Microbial Metabolism Flashcards
what are the 4 processes that form cellular metabolism?
Enzyme mediated Catalysis, reaction coupling, energy harvesting by redox reactions, use of membranes to form gradients of charge and chemical concentration
What ion is included in fueling
PO4 3-
What type of energy is used in fueling products
ATP, PMF
What 2 ions are used in biosynthesis after fueling products?
SO4 2-, and NH3
what macromolecules make lipids and lipopolysaccharide?
Fatty acids
What building block makes lipolysaccharide, glycogen, and murein?
sugars
what building block makes murein and protein?
amino acids
What building block makes RNA and DNA?
nucleotides
What structure does glycogen contribute to?
Inclusions
What macromolecules contribute to the cell envelope?
Lipid, lipopolysaccharide, murein, and protein
what macromolecule is the pili assembled from
protein
what macromolecules contribute to building cytosol?
protein and RNA
What macromolecules contribute to building ribosomes?
Protein and RNA
What macromolecules contribute to building the nucleoid?
Protein and DNA
What is active transport?
How cells accumulate solutes AGAINST the concentration gradient
What are the 3 classes of transporters?
simple transport
group translocation
ABC system
What energy source dives simple transport?
Proton Motive Force
What energy source drives group translocation?
phosphoenolpyruvate
What energy source drives ABC transporters?
ATP
What is a symport?
H+ and solute are transported in one direction
What is an antiport?
H+ and solute are transported in opposite direction
What is an example of a symport?
E.Coli lac permease
What is an example of an antiport?
sodium proton antiporter
What happens to a substance that is transported by group translocation?
it is chemically modified
what is an example of a group translocation system/
Phosphotransferase system in E.Coli
What macromolecules does phosphotransferase use?
glucose, fructose, and mannose
How many proteins are required for phosphotransferase?
5
Where does the phosphoenolpyruvate energy used in phosphotransferase come from?
glycolysis
What type of affinity does ABC systems have to substrates?
HIGH
what proteins are required for Gram negatives in ABC systems
transmembrane, ATP hydrolyzing, adn periplasmic binding protein
What proteins are required for gram positives in ABC systems?
transmembrane, ATP hydrolyzing, and substrate binding on external surface of cytoplasmic membrane
Define Metabolism
the sum of all chemical reactions that occur in a cell
Define catabolism
energy releasing metabolic reactions
Where do chemoorganotrophs get their energy?
from organic chemicals
Where do chemolithotrophs get their energy?
Oxidizing inorganic compounds
Where do Phototrophs get their energy>
convert light to ATP
Where do heterotrophs get their energy
Obtaining carbon from organic substances
Where do autotrophs get their energy
obtaining carbon from CO2
What is the reducing power in fueling products?
NADH
What do fueling reactions supply?
Energy, Reducing power, and 13 precursor metabolites
What does the entry process do?
Move organic and inorganic food substrates from enviornment into the cell
What does the Feeder pathway do>
convert intracellular food substrates into a metabolite of central metabolism
what is central metabolism?
a group of pathways which produce all the precursor metabolites
What is the simplest way to generate ATP?
Substrate level phosphorylation
What is the first step of substrate level phosphorylation?
A organic substrate becomes phosphorylated
What is the second step of substrate level phosphorylation?
The phosphorylated substrate is oxidized and energy is trapped
What cycles is substrate level phosphorylation pertinent to?
glycolytic pathway and TCA cycle
What is the equation for lactic acid fermentation?
Pyruvate + NADH—-> lactic acid + NAD+
where is lactic acid fermentation found?
bacteria, some protozoa, human skeletal muscle
what are the bacteria that produce only lactic acid?
homolactic fermenters
What are the bacteria that produce other products beside lactic acid such as ethanol, CO2?
heterolactic fermenters
How many steps is alcoholic fermentation?
2
what are the 2 equations of alcoholic fermentation?
pyruvate-> acetaldehyde +CO2
acetaldehyde +NADH-> ethanol +NAD+
where is alcoholic fermentation found?
fungi and yeasts mainly, but some bacteria
what are the equations for formic acid and mixed acid fermentation?
pyruvate+CoA-> acetyl CoA + formic acid
HCOOH -> CO2 +H2
Why is formic acid and mixed acid fermentations useful?
for identification
What gradient generates the most microbial energy?
transmembrane ion gradients
how is the membrane energized?
by proton motive force
What are the two components of the transmembrane ion gradient?
F0 and F1
Is the F0 portion hydrophobic or hydrophilic?
hydrophobic because it traverses the membrane and conducts ions through the F1
Where is the F1 component found?
located on the interior surface of the membrane
What is the F1 components use?
to catalyze the hydrolysis of ATP and dehydration synthesis of ATP
What are the 4 ways to generate transmembrane ion gradients?
- Respiration
- Enzyme pumps
- photosynthesis
- scalar reactions
Where does eukaryotic respiration occur?
Within the mitochondrial membrane complex
What type of respiration is it when O2 is the final electron acceptor which results in reduction of O2 to water
aerobic
what type of respiration is present when any other molecule is the final electron acceptor?
anaerobic
In photosynthesis what does light energy activate and where does it come from
an electron from chlorophyl causing it to go down the ETC to ground state chlorphyll or NADP+
what is the equation for photosynthesis?
