micro test 3 Flashcards
(123 cards)
1
Q
a generation is a
A
doubling of the population
2
Q
the – creates 2 cellular compartments during binary fission
A
septum
3
Q
– have the same activity as lysozyme and break down glycosidic bonds in peptidoglycan at the point of new synthesis
A
autolysins
4
Q
– is highly hydrophobic and shuttles precursors across the membrane.
A
bactoprenol
5
Q
– interacts with assembly proteins to catalyze incorporation of new sugars (glycosidic bonds)
A
bactoprenol
6
Q
peptidoglycan transpeptidase catalyzes
A
cross linking
7
Q
penicillin targets –
A
peptidoglycan transpeptidase
8
Q
a long doubling time means a – growth rate
A
slow
9
Q
every time there is a 1000 fold increase in cell populations, there has been around — generations
A
10
10
Q
exponential growth equation
A
N=N0 * 2^n
11
Q
generation time equation
A
g= t/n
12
Q
in the exponential growth equation, what does N mean
A
number of cells at a given time
13
Q
in the exponential growth equation, what does N0 mean
A
starting number of cells
14
Q
in the exponential growth equation, what does n mean
A
the number of generations
15
Q
in the generation time equation, what does g mean
A
generation time
16
Q
in the generation time equation, what does t mean
A
time
17
Q
in the generation time equation, what does n mean
A
number of generations
18
Q
what equation can be used to determine generation time from the slope of a line
A
g= log2/ slope
19
Q
how can division rate be calculated from generation time
A
1/g= division rate
20
Q
what is the log of 10^8
A
8
21
Q
what is the log of 100
A
2
22
Q
what is 1/log(2)
A
3.3
23
Q
? = 3.3(logN - logN0)
A
n
24
Q
– is the phase where the bacteria is not yet in the exponential phase
A
lag phase
25
-- is the phase with exponential growth
exponential
26
-- is the phase where the bacteria have run out of nutrients and can no longer grow, but are still viable
stationary phase
27
-- phase is when the bacteria can no longer grow and are not viable
death
28
chemostats can control bacterial growth rate through control of nutrient ---
supply
29
chemostats can control bacterial cell density through control of nutrient ---
concentration
30
if the -- is too fast, washout will occur
dilution rate
31
a -- supplies a constant supply of cells in a stable, unvarying condition
chemostat
32
do you have to use pure cultures in a chemostat
no
33
total cell counts and viable cell counts are both -- measurements
direct
34
turbidimetric measurements are -- measurements
indirect
35
direct cell counts are hard with -- cells
motile
36
what is the great plate count anamoly
the number of viable cells is lower than it should be
37
why use CFU instead of cell in pour plates
not every cell gives rise to a colony
38
temperature at which enzymatic reactions occur at maximal possible rate
optimum
39
temperature at which membrane gells; transport processes are so slow that growth cannot occur
minimum
40
temperature at which proteins denature; collapse of the cytoplasmic membrane; thermal lysis
maximum
41
organisms that prefer temperatures around 4 degrees C
psychrophile
42
organisms that prefer temperatures around 39 degrees C
mesophile
43
organisms that prefer temperatures around 60 degrees C
thermophile
44
organisms that prefer temperatures around 88 degrees C
hyperthermophile
45
organisms that can grow at <5 degrees C but prefer temperatures around 20-40 degrees C
psychrotolerant
46
-- organisms tend to have more alpha helices and less beta sheets
psychrophilic
47
-- organisms tend to have more polar side chains and fewer weak interactions
psychrophilic
48
--- organisms tend to have more unsaturated lipids in the membrane
psychrophilic
49
cryoprotective molecules reduce dehydration and -- formation
ice crystal
50
-- proteins tend to be less heat tolerant than thermophilic proteins
photosynthetic
51
prokaryotes have -- temperature growth abilities than eukaryotes
higher
52
the -- branch contains the most thermophilic and hyperthermophilic species
archaeal
53
non-phototrophs can exceed phototrophs in --- growth abilities
thermophilic
54
--- organisms tend to have amino acid substitutions at key places to increase stability
thermophilic
54
-- organisms tend to have more ionic bonds and denser hydrophobic protein cores
thermophilic
54
some --- organisms have phospholipid monolayers (archaea)
thermophilic
54
--- organisms tend to have high saturation rates of fatty acids in their membranes
thermophilic
55
PCR uses Taq polymerase because it is from a --- organism
thermophilic
56
--- grow at low pH
acidophiles
57
--- grows at high pH
alkaliphiles
58
