Terminal Respiration Flashcards
Pathway of electron movement from reduced substrates to oxygen in the mitochondrion
Electron transport chain - e’s flow through chain
energy is conserved from breakdown of food molecules leading to oxidation of NADH,FADH2, ubiquinone and cytochrome
4 complexes
The generation of a proton conc. gradient across the inner mitochondrial membrane
chemiosmosis - as e’s pass through the complexes of the transport chain protons move from matrix to outside the inner mitochondrial membrane, movement has spatial directionality
proton motive force - protons on outside membrane act as store of potential energy, when the protons are “allowed” to flow back down their gradient they release energy to do work
What is complex 1
NADH Q oxidoreductors oxidise NADH and passes the high energy e’s to ubiquinone to give ubiquinol (QH2)
utilises Fe-S centres and FMN (flavin mononucleotides)
pumps H+ ions into the intermembrane space
What is complex 2
succinate-Q reductase
oxidised FADH2 and passes high-energy e’s to ubiquinone which becomes ubiquinol
utilises Fe-S centres to channel e’s
energy is also part of the citric acid cycle under the guise of sucinate dehydrogenase
What is complex 3
Q-cytochrome C oxidoreductase
takes the e’s from ubiquinol and passes them to cytochrome c
1 ubiquinol is oxidised to yield two reduced cytochrome c molecules
pumps protein into intermembrane space
What is complex 4
cytochrome c oxidase
takes the e’s from cytochrome c and passes them to molecule O2
e’s channelled through Fe-Cu centre
pumps protons into intermembrane space
ATP synthase structure
F1 - protrudes into mitochondrial matrix and acts as the catalyst for ATP synthesis
produces lots of ATP from proton motive energy collected from F0
F0 - membrane bound proton conducting unit
10 subunits, separate subunit connects F0-F1
ATP synthase function
ADP +Pi enter B subunit
rotation of F0 cylinder only shaft forces conformation changes in the B subunits of F1
conformational changes catalyse the ADP- ATP conversion and release ATP
reaction coordinate diagram shows the proton gradient drives release of ATP and not formation of ATP
