Studied by 47 people
microbial metabolisms
doubling time is characteristic of ___ and ____
species; condition
finding ideal conditions has been possible for only ___% of bacteria
5-10
The final number of doubling is
2n
what does n =
number of divisions
What is the equation for doubling time?
nt=n0 × 2n
What is a typical doubling time ?
20 minutes
Why does M. tuberculosis have a long doubling time?
it has a thick cell wall
Cells can ____ will working
replicate
Why do cells need to replicate while working
evolutionary pressures
What are the 5 stages of the bacteria growth stage
lag, log/exponential, stationary, death, prolonged decline
What occurs during the exponential phase
replication
in the stationary phase ___ is gone and _ builds
nutrients; waste
What are the limitations of a Batch culture
cultures only last a couple days
What is industrial control of growth done in ?
bioreactor
What are 2 types of bioreactors
chemostat and continuous culture
chemostat bioreactors hold ____
conditions
What does bioreactors provide important control over?
growth state
Bioreactors allow you to maintain any _____ of cells
given density
bioreactors control ____ production of______
commercial; metabolites
What are conditions you can control for growth of microbes?
temp, pH, water availability, and oxygen
What is the abbreviation for water availability?
AW
Psychrophiles grow best in ___ temps
cold
mesophiles grow best in temps near
body temp
Thermophiles growth best in ____ temps
warm
Hyperthermophiles growth best in ___ temps
hot
What is an example of a hyperthermophile?
thermos aquatics (Yellowstone)
Why can oxygen be toxic?
it produces radicals that accept electrons in the ETC
What enzyme controls oxygen radicals ?
super oxide dismutase
What does SOD turn oxygen radicals into?
hydrogen peroxide (h2o2)
Peroxidase turns hydrogen peroxide into
water
What turns hydrogen peroxide into water and oxygen
catalase
obligate anaerobes are ___ by oxygen
poisoned
Why can’t obligate anaerobes use O2?
they lack SOD and catalase
What type of organism can grow everywhere with no preference of oxygen?
aerotolerant anaerobes
Facultative anaerobes ( need/ don’t need) oxygen
both
What are the oxygen requirements of most bacteria
facultative anaerobes
Obligate aerobes are not able to
ferment
What are obligate aerobes similar to
the brain
what are facultative anaerobes similar to?
muscle
What terms can you use to describe where microbes derive energy from?
autotrophy vs. heterotrophy, photo vs. chemo, chemoorgano vs chemolitho
auto or heterotroph refers to
carbon source
photoautotrophs energy source is
sunlight
photoautrophs carbon source is
CO2
photoheterotrophs energy source is
sunlight
photoheterotrophs carbon source is
organic compounds
what would you call a microorganism that has an inorganic chemical energy source and carbon dioxide carbon source?
chemolithoautotroph
chenoorganoheterotrophs get their energy and carbon from
organic compounds
____ can fix their own carbon
autotrophs
trees are an example of a
photoautotroph
photoheterotrophs must consume outside ____
reduced carbon
halo bacterium and bacteriorhodopsin is an example of
photoheterotrophs
chemolithoautotrophs are often
extremophiles
chemolithoautotrophs are important in ___ drainage and _____ industry
acid mine; bleaching
what are examples of chemoorganoheterotrophs
herbivores, carnivores
What is the purpose of glycolysis?
split sugars and turn into pyruvate
What is the purpose of Krebs?
releases CO2 an yields ATP
The ETC concerts _____ power into ______ gradient to yeild ATP
reducing; proton
What is the technical term for ATP Production in the ETC
oxidative phosphorylation
What is the purpose of fermentation
create more oxidized forms of NAD for glycolysis
What is the waste product of fermentation
ethanol
What does fermentation reduce?
pyruvate
What is the proton force used to drive in the ETC?
ATP Synthase
Each cytochrome in the ETC requires more ____ to pass _____
power; electrons
What is the final electron acceptor of the ETC?
oxygen
Cytochrome splits ____ and releases ____ radicals
O2; oxygen
What doesn’t happen when a cell is exposed to CO or CN (think ETC)
there is no oxygen terminal electron acceptor
What is the difference in bacteria ETC vs eukaryotic?
the proton gradient drives multiple functions
What 3 things does the proton gradient drive in aerobic bacteria?
ATP synthase, active transport, rotation of flagella
Where is the ETC located in bacteria (G+ and G-)
G-: cell membrane
G+: cell wall
bacterias ETC is (more/less) efficient
less
Bacteria are more dependent on maintaining _______ because they don’t always have _____
proton gradient; oxygen
What is different about bacterial ATP synthase?
it can reverse and act as a H+ pump when theres no ETC
Bacteriarhodopsin has a ______ proton pump
light-driven
What part of bacteriarhodopsin is sensitive to wavelengths of photons
retinal
To keep the proton gradient bacteriarhodopsin ______ light to help pump protons
isomerizes
Once NAD is reoxidizes it can go ‘back’ to _____
glycolysis
What is the net ATP production of glycolysis?
2
What are all the fermentation pathways that bacteria can do (pyruvate can be converted to)
lactic acid, ethanol, butryic acid, propionic acid, mixed acids, 2,3 butanediol
What microorganisms do lactic acid fermentation
Streptococcus Lactobacillus
What microorganism does ethanol fermentation?
Saccharomyces
What fermentation pathway does Clostridium do?
butyric acid fermentation
Propionibacterium has a ____ fermentation pathway
propionic acid
What ferements mixed acids?
E.coli
2,3 butanediol is a fermentation product of which microoraganisms?
enterobacter Klebsiella
diacetyl groups can be uses for various ____ and as _____
polymers; fuel
Why may bacterial genus/species be outdated
asexual reproduction means that they can’t cross breed s don’ts fix other definitions of species
What do fermentation pathways allow for?
glycolysis to keep going for some ATP
genera Lactobacillus, Streptococcus lactis, S. thermophilus are ______ fermenters
lactic acid
lactic acid contributes to protein _____
coagulation
WHat is the sugar source in milk
lactose
additonal metabolites add _____ in dairy products
flavor, texture, nutrients, nose
Penicillium roquefortii, p. camemberti are species in ______ (dairy product)
blue cheese (mold)
what is inculation with a human skin microbiome bacterium and predilection for epidermis of the feet
limburger cheeses
Lactic acid fermentation can be used in what products?
-milk products
-pickled vegetables
-animal medicine
what does fermentation add to pickled vegetables?
flavors and preservation
Lactobacillus spp. is in (2 products)
pickled vegetables and animal medicine
In animal medicine Lactobacillus spp. lowers local _____ and controls ____ growth
pH; pathogen
alcohol fermentation is used in what 2 products?
wine and sake
Saccharomyces cervisiae does ____ fermentation
alcohol
what is added to prevent spoilage during alcohol fermentation
SO2
Note 
Flashcard (522)