The citric acid cycle is an example of an amphibolic pathway.
The molecule shown is:
Biotin
Coenzyme A
Acetyl-CoA
Flavin mononucleotide
Lipoamide
The molecule shown above is a cofactor of:
succinate dehydrogenase
citrate synthase
alpha-ketoglutarate dehydrogenase
succinyl-CoA synthetase
pyruvate carboxylase
Which one of the following enzymes of the citric acid cycle catalyzes an irreversible step?
isocitrate dehydrogenase
fumarase
malate dehydrogenase
Which of the following conditions decreases the rate of oxidation of acetyl-CoA by the citric acid cycle?
a low ATP/ADP ratio
a low NAD+/NADH ratio
a low GTP/GDP ratio
a high NAD+/NADH ratio
an increase in Ca2+ concentration
In eukaryotes the enzymes of the citric acid cycle are found in the cytosol.
The citric acid cycle is an anaerobic pathway.
The only reaction in the citric acid cycle that produces a carbon-carbon bond is catalyzed by citrate synthase.
Which enzyme is unique to the glyoxylate cycle?
malic enzyme
isocitrate lyase
PEP carboxylase
The only reaction of the citric acid cycle that provides substrate level phosphorylation is catalyzed by:
pyruvate dehydrogenase
biotin
coenzyme A
FAD
flavin mononucleotide
lipoamide
In mammalian tissues, isocitrate dehydrogenase is allosterically stimulated by
high ATP/ADP ratio
low NAD+/NADH ratio
low acetyl CoA/CoA ratio
high NAD+/NADH ratio
a decrease in Ca2+ concentration
In eukaryotes the enzymes of the citric acid cycle are found in the mitochondria.
The only reaction in the citric acid cycle that produces substrate level phosphorylation is catalyzed by citrate synthase.
All of the statements below about the glyoxylate pathway are true EXCEPT:
The enzymes of the glyoxylate pathway are found in the glyoxysomes.
The glyoxysomes contain all of the enzymes of the citric acid cycle.
The glyoxylate pathway allows plants, yeast, and microorganisms to thrive using acetate as the sole carbon source.
The glyoxylate pathway bypasses the two oxidative decarboxylation reactions of the citric acid cycle.
In the glyoxylate pathway, isocitrate is routed through isocitrate lyase and malate synthase.
The anaplerotic reactions associated with the citric acid cycle are a result of:
The use of many of the citric acid cycle intermediates in biosynthesis.
The oxidative nature of the citric acid cycle.
The decarboxylation reactions of the citric acid cycle.
The production of reduced coenzymes.
The irreversible nature of three citric acid cycle reactions.
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