Mitochondrial Bioenergetics Flashcards Preview

Medical Biochemistry > Mitochondrial Bioenergetics > Flashcards

Flashcards in Mitochondrial Bioenergetics Deck (12):
1

Is PDC active when phosphorylated or dephosphorylated?

Just like Acetyl CoA Carboxylase, the Pyruvate Dehydrogenase Complex MUST be DEPHOSPHORYLATED for the enzyme to work!!!!!!

2

What happens if the PDC shuttle doesn't work?

You can't generate Acetyl-CoA as readily. Lactic Acidosis occurs as the body switches to anaerobic respiration in a means to try to make energy.

*** increase lactate--> increase lactic acid--> increase H+ in blood

3

What phosphorylates or deactivated the PDH Complex?

(-) NADH, (-) ATP, (-) Acetyl CoA --> PHOSPHORYLATION

4

What dephosphorylates/activates the PDH Complex?

(+) NAD+, (+)ADP, (+) Pyruvate, (+) AMP

5

What are the major products of the TCA cycle alone not including the PDC?

3 NADH
1 FADH2
1 GTP

6

What are the energy expenditures for the reduced coenzymes of the TCA cycle?

NADH-2.5ATP
FADH-1.5 ATP
GTP- 1 ATP

7

What is the rate limiting step in TCA Cycle?

ISOCITRATE DEHYDROGENASE

8

What will happen if there is an excess of alpha-ketoglutarate?

It will prohibit ISOCITRATE DEHYDROGENASE, the RATE-LIMITING STEP OF TCA CYCLE!!!!!!!!!!!!!!!!!!!

9

What are the mobile carriers in ETC?

Mobile Carriers include:

1.) Quinone (Between Complex II and Complex III)
2.) Cyt C (Between Complex III and IV)

10

Which complexes receive which electrons?

Complex I -> NADH electrons
Complex 2-> FADH2 electrons

11

Oxidative phosphorylation is regulated by which two things?

1.) 02 levels
2.) ATP: ADP Ratio

12

Two different types of mitochondrial shuttle systems.

Malate-Aspartate Shuttle System (heart, liver, kidneys)-->
-Uses ATP from glycolysis to reduce OAA to Malate so that it can be shuttled into the mitochondria and regenerated as OAA--> Produces NADH BACK

G3P shuttle system (Brain+ muscle)-->
-Converts the DHAP-->G3P
-Consumes the NADH and produces FADH2
-Result: NET LOSS OF ENERGY EXPENDITURE BECAUSE NADH (2.5 ATP) vs. FADH2 (1.5 ATP)