ETS Flashcards
Which enzyme of ETS is located IN mito membrane?
succinate dehydrogenase
more copies of mito DNA or nuclear DNA?
mito DNA
Main Goal of ETS
overall process loses free-energy but some of this energy can be “trapped” or conserved by complexes and used to synthesize ATP
Succinate Dehydrogenase
oxidizes succinate to fumarate; takes protons from succinate and gives them to FAD to give FADH2 (utilizes FAD as coenzyme)
NADH Dehydrogenase
oxidizes NADH to NAD+ (utilizes FMN coenzyme)
Fatty Acyl-CoA Dehydrogenase
catalyzes initial step of Beta-oxidation in FA’s (uses FAD coenzyme)
Name the 4 complexes involved in the ETC.
C1 - NADH CoQ Reductase
C2 - Succinate CoQ Reductase (located in mitochondrial membrane, from TCA Cycle) (not coupled w/ ATP formation)
C3 - Cytochrome C Reductase
C4 - Cytochrome Oxidase
Why does NADH get 3 ATPs and FADH2 only get 2 ATPs per molecule?
Complex II is not coupled w/ ATP formation unlike complex I (complex I > complex II in terms of energy release
Coenzyme Q (CoQ)
not a protein, lipid instead
shuttles electrons from dehydrogenases to Complex III
Cytochrome c
shuttles electrons from complex III to complex IV
3 Complexes that Pump H+ into periplasmic space
Complexes I, III, IV
of electrons to reduce 1 molecule of H2O
4
Describe ATP synthase
F0 subunit - forms the proton channel
F1 subunit - forms the moeity that synthesizes ATP
Proton movement across the membrane must be coupled with ATP synthase or the energy created during the ETC will be lost as heat
What 2 other rxns, besides for those related to the 4 complexes, occur in the mitochondrial membrane and yield FADH2?
Glycerol phosphate shuttle from glycolysis.
Fatty Acyl CoA dehydrogenase from Beta oxidation
- both yield on FADH2
