Microbio > Lecture Exam III > Flashcards

Lecture Exam III Flashcards

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1
Q

What are bacterial cells composed of?

A

70% water
proteins

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2
Q

Macroelements

A

96% of cell is composed of 10 key elements

C,H,O, Ph, Su, N in gram qty

K, Ca, Mg, Fe in milligram qty

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3
Q

Why is Potassium important to microbial metabolism?

A

needed for protein synthesis and membrane function

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4
Q

Why is Calcium important to microbial metabolism?

A

needed for cell wall and endospore stabilizer to help survive harsh environments
helps bone structure and muscle contraction in humans

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5
Q

Why is Magnesium important to microbial metabolism?

A

membrane and ribosome stabilizer
protein synthesis

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6
Q

Why is Iron important to microbial metabolism?

A

part of the ETC needed for ATP production

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7
Q

Prime Minister

A

Potassium and Magnesium

needed in protein synthesis

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8
Q

Trace elements (4%)

A

if it sounds like a metal it’s probably a trace element
minerals- manganese, zinc, cobalt, nickel, copper

usually part of enzymes and cofactors

help reaction catalysis (speeds up to 1000x)
helps maintain protein structure

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9
Q

E. coli only needs a few compounds from the environment

what does this mean?

A

glucose, trace elements, Water, 6+

has at least 607 really good enzymes!
just a few used to metabolize around 5000 compounds

some enzymes can attach to multiple at once and serve many fxns

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10
Q

organic nutrients

A

C or H (organic must have BOTH)
all organic compounds must have a C backbone

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11
Q

environmental factors that influence microbes (metabolic enzymes)

A

enzymes drive rxns, so if no active enzymes, then cell dies

temperature- slows bacterial growth
pH
O2
Osmotic pressure
radiation
barometric pressure
ecological associations

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12
Q

3 cardinal temperatures

A

minimum temperature- min that permits microbe growth and metabolism; barely dividing, cold temp keeps enzyme from interacting w substrate

maximum temperature- highest temp that allows growth and metabolism before denaturation

optimum temperature- promotes fastest rate of growth and metabolism; based on enviromental factors

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13
Q

poikilothermic

A

ambient Tº

room temp- 25ºC
body temp- 37º
Fridge- 4ºC
Freezer- 0ºC

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14
Q

Temperature adaptation groups
Psychrophiles

A

cold loving
-10º to 20ºC (opt. 10-13ºC)
not human pathogens because temp is too high, can grow in fridge

lipids in cell membrane is highly unsaturated (double bonds)

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15
Q

Temperature adaptation groups
Psyhcrotolerant

A

4-35ºC (opt. 15-30ºC) grows slowly in cold temp

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16
Q

Temperature adaptation groups
Mesophiles

A

10-45ºC (opt. is 20-40ºC)
human pathogens and normal flora, environment microbes

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17
Q

Temperature adaptation groups
Thermophiles

A

45-80ºC (opt. 67-72º)
compost pile, hot water heater

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18
Q

Temperature adaptation groups
Extreme Thermophiles
Archae

A

70º+
hot springs, deep ocean vents

Archae- unique enzymes, high C+G DNA, no peptidoglycan, lipids in cell membrane are highly saturated (no double bonds)–> more resistant to heat

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19
Q

pH (levels and importance)

A

measures hydrogen activity
defines level of acidity or alkalinity (0-14)

pure water- 7 (neutral)
our body is 7.2-7.4 (not in stomach)

opt is 6-8
important due to poss damage to proteins and CM

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20
Q

pH (effects)

A

related to concentration of teichoic acid in the medium to protect cell walls

changes can lead to enzyme/protein denaturing; can interfere w pumping ions at CM

bacteria produces large qty of acids as they metabolize and grow= high level of acid concentration= toxic

can become toxic in closed system

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21
Q

pH scale

A

most acidic- high H+
our bodies can handle acids well, but basic solns can damage esophagus

(A->B)
1-battery acid
2-3: stomach acid, coke, vinegar
3-4: vinegar, adult fish die
4-5: fish reproduction affected
5-6: rain water
7-8: pure water/blood, supports freshwater organisms
8-9: baking soda
12-13: ammonia

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22
Q

effects of pH

A

acidophiles- extreme acidic conditions (0-5.5)
neutrophiles- most pathogens here (6-8), fungi grows at lower pHs than bacteria
alkalophiles- between 8.5-12

