ETC and Oxidative Phosphorylation

Question 1

Rotenone

Answer 1

ETC poison. pesticide. stops at Q. inhibits e- transfer from Complex 1 to Q (UbiQuinone) (step 1). everything upstream (complex 1) remains reduced, downstream (Q,3,4) remains oxidized. no proton motive force, no ox phos, no energy

Question 2

Antimycin A

Answer 2

ETC poison. fish poison. blocks Cytochrome C Oxidoreductase. stops at 3. inhibits Cyto C from transferring e- from Q to Complex 3. everything upstream (complex 1, Q) remains reduced. everything downstream (3,4) remains oxidized. no proton motive force, no ox phos, no energy

Question 3

CN-/CO

Answer 3

ETC poison. inhibits cytochrome OXIdase (transfers e- to OXYgen) in Complex 4. transfer of e- from 4 to O2. everything upstream (everything remains reduced (?)). no proton motive force, no ox phos, no energy

Question 4

Oligomycin

Answer 4

inhibits F0. no H+ flow.

Question 5

DNP, FCCP

Answer 5

uncoupler: dissipates H+ gradient. does not affect ETC like ETC poisons.

Question 6

thermogenin (not a poison)

Answer 6

natural uncoupling. brown fat. generates heat.