-- are necessary inside the cell to draw in water and to maintain a positive water balance
solutes
59
-- require O2 for growth; O2 is the final e- acceptor in their respiration
obligate aerobes
60
-- do not need or use O2. O2 is toxic to these organisms. these organisms ferment or respire without O2
obligate anaerobes
61
-- organisms that can switch between aeobic and anaerobic respiration
facultative anaerobes
62
--- require some oxygen yet atmospheric levels are toxic
microaerophiles
63
--- bacteria with an exclusively fermentative type of metabolism but they are insensitive to O2
aerotolerant anaerobes
64
O2 + e- =
superoxide, toxic
65
O2- + e- =
H2O2, toxic
66
H2O2 + e- =
OH + radical
67
OH (+ radical) + e- =
H2O
68
what enzyme: H2O2 + H2O2 -> 2 H2O + O2
catalase
69
what enzyme: H2O2 + NADH + H+ -> 2 H2O + NAD+
peroxidase
70
O2- + O2- + 2H+ -> H2O2 + O2
superoxide dismutase
71
O2- + 2H+ + cyt c(reduced) -> H2O2 + cyt c(oxidized)
superoxide reductase
72
--- is the positive reaction from the catalase test
bubbling
73
-- is the most widely used method of sterilization
heat
74
--- must eliminate the most heat resistant organisms, usually bacterial endospores
sterilization
75
--- does not sterilize liquids but reduces microbial load (prevents spoilage)
pastuerization
76
--- amount of time at a temperature that it takes cells to decrease in viability by 10%
decimal reduction time
77
-- use steam to sterilize things
autoclave
78
is pastuerization a sterilization technique
no
79
-- radiation causes surface decontamination
UV
80
-- radiation generates highly reactive ions
ionizing
81
lethal dose of ionizing radiation for humans (grays)
10
82
-- filters filter air and have a fibrous nature
depth
83
-- filters have ~80% open pores and traps filtrate on the surface; common for heat sensitive liquid filtration
standard membrane
84
--- filters are formed by etching polycarbonate film after nuclear radiation
nucleopore membrane
85
the amount of radiation to be applied to reduce the viable cell numbers by a factor of 10^12
lethal dose
86
-- agents kill bacteria
bactericidal
87
-- agents stop bacteria from growing
bacteriostatic
88
-- agents kill bacteria and lyses them open
bacteriolytic
89
gaseous infusion of chemicals; no living tissue left
sterilant
90
kill most organisms (not endospores); cationic detergents
disinfectants
91
reduce microbial populations to "safe" levels; chlorine and iodine compounds
sanitizer
92
safe for application to living tissue; alcohol solutions
antiseptics
93
what is the folic acid analog
sulfanilamide
94
naturally occurring substances with antibacterial properties
antibiotics
95
--- can make bacteria resistant to penicillin
beta-lactamase
96
attacks DNA gyrase
quinolones; ciprofloxacin
97
attacks RNA pol
rifampin
98
attacks cell wall synthesis
penicillins
99
attacks 50S protein synthesis
erythromycin
100
attacks 30S protein synthesis
tetracyclines
101
the range of species for which an antibiotic is effective
antibiotic spectrum
102
effect of a combination of antibiotics is greater than the sum of either antibiotic separately
antibiotic synergism
103
interference of efficacy of one antibiotic when coupled with a second antibiotic
antibiotic antagonism
104
resistance: if the target changes so the antimicrobial cannot interact
target modification
105
resistance: if the cell can pump out the antibiotic
antibiotic efflux
106
resistance: if the antibiotics are broken down or modified so they cannot work
antibiotic modification
107
resistance: cells will get a nutrient that they need that they can no longer make
resistant pathways
108
resistance: antibiotics cannot enter the cell
antibiotic impermeability
109
when something is toxic to only a certain type of cells (non-human)
selective toxicity
110
-- are genetic elements with an obligate intracellular replication cycle
viruses
111
--- are the extracellular form which include the nucleic acid and normally a protein coat and possibly an outer envelope
virion
112
classes of viruses:
ss DNA, ds DNA, ss RNA, ds RNA, ss RNA -> DNA, ds DNA -> RNA
113
in viruses, the nucleic acid is surrounded by a protein coat called the ---
capsid
114
capsids are made up of one or more protein subunits called
capsomers
115
enveloped virus membranes are derived from ---
host cell membrane
116
can viruses have enzymatic activity away from the host cell
no
117
viruses of eukaryotes can be grown in --
tissue culture
118
-- are typically grown as plaques on lawns of cells
bacteriophage
119
-- refers to the fact that normally only a small portion of the virions result in plaques
plating efficiency
120
