BIO 207 UMICH EXAM 2 QUESTIONS AND ANSWERS ALREADY PASSED GRADED A+
Proton motive force - Answers drives protons across membrane
Stores energy to make ATP
Electron transport system - Answers Electrons move from reduced food molecules onto energy carriers,
then onto membrane protein carriers, and then onto oxygen or oxidized minerals.
Converts energy into ion potential across membrane (PMF)
Most energy-yielding reactions involve transfer of electrons from ____ to _____ - Answers reduced
donor; oxidized acceptor
Organotrophy ETS - Answers Organic electron donors and inorganic OR organic terminal electron
acceptors
Lithotrophy ETS - Answers Inorganic electron donors and inorganic OR organic terminal acceptors
Phototrophy ETS - Answers involves light capture by chlorophyll, usually coupled to splitting of H2S or
H2O or organic molecules
Reduction potential - Answers tendency of a compound to accept electrons
Delta G - Answers Change in free energy
Proportional to reduction potential between oxidized form and reduced form
What is a favored reaction - Answers Positive E
Negative Delta G
Standard reduction potential assumes... - Answers assumes all reactants and products equal 1M at pH 7.
Relationship between delta g and standard reduction potential - Answers positive standard reduction
potential means a negative delta g.
this would favor a reaction
Where is ETS in bacteria - Answers cell membrane
where is ETS in eukaryotes - Answers cristae folds of inner mitochondrial membrane.
Oxidoreductases - Answers electron transport proteins
- they oxidize one substrate and reduce another
,- couple different half-reactions
- consist of multiple-protein complexes that include cytochromes or non cytochrome proteins
Cytochrome - Answers colored proteins, whose absorbance spectrum shifts when there is a change in
redox state.
Pattern of cytochromes down the ETC - Answers increasing reduction potential as you go down (more
likely to gain an electron).
each time an electron is passed, there is a small amount of energy provided to the organism
What processes does PMF drive? - Answers ATP synthesis
flagellar rotation
nutrient uptake
drug efflux in pathogens
Chemiosmotic theory - Answers energy from electron transfer between membrane proteins is used to
pump across the membrane, accumulating a higher H+ concentration in the compartment outside
What can drive ATP synthesis (chemiosmotic theory) - Answers ph difference
charge difference
across a membrane
Respiratory ETS - Answers aerobic bacteria.
NADH and FADH2 transfer electrons to O2, making H2O.
Cofactors - Answers mediate the small energy transitions
1) metal ions like iron or copper, held in place with amino acid residues
2) conjugated double bonds and heteroaromatic rings, like nicotinamide ring of NAD+/NADH
Quinone - Answers electron carriers that are mobile within the membrane
example: ubiquinone, which can be reduced to ubiquinol
, Quinol - Answers carry electrons and protons laterally within a membrane between proton pumping
complexes of the ETS.
Hydrophobic and never leave membrane; thus their electrons are kept in the membrane until they
transfer out of the ETS.
After transfer, quinols revert back to quinones, capable of accepting electrons again.
Three functional components of a respiratory electron transport system - Answers 1) initial substrate or
oxidoreductase
2) mobile electron carrier
3) terminal oxidase
How many protons can E Coli pump for one NADH? Where? - Answers 8 H+
4 in first complex, 2 later.
Fo - Answers embedded in membrane, pumps protons
F1 - Answers protrudes in the cytoplasm, generates ATP
oxidative phosphorylation - Answers the whole process of deriving this energy from protons.
proton-driven synthesis of ATP will end this cycle.
Proton flux - Answers drives the ATP synthase to work.
Sodium motive force - Answers analagous to PMF.
includes electrical potential plus sodium ion concentration gradient.
some bacteria might do this instead. Also, extreme halophilic archaea might do this.
