Flashcards in Mitochondrial Bioenergetics Deck (23):
Pyruvate enters mitochondria through what carrier?
Mitochondrial pyruvate carrier
PDC is active in what form?
Inhibitors of PDH/PDC?
Acetyl CoA (E1 subunit), High ATP and high NADH
Activators of PDH/PDC?
High AMP, Pyruvate, NAD+, Ca2+, Mg2+
Irreversible steps of TCA?
Steps: 1, 3, and 4.
1.) OAA -> Citrate via citrate synthase
2.) Isocitrate -> ≈å ketoglutarate via Isocitrate dehydrogenase
3.) å ketoglutarate -> succinyl CoA via å ketoglutarate dehyrdogenase
Products of TCA cycle?
3 NADH = 2.5 ATP
1 FADH2 = 1.5 ATP
1 GTP = 1 ATP
CO2 is byproduct
Steps that produce NADH?
Isocitrate -> å ketoglutarate
å ketoglutarate -> succinyl CoA
Malate -> OAA
Steps that produce FADH2?
Succinate -> Fumarate via Succinate dehydrogenase
Steps that produce GTP?
Succinyl CoA -> Succinate via Succinate thiokinase
Rate limiting step of TCA? Activators? Inhibitors?
Isocitrate dehydrogenase. Activators are Isocitrate, ADP, and Ca2+. Inhibitors are NADH and ATP.
Why isn TCA anaplerotic?
Anaplerotic rxns provide intermediates for replenishing TCA cycle => degradation of AA and Carboxylation of pyruvate.
Which of the following best explains the function of TCA?
It participates in the synthesis of glucose to pyruvic acid?
rare disorder with developmental delay and neurological problems in infants. Metabolic acidosis, microcephaly, mental retardation
Fatal outcome w/in 2 yrs of life.Encephalomyopathy, dystonia, increased urinary excretion, AR disorder.
Successful OxPhos must accomplish the following key goals:
1.) Transfer e- from NADH and FADH2 -> O2
2.) Establish a proton gradient
3.) synthesize ATP
Electrons are pumped from matrix to inner mitochondrial space
Two factors that constitute a proton motive force?
pH gradient and membrane potential
Inhibitors of ATP synthase (Complex V)
Oligomycin disrupts proton transport through the channel
Mobile carriers of ETC?
CoQ (ubiquinone) and Cytochrome C
Uncoupling mechanism and example
DNP -> Protons reenter the mitomatrix from the innerrmembrane space: TCA cycle and e- transfer to O2 are accelerated, ATP synthase is inhibited, and Heat is generated.
Which would not occur upon treatment of DNP to mitochondria ?
Increase in the P/O ratio?