**using a description give names
ie: organism in fridge on acidic fruit - psychrotrophic acidophile

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23
Q

Helicobacter pylori (pH effects)

A

high motility rate
found in stomach (pH- 2.5)
causes ulcers, gastric/esophageal cancer
NOT ACID TOLERANT

produces toxins causes inflammation and damage
stress and environmental factors make dx worse

protects itself by growing in a protective mucus layer

breaks down urea= produces ammonia= neutralizes microenvironment

treated w abx

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24
Q

Gas requirements

A

O2 has a single electron on outer orbit, steals e- from other compound and oxidizes

as O2 is used it can become toxic products
most cells develop protective enzymes that neutralize toxic O2 products (catalase- superoxide dismutase)

if a microbe can’t deal w toxic O2, it lacks a protective enzyme so it lives in an anaerobic conditions

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25
Aerobe- uses oxygen and can detoxify it (has protective enzymes) obligate, facultative, microaerophillic
uses O2 and can detoxify it obligate- can't grown w/o oxygen facultative- uses oxygen but can grow w/o it [can grow in both, but prefers O2; more ATP produced: 36 v 2) microaerophillic- only needs a small amt of O2, grows best at 5% O2
26
anaerobe- does not use oxygen lacks protective enzymes obligate anaerobe aerotolerant anaerobe
obligate- lacks enzymes to detoxify; O2 is toxic to it (obligated to not tolerate O2) aerotolerant- grows in O2 but does not use it, uses metal ions as a protective mechanism
27
what does an obligate aerobe look like on a bacterial growth tube?
growth happens where O2 concentration has diffused into medium all the growth happens at the top of medium
28
what does an facultative anaerobe look like on a bacterial growth tube?
aerobic and anaerobic growth, more growth w O2 present heavier at the top (preferred bc there is more ATP present) heavy concentration at top, has growth dispersed throughout the entire tube
29
what does an obligate anaerobe look like on a bacterial growth tube?
only happens where there is no oxygen all of growth towards the bottom of the tube
30
what does an aerotolerant anaerobe look like on a bacterial growth tube?
only anaerobic growth but continues w O2 presence growth happens evenly, O2 unaffected even growth throughout
31
what does an microaerophiles look like on a bacterial growth tube?
low oxygen requirement only aerobic growth in small concentration high concentration of bacterial growth at halfway point
32
osmotic pressure availability
availability of water in environment varies and depends on actual amt of water solute of water most microbes exist under hypotonic or isotonic conditions
33
halophiles require...
high concentration of salt
34
osmotolerant
does not req a high concentration of solutes but can tolerate them if needed seen on skin; salt left behind when sweating (gram +)
35
osmotic pressure
water activity (Aw) measures water available for use Aw lowers when solutes added (inc solute, inc osmotic pressure, dec., Aw) dec Aw, dec enzyme fxn, dec metabolism, death of cell
36
Water activity and osmotic pressure
inversely related Aw of pure water is 1.00 most organisms req at least 0.90-1.00 for metabolic activity
37
salts and sugars do what to Wa
decreases used as a food preservative
38
Radiation - is there anything that can repair damage? -what survives ionizing radiation (sterilization)
UV lights mutates DNA and can even kill organisms sometimes enzyme systems can repair damage endospores
39
bacillus stearothermophilus endospores
purple sugar broth in ampule and spores on a piece of filter paper autoclave then crush to release broth and coat paper w spores if yellow--> spores germinated, acid produced, spores not killed was not sterilized
40
sterilization what wavelengths?
short ones high Eº generates ions that destroy DNA
41
Hydrostatic pressure autoclave
pressure exerted by water column from the weight of the column w each 10m of water depth equivalent to 1 atm autoclave- heat and pressure human pathogens can be autoclaved
42
hydrostat pressure .200 atm
inactivate enzymes needed for ATP disrupts cell membrane and transport systems
43
hydrostatic pressure in deep ocean
can reach >1000 atm bacteria can survive and adapt barophiles rupture when exposed to normal atmospheric pressure, bc it needs pressure to keep its 3D shape
44
symbiosis 1. mutualism 2. commensalism 3. parasatism
organisms w relationships (one dependent on the other) 1.obligatory, both benefit 2. one benefits, the other unaffected 3. parasite dependent and benefits, other is harmed
45
mutualism ex: lichens
association b/w fungus and microbe (algae or cyanobacteria) the fungus protects bacteria from excess light and UV fungus gets the organic carbon from synthetic organism -protects UV light -supplies water and minerals -structure support lichens resistant to extreme temps and dessication, sensitive to air pollution