Obligate aerobes - Answers grow only using O2 as terminal electron acceptor
What are some other terminal electron acceptors that prokaryotes might use? - Answers metlas,
oxidized ions of nitrogen and sulfur
anaerobic respiration - Answers occurs where oxygen is scarce
- unique to prokaryotes
- wetland soil and human digestive tract
Proton motive force - Answers drives protons across membrane
Stores energy to make ATP
Electron transport system - Answers Electrons move from reduced food molecules onto energy carriers,
then onto membrane protein carriers, and then onto oxygen or oxidized minerals.
Converts energy into ion potential across membrane (PMF)
Most energy-yielding reactions involve transfer of electrons from ____ to _____ - Answers reduced
donor; oxidized acceptor
Organotrophy ETS - Answers Organic electron donors and inorganic OR organic terminal electron
acceptors
Lithotrophy ETS - Answers Inorganic electron donors and inorganic OR organic terminal acceptors
Phototrophy ETS - Answers involves light capture by chlorophyll, usually coupled to splitting of H2S or
H2O or organic molecules
Reduction potential - Answers tendency of a compound to accept electrons
Delta G - Answers Change in free energy
Proportional to reduction potential between oxidized form and reduced form
What is a favored reaction - Answers Positive E
Negative Delta G
Standard reduction potential assumes... - Answers assumes all reactants and products equal 1M at pH 7.
Relationship between delta g and standard reduction potential - Answers positive standard reduction
potential means a negative delta g.
this would favor a reaction
Where is ETS in bacteria - Answers cell membrane
where is ETS in eukaryotes - Answers cristae folds of inner mitochondrial membrane.
Oxidoreductases - Answers electron transport proteins
- they oxidize one substrate and reduce another
,- couple different half-reactions
- consist of multiple-protein complexes that include cytochromes or non cytochrome proteins
Cytochrome - Answers colored proteins, whose absorbance spectrum shifts when there is a change in
redox state.
Pattern of cytochromes down the ETC - Answers increasing reduction potential as you go down (more
likely to gain an electron).
each time an electron is passed, there is a small amount of energy provided to the organism
What processes does PMF drive? - Answers ATP synthesis
flagellar rotation
nutrient uptake
drug efflux in pathogens
Chemiosmotic theory - Answers energy from electron transfer between membrane proteins is used to
pump across the membrane, accumulating a higher H+ concentration in the compartment outside
What can drive ATP synthesis (chemiosmotic theory) - Answers ph difference
charge difference
across a membrane
Respiratory ETS - Answers aerobic bacteria.
NADH and FADH2 transfer electrons to O2, making H2O.
Cofactors - Answers mediate the small energy transitions
1) metal ions like iron or copper, held in place with amino acid residues
2) conjugated double bonds and heteroaromatic rings, like nicotinamide ring of NAD+/NADH
Quinone - Answers electron carriers that are mobile within the membrane
example: ubiquinone, which can be reduced to ubiquinol
, Quinol - Answers carry electrons and protons laterally within a membrane between proton pumping
complexes of the ETS.
Hydrophobic and never leave membrane; thus their electrons are kept in the membrane until they
transfer out of the ETS.
After transfer, quinols revert back to quinones, capable of accepting electrons again.
Three functional components of a respiratory electron transport system - Answers 1) initial substrate or
oxidoreductase
2) mobile electron carrier
3) terminal oxidase
How many protons can E Coli pump for one NADH? Where? - Answers 8 H+
4 in first complex, 2 later.
Fo - Answers embedded in membrane, pumps protons
F1 - Answers protrudes in the cytoplasm, generates ATP
oxidative phosphorylation - Answers the whole process of deriving this energy from protons.
proton-driven synthesis of ATP will end this cycle.
Proton flux - Answers drives the ATP synthase to work.
Sodium motive force - Answers analagous to PMF.
includes electrical potential plus sodium ion concentration gradient.
some bacteria might do this instead. Also, extreme halophilic archaea might do this.
Obligate aerobes - Answers grow only using O2 as terminal electron acceptor
What are some other terminal electron acceptors that prokaryotes might use? - Answers metlas,
oxidized ions of nitrogen and sulfur
anaerobic respiration - Answers occurs where oxygen is scarce
- unique to prokaryotes
- wetland soil and human digestive tract
