Chapter 14 : Electron Flow Flashcards
where is ETS located in Gram positive cells?
in cytoplasmic membrane
where is ETS located in Gram negative cells?
in the inner cytoplasmic membrane that separates cytoplasm from periplasm b/c outer membrane surrounding periplasm is permeable to protons so it does not store energy
where does the electrical potential of the proton motive force come from?
the separation of charge between the cytoplasm(more negative) and the outside membrane(more positive)
how do you calculate pH difference?
pH(internal) - pH(external
what are uncouplers?
molecules taken up by cells in both protonated and unprotonated forms which can collapse the proton gradient
what do cofactors allow for?
small reversible redox changes that typically involve metal ions or conjugated double bonds and heteroaromatic rings
what are quinones?
membrane soluble carries that are reduced to quinols which allow even smaller energy transitions thatn NAD+/NADH
do quinols leave the membrane?
no, because they are hydrophobic
what is the succession of compounds nitrate is reduced to?
nitrate is reduced to nitrite, then to nitric oxide, then to nitrous oxide, then to nitrogen gas
what is the succession of compounds sulfate is reduced to?
sulfate is reduced to sulfite, then to thiosulfate, then to elemental sulfur, and then to hydrogen sulfide
what is methanogenesis?
the oxidation of H2 by CO2, releasing methane
what are thylakoids?
folded membranes with phototrophic bacteria or chloroplasts
what does Photosystem I do?
obtains e- from H2S or HS- that are transferred through ETS
what does Photosystem II do?
transfers an e- through ETS and pumps H+ to generate ATP
what does the oxygenic z-pathway do in cyanobacteria and chloroplasts?
it absorbs 8 photons, 2 e- pairs are removed from 2H2O, producing O2