46
BSL 1,2,3,4 which is our lab?
1: no precautions 2: lab coats, gloves, eye protection - microbes can be associated w human disease 3: biosafety cabinets prevent airborne transmission - microbes cause human disease when encountered but are treatable 4: sealed, neg pressure- deadly organisms that have no current treatment
47
metabolism -catabolic -anabolic know if Eº is used or released
anabolic: building process, 2 small subs make 1 big molecule (bonds made) Eº used [anabolic steroids] catabolic: breakdown process, 1 molecule breaks down into 2 substrates Eº released [cats break stuff]
48
enzyme structure simple conjugated cofactors
simple- only protein conjugated- protein + nonprotein molecule (cofactor) cofactors are either organic (coenzynes) or inorganic elements like metal ions or vitamins enzymes speed up rxns up to 1000x faster
49
enzyme-substrate complex {when cofactor is inorganic} function
for reaction to take place these must unite now rxn will happen on the substrate with the help of the cofactor; releasing a product fxn: "better fit" bw enzyme and sub shape of active site changes
50
enzyme-substrate complex {coenzyme} function
coenzyme removes the functional group from Sub 1 and adds it to Sub 2 [transient carrier, rates rate of catalysis
51
enzyme sensitivity -extreme Tº`
when subject to changes, it can unforld/degrade/ denature its shape low temps does not allow catalysis high temps, some chemicals, and extreme pH's can denature enzymes non functional enzymes block reactions leads to cell death
52
microbial growth at two levels
cellular level increases in cell size, increases population divides thru binary fission parent get bigger, DNA is duplicated, forms a crosswall dividing into 2 daughter cells
53
DNA replication synthesis
new DNA synthesis starts before the prev round is done so when it divides, a full and part of a second chromie is complete
54
bacteria average generation time (time needed for complete binary fission cycle) Nf=(Ni)2n
20-60 mins
55
growth curve in a closed system lag,log,stationary, death
nutrients and space are limited and grows over a few hrs to days lag- intense prep to grow log- logarithmic exponential growth stationary- equilibrium death- dec at a log. rate
56
lag phase
no immediate increase in cell # cells can be old/depleted of enzymes, rirbosomes, nutrients needed to metabolize and grow most of the time bacteria is prepping for division
57
log phase
growing and dividing at fastest rate possible continues as long as cells have good conditions and enough nutrients population is most uniform in chemical and physiological characteristics actively growing cells are susceptible to mishaps gt determined at this phase
58
Stationary phase
eventual growth stops and line becomes horizontal total # of viable microorganisms remain constant rate of cell growth = rate of cell death due to lack of nutrients,space, low pH accumulates acids and waste
59
death phase
detrimental environmental changes decline in # of viable characteristics of death phase limiting factor intensifies loss of nutrients and low pH is now toxic dies off logarithmically
60
growth patterns account for stages in infection log
more infectious/ metabolically active, max rate more infectious at log (beginning) of infection the shorter the Gt the faster it can reach high #s and overwhelm immune system
61
sterilization
kills viable microbes including endospores can only be used on inanimate objects
62
disinfection
physical/chemical process that destroys vegetative pathogens NOT endpospores ex: steam UV
63
antiseptic
prevents infection disinfectants applied directly to exposed body surfaces
64
sepsis
microorgs grow in blood/tissue
65
degerming
removing microbes from an area
66
sanitization
lowering microbe counts on utensils (safe but not microbe free)
67
cide vs static
cide: kills microbes static: inhibits, not kill
68
factors that affect death rate: number of microbes
larger pops means longer time to kill off death is also exponential
69
factors that affect death rate: microbial characteristics
consider the nature of the microbe gram + or gram - prokaryote v eukaryote
70
factors that affect death rate: temperature and other environmental factors
temp inc enhances activity of chemicals local environment -slightly acidic pH -small change in Tº increase in water = higher kinetic energy= chemicals work together
71
factors that affect death rate: concentration of dosage agent
the more concentrated the faster is destroyed except: bleach (10% working soln), alcohol (70% disinfectant vs 95% staining) some H2O so that disinfectant is soluble and alcohol does not evaporate so fast
72
factors that affect death rate: duration of action of agent
the longer the population is exposed to agent the better 70% alcohol- bactericidal leads to evaporation so the time is reduced
