Mitochondrial Bioenergetics Flashcards
Explain pyruvate dehydrogenase phosphatase (PDP)…
Dephosphorylates/Activates PDC
*Mg dependent
Explain pyruvate dehydrogenase kinase (PDK)…
Phosphorylates/Inactivates PDC
What are the cofactors of the subunits of the PDC?
E1 = TPP (B1) E2 = Lipoic acid E3 = NAD+, FAD
Explain citrate synthetase…
Oxaloacetate + Acetyl-CoA –> citrate (TCA cycle)
Explain aconitase…
Citrate –> isocitrate (TCA cycle)
Explain isocitrate dehydrogenase…
Isocitrate –> alpha-KG (TCA cycle)
- Rate limiting step
- produces NADH
Explain alpha-KG dehydrogenase…
Alpha-KG –> succinyl-CoA (TCA cycle)
*produces NADH
What are the amino acid derivatives of the major TCA cycle intermediates? Pyruvate, acetyl-CoA, alpha-KG, succinyl-CoA, fumarate, oxaloacetate
Pyruvate = Cys, Ala, Ser Acetyl-CoA = Leu Alpha-KG = Glu (from Gln, His, Arg, Pro) Succinyl-CoA = Ile, Val, Met, Thr Fumarate = Tyr (from Phe) Oxaloacetate = Asp (from Asn)
What are the 3 disorders of the TCA cycle talked about on the slides? What do they cause?
2-oxoglutaric acid aciduria - severe neuro problems in infants.
Fumarase deficiency - increased urinary excretion of fumarate.
Succinyl-CoA synthetase deficiency - hypotonia, dystonia, muscle atrophy
What inhibits complex I of the ETC?
Amytal, rotenone, myxothiazol, piercidin A
What inhibits complex II of the ETC?
Malonate
What inhibits complex III of the ETC?
Antimycin
What inhibits complex IV of the ETC?
Cyanide, CO, H2S
What inhibits complex V of the ETC?
Oligomycin
When the ATP:ADP ratio is high, what happens to the ATP synthase?
Decrease ATP production
What does DNP do?
Serves as an uncoupling agent of ATP synthase
What are Sx of mitochondrial disorders?
Decreased energy production
Increased free radical production
Lactic acidosis
