Citric Acid Cycle Flashcards
T/F citric acid cycle can happen in aerobic and anerobic conditions
False , only under aerobic conditions
In which part of the cell does the citric acid cycle take place
In the mitochondria
What is the. Name of the substrate that enters the citric acid cycle
Acetyl coa
Isocitrate accumulation inhibits what?
Isocitrate accumulation inhibits aconitase (enzyme inhibition by the product)
What occurs when there is citrate accumulation in the mitochondria ?
Citrate then moves from mitochondria to cytosol
for :
1)Fatty acid synthesis
2)Gluconeogenesis (coz. it inhibits phosphofructokinase,
the rate limiting enz in glycolysis
What are the 2 isoenzymes of of succinyl Coa are specific for which two compounds
Two isoenzymes of succinyl-CoA synthetase enzyme:
- specific for ADP
- specific for GDP [linked to gluconeogenesis; so this one must be present in tissues where gluconeogenesis occurs; e.g. liver, kidney]
What is the name of the enzyme that turns succinate to fumerate?
Succinate dehydrogenase
What is the name of the enzyme for the reaction of malate to oxaloacetate
Malate dehydrogenase
What are the products formed during one turn on the citric acid cycle
3NADH, 1 FADH2, 1 GTP
What happens to the NADH, FADH2 generated in the citric acid cycle
Electrons carried by NADH and FADH 2
are funneled into a chain of mitochondrial electrons carriers - the respiratory chain - ultimately reducing O2 to H2O
How many molecules of ATP are generated during the citric acid cycle
10
How many water molecules are consumed during the citric acid cycle
2
T/F both an ATP and a GTP are formed in the citric acid cycle
False! Only one or the other is formed!
NADH is how many ATP
2.5
FADH2 is how many ATP
1.5
How carbon atoms enter and leave the citric acid cycle
2 enter as acetyl coa , 2 leave as co2
Is the citric acid cycle :
A) Catabolic
B) Anabolic
C) Amphibolic
Amphibolic
The citric acid cycle yield _______ power in the form of NADH, FADH2
Yields reducing power in the form of NADH ,FADH2
T/f : Krebs Cycle is a Source of Biosynthetic Precursors
Glucose
Truuuueee
You
Got this!
List the 3 rate controlling enzymes of the citric acid cycle
Citrate synthase • Isocitrate dehydrogenase • a-keoglutarate dehydrogenase
High cellular conc. of which molecule would inhibit the entry of pyruvate into the citric acid cycle? AMP, Coenzyme A, NADH or Pyruvate?
Pyruvate
Which substance is a product of glycolysis, a precursor of gluconeogenesis and a precursor of the TCA cycle? Glucose, Pyruvate, ATP, or CoA?
Pyruvate
