Exam 2 Lecture 19 Citric Acid Cycle Flashcards
TCA takes place where?
Inside the mitochondria
TCA cycle does what to carbon fuels?
Oxidizes carbon fuels for harvesting high energy electrons
T/F: TCA cycle is amphibolic
True performs catobolism and anabolism
T/F: TCA cycle is not a source of precursors for biosynthesis
False. Is a source for biosynthesis
TCA stands for:
Tricarboxylic acid cycle
What are the high energy e- carries of the TCA cycle?
NADH
FADH2
GTP
Oxidative phosphorylation happens in :
Mitochondria
ATP production:
1 NADH = _ ATP
1 FADH2 _ ATP
1 GTP = _ ATP
1 NADH = 2.5 ATP
1 FADH2 = 1.5 ATP
1 GTP = 1 ATP
What are types of energy nutrients that will be degraded for the TCA cycle?
Fats, polysaccharides, and proteins
Oxidation of 2-carbon units produce:
- 2 CO2 molecules
- 1 GTP
- high energy e-s in the form of NADH and FADH2
Acetyl CoA is the activated form of:
Acetate
Acetyl CoA is obtained from what 3 energy nutrients?
- Carbohydrates (glucose oxidized into 2 pyruvate, 2 pyruvate decarboxylation into 2 acetyl CoA)
- Lipids (TAG beta-oxidation into acetyl CoA)
- Proteins (breakdown into various amino acid and converted to acetyl CoA)
What are the 3 steps of pyruvate to acetyl CoA
- Decarboxylation (CO2 removed)
- Oxidation (2 e- leaving)
- Transfer acetyl group to coenzyme A
T/F: In converting pyruvate to acetyl CoA, reactions are coupled to preserve energy to drive formation of NADH and acetyl CoA
True
Pyruvate utilizes _ to enter the mitochondria
Mitochondrial pyruvate carrier (MPC)
What enzyme catalyzes the decarboxylation of pyruvate?
Pyruvate dehydrogenase complex (PDC)
What are the 3 enzymes required for the pyruvate dehydrogenase reaction
E1, E2, E3
What are the coenzymes for the pyruvate dehydrogenase reaction
- TPP
- Lipoic acid
- FAD
- CoA
- NAD+
Of the 5 coenzymes for the pyruvate dehydrogenase reaction, which are the catalytic cofactors?
TPP
Lipoic acid
FAD
Of the 5 coenzymes for the pyruvate dehydrogenase reaction, which are stoichiometric cofactors?
CoA
NAD+
PDC/PDH is regulated via
Allosteric interactions and reverse phosphorylation
Hight amounts of acety CoA directly inhibits _
PDH/C complex subunit E2 ie increases phosphorylation (kinase) to inactivate PDH/PDC
Accumulation of ADP and pyruvate activates _
Phosphatases ie active PDH/PDC
What is the common currency for the TCA cycle?
acetyl CoA
PDH links _ to the citric acid cyle (TCA)
Glycolysis