own carbon compounds while other require pre formed carbon
48
Autotrophs
use an inorganic source of carbon dioxide to form organic carbon (glucose) processed called photosynthesis
49
Heterotrophs
obtain their carbo from organic compounds such as glucose
50
Bacteria may love in surface-coating colonies called..
biofilms
51
Biofilms may consist of a ..
single species of bacteria or many diff species
52
Biofilms form when..
bacterial cells secrete signalling molecules which recruit nearby cells
53
When the biofilm colony reaches a sufficient size the bacterial cells of the colony begin producing ...
proteins that cause them to stick to a particular surface and to each other
54
There are channels within the biofilm which ..
all nutrients and wastes to enter and leave
55
In humans biofilms allow bacteria to adhere to..
teeth causing causing dental cavities
56
Biofilms also form on..
catheters and other medical devices causing serious problems
57
Biofilms are beneficial when used in..
water sewage treatment facilities
58
Archaea
have unusual proteins and other molecules adaptions that allow them to survive and reproduce where few other organisms can
59
3 main groups of archaea
- extreme halophiles
- extreme thermophiles
- methanogens
60
Extreme halophiles
these archaea live in waters with high salt concentrations . 15-20 % salt concentration
61
Extreme thermophiles
archaea that thrive in water of very high temperatures, some live near deep ocean vents where temps exceed 100 C
62
Methanogens
archaea that live anaerobic environments, produce methane as a waste product
63
Methanogens can be found in ..
anaerobic mud at the bottoms of lakes and swamps
64
Where can methanogens be found in the human body
in the intestinal tract of humans
65
Even tho archaea are dubbed extremophile they are also...
abundant in moderate environments as well
66
Domain bacteria is divided into 9 groups
- proteobacteria
- chlamydias
- spirochetes
- gram positive
- cyanobacteria
67
Proteobacteria composed of..
gram bacteria negative organisms
68
Proteobacteria contains 5 subgroups, 3 are ..
- alpha
- gamma
- delta
69
Alpha
including rhizobium species which live in plant roots and fix nitrogen from the atmosphere for the plant
70
Gamma
including salmonella, E. coli, and photosynthetic sulfur bacteria that oxidize
71
Delta
includes slime secreting myxobacteria which form elaborate colonies and Bdellovibrio which attack other bacteria
72
Chlamydias live inside of..
eukaryotic cells
73
Chalmydia trachomatic
causes blindness in developing areas and is responsible for the most prevalent STI: chlamydia
74
Spirochetes
helical shape, well known pathogens
75
Gram positive group of bacteria are.. and rivals the ..
- very diverse
| - proteobacteria
76
Gram positive group includes..
staphylococcus spp. and streptococcus spp.
77
Streptomycin within the gram positive group are used by..
pharmaceutical companies to produce antibiotics such as streptomycin
78
Cyanobacteria
prokaryotes that function to generate oxygen via plant like photosynthesis
79
Stromatolite fossils were generated by ancient
cyanobacteria
80
Cyanobacteria are thought to be responsible for..
generating the oxygen that make the atmosphere aerobic
81
Modern day cyanobacteria provide ..
a large amount of food for freshwater and marine ecosystems
82
Bacteria that cause illness usually do so by producing toxins, what are the 2 classes of bacterial toxins
- exotoxins
| - endotoxins
83
Exotoxin
these are secreted by the bacterial cell into the surrounding environment
84
Examples of exotoxins
tetanus toxin and botulinum
85
Staphylococcus is an ____ producer
exotoxin
86
Endotoxin
components of the outer membrane of gram negative bacteria. only harmful when they are released which occurs when the cell dies
87
Example of endotoxin
salmonella
88
Endotoxins always cause the same symptoms
- fever
- aches
- sometimes a dangerous drop in BP (septic shock)
89
Reasons bacterial disease have been drastically decreased during the last century
- improved sanitation and hygiene
- water treatment and sewage systems
- education
- vaccine and antibiotic development, discovery and use
90
What bacteria used in mail attacks of the US
Bacillus anthracis
91
Bacillus anthracis
forms hardy endospores, spores are commonly found in soil
92
2 ways bacillus anthracis can contact you
- through skin cuts but is easy to treat
| - inhalation of the spores is deadly
93
Inhalation form of the spores
.... continue slide when teacher explains
94
Bacillus anthracis can be treated with..
antibiotic but the its useless if the toxin is already in the blood
95
Yersinia pestis is..
the bacterium that causes the plague
96
Clostridium botulinum produces which toxin.. and is one of the most..
- botulinum
| - potent toxins known
97
Biomediation
use of organisms to remove pollutants from the soil, water, or air
98
Solid sewage is treated with..
anaerobic bacteria which breaks down the organic matter so that it may be used as fertilizer
99
Liquid waste is ..
passed along biofilms of bacteria and archaea adhered to rock, the organisms of the biofilm digest much of the organic matter
100
Bacteria are also important in the cleaning off..
oil spills and old mining sites
