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Flashcards in Mitochondrial Bioenergetics Deck (23):
1

Pyruvate enters mitochondria through what carrier?

Mitochondrial pyruvate carrier

2

PDC is active in what form?

Dephosphroylated

3

Inhibitors of PDH/PDC?

Acetyl CoA (E1 subunit), High ATP and high NADH

4

Activators of PDH/PDC?

High AMP, Pyruvate, NAD+, Ca2+, Mg2+

5

Irreversible steps of TCA?

Steps: 1, 3, and 4.
1.) OAA -> Citrate via citrate synthase
2.) Isocitrate -> Ō ketoglutarate via Isocitrate dehydrogenase
3.) å ketoglutarate -> succinyl CoA via å ketoglutarate dehyrdogenase

6

Products of TCA cycle?

3 NADH = 2.5 ATP
1 FADH2 = 1.5 ATP
1 GTP = 1 ATP
CO2 is byproduct

7

Steps that produce NADH?

Isocitrate -> å ketoglutarate
å ketoglutarate -> succinyl CoA
Malate -> OAA

8

Steps that produce FADH2?

Succinate -> Fumarate via Succinate dehydrogenase

9

Steps that produce GTP?

Succinyl CoA -> Succinate via Succinate thiokinase

10

Rate limiting step of TCA? Activators? Inhibitors?

Isocitrate dehydrogenase. Activators are Isocitrate, ADP, and Ca2+. Inhibitors are NADH and ATP.

11

Why isn TCA anaplerotic?

Anaplerotic rxns provide intermediates for replenishing TCA cycle => degradation of AA and Carboxylation of pyruvate.

12

Which of the following best explains the function of TCA?

It participates in the synthesis of glucose to pyruvic acid?

13

2-oxoglutaric aciduria

rare disorder with developmental delay and neurological problems in infants. Metabolic acidosis, microcephaly, mental retardation

14

Fumarase deficiency

Fatal outcome w/in 2 yrs of life.Encephalomyopathy, dystonia, increased urinary excretion, AR disorder.

15

Successful OxPhos must accomplish the following key goals:

1.) Transfer e- from NADH and FADH2 -> O2
2.) Establish a proton gradient
3.) synthesize ATP

16

Chemiosmotic hypothesis

Electrons are pumped from matrix to inner mitochondrial space

17

Two factors that constitute a proton motive force?

pH gradient and membrane potential

18

Inhibitors of ATP synthase (Complex V)

Oligomycin disrupts proton transport through the channel

19

Mobile carriers of ETC?

CoQ (ubiquinone) and Cytochrome C

20

Antimycin inhibits....

Complex III

21

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.

22

Which would not occur upon treatment of DNP to mitochondria ?

Increase in the P/O ratio?

23

2 shuttle systems to transfer NADH across mitomembrane and where they place:

1.) malate-aspartate shuttle -> heart, liver, and kidney
2.) Glycerophosphate shuttle -> Brand and skeletal muscle