UNE CHEM 1005 Midterm Study Guide
Questions With Complete Solutions
What enzyme is used by the gluconeogenic pathway but NOT in
the glycolytic pathway? correct answer: Phosphoenolpyruvate
Carboxykinase PEPCK
Newborn screening results show a biotinidase deficiency in a 2
day old infant. The deficiency impairs the infant's ability to
reuse and recycle biotin. Due to the enzymatic deficiency, the
activity of what enzyme is likely impaired? correct answer:
Pyruvate carboxylase
If unregulated, which of the following pairs of enzymes would
represent a futile cycle? correct answer: Fructose 1,6 -
bisphosphate and phosphofructokinase-1
When cortisol binds to its receptor, which of the following
events occur top stimulate gluconeogenesis? correct answer:
Enhanced transcription of regulatory enzymes
What compound allosterically activates pyruvate carboxylase
correct answer: Acetyl-CoA
When the insulin to glucagon ratio is low, glycogenolysis is
activated in the liver. Which of the following is primary fate of
the glucose 6-phosphate released under these conditions? correct
answer: Dephosphorylated and released into the blood to
maintain blood glucose
, What are the two major contributors to maintaining blood
glucose levels during fasting? correct answer: Hepatic
glycogenolysis and gluconeogenesis
Pyruvate dehydrogenase complex is highly regulated. The
enzyme that will be most active when which of the following
compounds is high? correct answer: Pyruvate
A deficiency in thiamine can reduce the activity of the pyruvate
dehydrogenase complex. Under these conditions, you would
expect a higher than normal blood concentration of which of the
following metabolites? correct answer: Pyruvate
A-ketoglutarate dehydrogenase is the enzyme responsible for
one of the irreversible reactions in the TCA cycle, What
conversion does it catalyze? correct answer: A-ketoglutarate to
succinyl-CoA
A 10-year old girl is swimming in a local competition. The
intense exercise will increase intracellular calcium levels which
in turn will increase flux thru the TCA cycle by stimulating the
activity of all of the following enzymes EXCEPT correct
answer: Succinate Thiokinase
TCA Cycle intermediates are always being removed for various
reasons but the cycle does not run out of intermediates and stop.
This is because the TCA cycle can replenish intermediates thru
correct answer: Using anaplerotic reactions
Questions With Complete Solutions
What enzyme is used by the gluconeogenic pathway but NOT in
the glycolytic pathway? correct answer: Phosphoenolpyruvate
Carboxykinase PEPCK
Newborn screening results show a biotinidase deficiency in a 2
day old infant. The deficiency impairs the infant's ability to
reuse and recycle biotin. Due to the enzymatic deficiency, the
activity of what enzyme is likely impaired? correct answer:
Pyruvate carboxylase
If unregulated, which of the following pairs of enzymes would
represent a futile cycle? correct answer: Fructose 1,6 -
bisphosphate and phosphofructokinase-1
When cortisol binds to its receptor, which of the following
events occur top stimulate gluconeogenesis? correct answer:
Enhanced transcription of regulatory enzymes
What compound allosterically activates pyruvate carboxylase
correct answer: Acetyl-CoA
When the insulin to glucagon ratio is low, glycogenolysis is
activated in the liver. Which of the following is primary fate of
the glucose 6-phosphate released under these conditions? correct
answer: Dephosphorylated and released into the blood to
maintain blood glucose
, What are the two major contributors to maintaining blood
glucose levels during fasting? correct answer: Hepatic
glycogenolysis and gluconeogenesis
Pyruvate dehydrogenase complex is highly regulated. The
enzyme that will be most active when which of the following
compounds is high? correct answer: Pyruvate
A deficiency in thiamine can reduce the activity of the pyruvate
dehydrogenase complex. Under these conditions, you would
expect a higher than normal blood concentration of which of the
following metabolites? correct answer: Pyruvate
A-ketoglutarate dehydrogenase is the enzyme responsible for
one of the irreversible reactions in the TCA cycle, What
conversion does it catalyze? correct answer: A-ketoglutarate to
succinyl-CoA
A 10-year old girl is swimming in a local competition. The
intense exercise will increase intracellular calcium levels which
in turn will increase flux thru the TCA cycle by stimulating the
activity of all of the following enzymes EXCEPT correct
answer: Succinate Thiokinase
TCA Cycle intermediates are always being removed for various
reasons but the cycle does not run out of intermediates and stop.
This is because the TCA cycle can replenish intermediates thru
correct answer: Using anaplerotic reactions
