Lecture 11. Oxidative Phosphorylation Flashcards
Definition of oxidative phosphorylation
The process in which ATP is formed as a result of the transfer of electrons from NADH or FADH₂ to O₂ by a series of electron carriers
Do the respiratory complexes make ATP?
The complexes do not make ATP, they sequester the necessary energy by pumping protons into the inter-membrane space
Sequence of electron transfer to O₂ from NADH
NADH → cpx I → cpx III → cpx IV → O₂
Sequence of electron transfer to O₂ from FADH₂
FADH₂→ cpx II → cpx III → cpx IV → O₂
What is respiratory complex I?
NADH-Q oxidoreductase
What delivers electrons to complex I?
NADH
Where are the electrons delivered to in complex I?
Ubiquinone
How many protons are pumped across the membrane in complex I?
4
What is respiratory complex III?
cyt bc1 or Q cyt c oxidoreductase
What delivers electrons to complex III?
Ubiquinone
Where are the electrons delivered to in complex III?
Cytochrome C
How many electrons can cytochrome C carry?
1
How many protons are pumped across the membrane in complex III?
4
What is the Q cycle?
The relay of 2 electrons to 1 electron carrier
What is respiratory complex IV?
Cytochrome C oxidase
What delivers electrons to complex IV?
Cyt C
Where are the electrons delivered to in complex IV?
Oxygen - gets reduced to water
How many protons are pumped across the membrane in complex IV?
2
What is respiratory complex II?
Succinate-Q reductase
What is complex II directly linked to?
Citric acid cycle
Where are the electrons delivered to in complex II?
Ubiquinone
How many protons are pumped across the membrane in complex II?
0
What can multiple complexes form?
Super-complexes, respirasomes
What is the chemiosmotic theory?
The primary energy-conserving event induced by e⁻ transport is the generation of a proton-motive force across the inner mitochondrial membrane