H2A+CO2-> A + carbohydrate
cyanobacteria is an example of what type of bacteria
photoautotrophic
what is an example of anoxygenic bacteria?
purple sulfur and nonsulfer bacteria
where are the substrates and products in scalar reactions?
in the same location or compartment
what is an example of scalar reaction bacteria?
oxalobacter formigenes which decarboxylate oxalate to form formate creating a proton gradient
what are the 3 pathways of central metabolism?
- glycolysis
- pentose phosphate pathway
- TCA cycle
what is another name that the glycolysis pathway goes by?
Embden Meyerhof Parnas (EMP)
what does the glycolysis pathway yield
pyruvate, other precursor metabolites, 2 NADH, and 2 ATP
what is the pentose phosphate pathway for
an alternative route for converting G6P to triosephosphate
What does the pentose phosphate pathway yield?
2 additional precursors 2 NADH
The TCA cycle is fed from pyruvate through a linker precursor metabolite called…
Acetyl coenzyme A
What does the TCA cycle yield?
3 precursor metabolites, 4 NADH, 2 CO2
T or F: Bacteria and Archaea are able to reproduce sexually
false, only asexual and haploid
what is the generation time of E.Coli?
20 mins
what are the two pathways of the bacterial cell cycle?
- DNA repliaction and partition
- cytokinesis
what shape are bacterial chromosomes?
circular
what is the orgin of replication?
the site at which replication begin. There is only 1
what is a replisome?
a group of proteins needed for DNA synthesis
what does the replisome physically do?
pushes daughter chromosomes to opposite ends
what does MreB play a role in?
determination of cell shape and chromosome segregation
what happens if MreB is mutated?
the chromosomes do not segregate
what structure must form in septation?
Z ring
what kind of homolog is MreB?
an actin homolog
what type of homologue is protein FtsZ?
tubulin homologue
What forms from the polymerization of protein FtsZ?
the Z ring
What does the MinCDE system do in E.Coli?
limits the Z ring to the center of the cell
What does the MinCDE system do in general?
link the Z ring to the cell membrane
What is the function of proteins FtsA and ZipA?
anchor the Z ring to plasma membrane
What function does the FtsZ protein do?
form the z ring
what does the function FtsK hold?
chromosome segregation and seperation of chromosome dimers
what is the function of the FtsQLB protein?
a scaffold for assembly of proteins in peptidoglycan synthesis
what is the function of Ftsl and FtsW proteins?
peptidoglycan synthesis
what is the function of FtsN protein?
trigger constriction initiation
what do penicillin binding proteins (PBPs) do?
link peptidoglycan strands and catalyze controlled degradation for new growth
where does new peptidoglycan form in cocci divisome?
at the central septum
Do rods elongate before or after septation
before
what does FtsZ do in cocci divisome?
determines the site of cell wall growth and recruite PBP for synthesis of septum
what does MreB do in Rod divisome ?
determines cell diameter and elongation as Z ring forms in the center
what is a batch culture?
a closed system microbial culture of fixed volume
what is the lag phase?
the interval between inoculation of a culture and beginning of growth
the time needed for biosynthesis of new enzymes and to produce required metabolites before growth can begin
what is the log phase
rate of growth and division is constant and maximal
what growth is the most uniform and typically considered the healthiest?
log phase
what phase is typically considered balanced growth?
log phase
what are some reasons for stationary phase
nutrient limitation, limited oxygen, waste accumulation, critical population reached
What does RpoS protein assist?
Rna polymerase in transcribing genes for starvation proteins
what protein protects DNA
Dps
What is the equation for exponential growth
N=N02^n
N=final number
N0=initial cell number
n=the number of generations during the period of exponential growth
what is the equation for generation time
g=t/n
g=generation time
t=duration of exponential growth
n= number of generations
what manner do biofilms use to communicate?
quorom sensing
what type of bacteria produces AHL?
gram negative
what does AHL do once inside the cell?
induces the expression of target genes
what are cardinal temperatures?
the minimum, optimum, and maximum temperatures
where are psycrophiles found?
cold environments
where are thermophiles found?
in hot environments
what are the cardinal temperatures for psycrophiles?
opt:15
Max: 20
min: 0
what are the cardinal temperatures for psycrotolerant microbes
opt 20-40
what are some adaptations that microbes have to survive the cold?
more a helices, more polar amino acids, fewer week bonds
what is the optimum temperature for thermophiles
45-80
what is the ph optimum for neutrophiles
5.5-7.9
what is the optimum ph for acidophiles?
<5.5
what is the optimum ph for alkaliphiles
> 8
what enzymes convert H2O2 to O2 and H2O?
catalase and peroxidase
what enzyme coverts 2 O2- to H2O2 and O2?
superoxide dismutase
what enzyme converts O2- to H2O2 without producing O2
superoxide reductase
what type of acid is contained in endospores
dipicolinic acid
what is the outer layer of endospre
exosporium
what ion is endospores enriched in
Ca2+
