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What makes streak plates successful
Single colonies
What are aseptic techniques
Sterilization, making sure things are wiped down, flaming the lips of things
What are the different energy classes
Chemoorganotrophs, chemolithotrophs, phototrophs, heterotrophs, autotrophs
What is exergonic
Reactions with a negative delta G that release free energy
What is endergonic
Reactions with a positive delta G that release free energy
What does a catalyst do
Lowers the activation energy of a reaction therefore increases the reaction rate
What are typical characteristics of enzymes
Highly specific, biological catalysts, larger than substrates
What kind of enzyme is the ribosome
It is an anabolic enzyme that builds the protein up
What happens to the burning of ATP in the beginning steps of glycolysis
It helps energize the substrate so that it can be split
How many net ATP’s are produced in glycolysis
2
Does glycolysis use oxygen
Glycolysis is anaerobic
What is the purpose of fermentation
Regenerate NAD+
How many ATP’s are in aerobic glycolysis
38 ATP
How is the electron transport chain oriented in the cytoplasmic membrane
Oriented so that the electrons are separated from the protons
What does the final carrier in the ETC do
Donates the electrons and protons to the terminal electron receptor
Where do the protons originate during the proton motive force
From NADH and the dissociation of water
What is the pH gradient like in the PMF
The inside is negative and alkaline and the outside is positive and acidic
What is the importance of the CAC
It is the pathway that pyruvate is completely oxidized to CO2
From the microbes perspective, what is the main goal of the CAC
Biosynthesis, with importance on the intermediates
What happens to all the carbon in glucose
It ends up as CO2 in the CAC and prep steps
Why does bacteria need to produce sugars
For cell wall build up and for its DNA and RNA
What are the important polysaccharides for biosynthesis
N-acetylglucosamine and N-acetylmuramic acid
Why is synthesis of gluconeogenesis important
Phosphoenolpyruvate is synthesized from oxaloacetate
What are pentoses required for
The synthesis of nucleic acids
How are pentoses formed
By the removal of a carbon atom from hexose
Where do carbon skeletons come from
The intermediate steps of glycolysis or CAC
What protein is involved in fatty acids
Acyl carrier protein
What happens during the final assembly of lipids in bacteria and eukarya
The fatty acid is added to a glycerol
What happens to the final assembly of lipids in archaea
A phytanyl side chain is added to glycerol
Can all prokaryotes fix nitrogen
No
Where are nitrogen fixers found
Can be free living or symbiotically with plants
The nitrogen reaction is catalyzed by what
Nitrogenase
What are nitrogen fixing bacteria sensitive to
Oxygen
What is teh final product of nitrogen fixation
Ammonia
Why does nitrogen fixation use up so much ATP
The more waste that bacteria take up the more ATP they need to burn
How is nitrogenase assayed
With a acetylene reduction assay
What instrument is used for an acetylene reduction assay
Gas chromatograph
What is the acetylene reduction assay used for
To see if the bacteria is nitrogen fixing
What is peptidoglycan
Feature of cell wall
What is bactoprenol
A carrier molecule that inserts peptidoglycan precursors
What is the function of glycolases
Interact with bactoprenol and catalyze glycosidic bond formations
What is transpeptidation
Final step in cell wall synthesis, inhibited by penicillin
What is exponential growth
Growth of the microbial population where cells double in specific time intervals
What is a batch culture
A closed system of microbial cultures in a fixed volume
What are the growth phases of a batch culture
Lag and log phase
What phases uses binary fission in a batch culture
Log, stationary and death
What is a continuous culture
An open system of microbial culture in a fixed volume
What is a common continuous culture device
Chemostat
What is an important aspect of a chemostat
The growth rate and population density of the culture can be controlled independently and simultaneously
What controls the growth rate in a chemostat
Dilution rate
What controls the growth yield in a chemostat
Concentration of limiting nutrient
What happens if the dilution is too high in a chemostat
The organism washes out
What happens if the dilution rate is too low in a chemostat
The organism will die of starvation
How can microbial cells be enumerated
By microscopic observations or hemacytometer
Why are direct counts (microscopic counts) unreliable
Cells could be dead or alive and is hard to count if clumped
What are the 3 ways to perform plate counts
Spread, pour, spiral
What is true of every microbial colony
Is an outgrowth of a single colonies viable cells
What needs to be done to obtain an appropriate colony count
The sample needs to be diluted
What are disadvantages of spiral plating
Very expensive
What are characteristics of viable counts
Not culturally, unreliable, alive but cant grow
What are characteristics of turbidity measurements
Indirect, rapid, non destructive
What is teh measurement of turbidity called
Optical density
What measures optical density
Spectrophotometer
What characteristics of bacteria would cause changes in a standard curve
Cell size, shape, clumping
At high optical densities what happens to spectrophotometer readings
They are not as accurate
What determines the minimum growth curve
The membrane becomes stiff and ‘gelling’
What determines the maximum growth curve
Protein denaturing
What is a psychrophile
Grows in low temperatures
What is a mesophile
Grows in midrange temps
What is a thermophile
Grows in high temps
What is a hyperthermophile
Grows in extremely high temps
What would be most associated with the human body
Mesophiles
What kind of fatty acids are in psychrophiles
Unsaturated fatty acids
What kind of fatty acids are in thermophiles
Saturated fatty acids
What kind of bacterial diversity is found in hyperthermophiles in hot springs
High prokaryotic diversity
What enzyme is produced by hyperthermophiles
Taq polymerase
What motive force does some alkaliphiles have
Sodium motive force
What is the internal pH of a cell
Close to neural, outside the cell can be high or low pH
Bacteriostatic
Prevents microbial growth
Bacteriocidal
Kills the cell
Bacteriolytic
Kills and lysis the cell
What does MIC stand for
Minimum inhibitory concentration
Why is the MIC needed
To inhibit growth of microorganism with the smallest amount of agent
What is a disc diffusion assay
Solid media with an antimicrobial gent added to filter paper disks
Does a larger inhibition zone when doing a disk assay mean its a better antimicrobial
The diameters don’t related to activity it means that there is activity
Where do haalophiles form best
In areas with high salt concentration and reduced water potential
Where do osmophiles grow best
In high sugar environments
Where do xerophiles grow best
In dry environments
What ways can reduce microbial growth
Microwaves, UV, x-rays, gamma rays,
What could be missing in a bacterial cell wall
A cell wall
What domain makes up 60% of all biomasses on earth
Bacteria
Genetic material of prokaryotic cells
Consist of chromosomes and plasmids, usually circular and double stranded, consists of multiple chromosomes, contain millions of base pairs
The person who first described bacterial cells was
Anton Van Leeuwenhoek
The person who debunked spontaneous generation
Louis Pasteur
The father of infectious disease
Robert koch
What does a pure culture refer to
Only a single type of organism in the culture
Koch’s postulates are designed to
Determine the causal agent of a disease
A main advantage of microbial cells being small is
Greater surface to volume ratio
Most membrane associated transport proteins would be
Integral
Which is not a difference between gram positive and gram negative cells
Presence or absence of fermentative abilities
Note
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