Lecture 26 - Regulation of Oxidative Phosphorylation Flashcards
What are factors affecting proton motif force (pmf).
L26 S5
- pH
- membrane potential
What are the subunits of ATP synthase?
L26 S9
α:
-3 form half of hexamer
β:
- 3 form half of hexamer
- catalytically active portion of hexamer
γ:
- part of stalk
- center of hexamer
δ:
-part of stalk
What is the function of cristae in the mitochondria?
L26 S11
Allows for efficient establishment of proton gradient
How many protons are required to generate a molecule of ATP?
L26 S13
3+1
What is responsible for ADP/ATP transport in the mitochondria?
L26 S15
ATP-ADP translocation family (complex VI)
Exchanges ATP for ADP; both must be present
Neither are permeable without this molecule
How does NADH enter the mitochondria in different organs?
L26 S16
Malate-aspartate shuttle:
- high energy electrons from cytosolic NADH are transferred to malate which enters mitochondria and then transferred to mitochondrial NAD+
- enters at complex I
- found in heart, liver, and kidney
Glycerophosphate shuttle:
- high energy electrons from cytosolic NADH are transferred to glycerol 3-P which enters mitochondria and then transferred to FAD
- enters at CoQ
- found in muscle and brain
What does CO, cyanide, and H2S inhibit and what is the result?
L26 S21
Complex IV of the electron transport chain.
Decrease proton gradient and inhibits ATP synthesis.
What are the key regulators of cellular respiration?
L26 S20
High energy charge inhibits PDH
Low energy charge activates PDH
What is uncoupling and what does it result in?
Where is this most commonly seen?
L26 S22
Uncoupling uses H+ gradient to generate heat instead of ATP.
Hydrogens pass through protein called thermogenin (UCP-1) which transports them into cytoplasm and generates heat.
Found most commonly in brown adipose mitochondria.
What is an inhibitor of ATPase?
L26 S13
Oligomycin