73
factors that affect death rate: presence of solvents, organic matter, or inhibitors
dirt blood etc cause physical blockage blood contains enzymes that can degrade or breakdown agent blood has catalase that breaks down H2O2 (hydrogen peroxide)
74
decreasing order of resistance of microorganisms to chemical biocides Perry eats many crusty veggies granted fineas gave them to him
Prions (proteins) Endospores (hard outer capsule) Mycobacteria (gooey cell wall) Cysts of protozoa Vegetative protozoa Gram negative Fungi Virus without envelope Gram positive Virus w lipid envelope
75
antimicrobial drugs
interfere w growth of microbes within host
76
antibiotic
natural product made by one microbe to inhibit or kill another
77
selective toxicity
killing harmful microbes w/o damaging host
78
narrow spectrum
effective on a small range of microbes targets a specific component
79
broad spectrum
big range of activity targets a highly conserved structure
80
transcription -messenger -ribosomal transfer
production of various RNAs from DNA template all form thru trascription but only mRNA translates further into a protein ribosome= rRNA+ protein
81
mRNA
message for protein synthesis info coded in it acts during translation, dictates the sequence of AA for the new protein PROK: each mRNA starts w methionine (AUG) and ends w a stop codon (UAA, UAG, UGA)
82
DNA is read... RNA is read...
3 to 5 5 to 3
83
redundancy in codon
allows protection against mutations in the same AA
84
wobble effect
3rd place on codon allows mutations in DNA that won't directly harm us
84
PROK: all components come together to translate mRNA into...
proteins
84
string of aa turn into
growing polypeptide
85
what does translation convert
nucleotide sequence of mRNA into sequence of aa into a protein
86
in translation all elements needed for protein synthesis are brought together by what?
ribosome
87
how much energy from the bacterial cell goes into protein synthesis?
80-90 the rest is used to put DNA together into a new genome
88
1st tRNA carrying fMET enters at ___ site all other tRNA's enter at ___ sire what bond forms between 1st and 2nd amino acid
P A peptide
89
AUG=
fMET added if AUG shows up somewhere else it is just a regular MET
90
translation steps I Eat Tacos
Initiation: all steps before 1st peptide bond ribosome reads 5 to 3 Elongation: 1st peptide bond to last peptide bone (tRNA can recharge w aa) 50S moves first then 30S ( 1 codon at a time) Termination: reactions after last peptide
91
stop codon are aa added? what does the release factor cause?
no peptide, ribosome, subunits, tRNA release
92
polysome
multiple ribosomes on 1 strand of mRNA PROK: degradation after 5 mins of transcription EUK: T&T are physically separated so it can't happen at the same time
93
antimicrobials that affect bacterial cell walls
penicillin and cephalosporin Beta lactams block peptidoglycan synthesis best for log phase in young cells best w gram + since these do not penetrate outer membrane
94
antimicrobials that disrupt cell membrane fxn
polymyxins cell w damaged membrane dies from lysis interact w phospholipid and leaks in gram negative UTI (E coli)
95
antimicrobials that inhibit NA synthesis
Rifampin (attacks RNA polymerase) blocks synthesis of nucleotide or stop transcription
96
antimicrobials that inhibit protein synthesis block translation
not a good idea long term bc of eukaryotic mitochondrial ribosomes also have 70S streptomycin, gentamicin- insert at 30S and cause misread of mRNA code tetracycline- blocks tRNA attach on the A site and stops synthesis
97
Chloramphenicol bind to ___S and _____ formation fo peptide bond
50S inhibits peptide bond formation
98
Erythromycin binds to ___S and ____ movement of ____
50S blocks movement pr ribosome; stopping the elongation
99
tetracyclines ____ w attachment of _____ to _______
interferes tRNA to mRNA ribosome complex
100
Gentamycin and streptomycin does what to the ____S portion leading to what?
changes shape of 30S causing it to read incorrectly
101
drugs that affect metabolic pathways
sulfonamides BLOCK enzymes needed for folic acid synthesis needed in DNA and RNA synthesis via competitive inhibition
102
drug resistance adaptive acquired (CTT)
adaptive- the microorg begins to tolerate drug due to genetic variatio acquired: how genetic variation is achieved, acquisition of new bacterial genes ( new proteins and properties) conjugation: DNA transfer via pili Transduction: bacteriophage transfer transformation: free DNA uptake from environment
103
mechanisms of drug resistance due to new protein expression
decrease permeability to drug drug inactivation by enzymatic activity change in drug receptors more elimination of drug from cell (protein pumps drug out) change in metabolic pathway, new enzymes bypass blocked enzyme
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