Micro Exam 3

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