KREBS CYCLE!!! Flashcards
Where does the citric acid cycle occur?
Mitochondrial matrix
What does CAC accomplish for the cell?
Tranfers 8 electrons froma acetyl CoA to reduce NAD+ and FAD to form 3NADH and 1FADH2 that are later oxidized to produce ATP. Also produces 1 GTP by SLP and 2CO2 as waste
What is the overall net reaction
Acetyl CoA + 2NAD+ + FAD+ + GDP +Pi + 2H2O –> CoA + 2CO2 + 3NADH + 3H+ = FADH2 + GTP(ATP)
What are the key enzymes in the CAC
pyruvate dehydrogenase, citrate cynthase, isocintrate dehydrogenase, alpha-ketoglutarate dehydrogenase
What is an example in everyday biochemistry?
Fluroacetate disrupts the CAC in plants by binding to coenzyme A
What does pyruvate dehydrogenase do?
Converts pyruvate to acetyl coA
What are the five coenzymes the pyruvate dehydrogenase complex needs?
-NAD+ FAD CoA TPP lipoamide
What are the four vitamins required to synthesize the coenzymes
Vitamin B3 (NAD+) Vitamin B2 (FAD) Pantothenic acid (CoA) B1 (Thiamine)
FAD and FMN can only transfer __ electron at a time to be come partially reduced to ______
one, semiquinone
What are the two fates of acetyl-coA
can be metabolized to ATP or used to store energy as fatty acids
What are the products after one turn of the CAC
3NADH
FADH2
GTP
2CO2 (waste)
What is teh net reaction for CAC 1
Acetyl CoA + Oxaloacetate + H2O –> (Citrate synthease) CoA + Citrate
What is teh net reaction for rxn 3
Isocitrate + NAD+ —> (Isocitrate dehydrogenase) alpha ketoglutarate + NADH + CO2 + H+
What is the net reaction for rxn 4
alpha-ketoglutarate + CoA + NAD+ –> (alpha-ketoglutarate dehydrogenase) Cuccinyl - CoA + NADH + CO2 + H+
What are the three factors that regulate the CAC
substrate availability
inhibition by accumulating products
allosteric feedback inhibition that catalyze early steps in the cycle
