UNE UNIT 2 EXAM QUESTIONS AND ANSWERS
A patient is found to have a rare disease in which the secretory function of the α-cells of
the pancreas is impaired. As a consequence, glucagon cannot be secreted. Direct
stimulation of which of the following pathways in liver will be impaired?
1. glycolysis
2. glycogenesis
3. TCA
4. gluconeogenesis
5. Pentose phosphate pathway - Answers -gluconeogenesis.
process of converting other amino acids into glucose. Gluconeogenesis is activated by
glucagon.
glycolysis (glucose->ATP) is activated by insulin secretion.
TCA cycle is activated by pyruvate
Glycogenesis is stimulated by insulin when glucose levels are high enough, and now
the liver can make glucose into glycogen.
Pentose phosphate pathway
A novel signaling cascade is discovered that you suspect activates a G-αs subunit.
Which of the following downstream events would be consistent with this discovery?
1. activation of adenylyl cyclase
2. decrease synthesis of cAMP
3. inhibition of adenylyl cylcase
4. activation of phosphodiesterase - Answers -1. activation of adenylyl cyclase
adenylyl cyclase is the "downstream enzyme" in glucagon signaling.
Which of the following hormones is anabolic? - Answers -Insulin
Anabolic is building this up, storage,
Catabolic is using energy, breaking down
A young woman goes to work without eating breakfast and skips lunch. In this scenario,
which of the following pathways is providing substrates used to generate ATP in the
liver?
1. glucose form hepatic glycogenolysis
2. free fatty acids
, 3. blood glucose
4. ketones - Answers -2. free fatty acids
Gluconeogenesis is activated d/t prolonged fasting. Gluconeogenesis is using free fatty
acids to produce glucose which will then be used in glycolysis.
The liver uses free fatty acids during fasting as fuel.
Ketones are an alternative form of energy
blood glucose is not correct because this person is fasting
glycogenolysis is used when ATP levels are low and low blood sugar. Blood cells use
glycogenolysis pathway for more energy
The TCA cycle is regulated allosterically at the 3 irreversible steps: citrate synthase,
isocitrate dehydrogenase and α-ketoglutarate dehydrogenase
After a meal, fructose 2,6-bisphosphate levels are elevated. This compound will
allosterically activate which of the following glycolytic enzymes?
1. PFK 1
2. PFK 2
3. Hexokinase
4. Glycogen synthase - Answers -PFK 1
Fructose 2,6 biphosphate catalyzed by PFK 2 from Fructose 6 phosphate. If fructose
2,6 biphosphate levels are high, then it means there is glucose being broken down and
PFK 1 needs to get its shit together and continue the enzymatic reactions.
Hexokinase is the enzyme that converts glucose into glucose 6 phosphate in the very
first step. elevated levels of fructose-2,6 biphosphate means there is already glucose
broken down further down in the chain. it can chill.
glycogen synthase is not used in the glycolytic pathway but rather in the glucogenesis
A 10-year-old boy is playing soccer and is sprinting after the ball. Under these
anaerobic conditions, glucose oxidation primarily results in an increase in which of the
following compounds?
1. Acetyl-CoA
2. succinate
3. Alanine
4. Lactate - Answers -Lactate
anaerobic conditions mean glucose will be broken down into pyruvate and lactate by
lactate dehydrogenase.
A patient is found to have a rare disease in which the secretory function of the α-cells of
the pancreas is impaired. As a consequence, glucagon cannot be secreted. Direct
stimulation of which of the following pathways in liver will be impaired?
1. glycolysis
2. glycogenesis
3. TCA
4. gluconeogenesis
5. Pentose phosphate pathway - Answers -gluconeogenesis.
process of converting other amino acids into glucose. Gluconeogenesis is activated by
glucagon.
glycolysis (glucose->ATP) is activated by insulin secretion.
TCA cycle is activated by pyruvate
Glycogenesis is stimulated by insulin when glucose levels are high enough, and now
the liver can make glucose into glycogen.
Pentose phosphate pathway
A novel signaling cascade is discovered that you suspect activates a G-αs subunit.
Which of the following downstream events would be consistent with this discovery?
1. activation of adenylyl cyclase
2. decrease synthesis of cAMP
3. inhibition of adenylyl cylcase
4. activation of phosphodiesterase - Answers -1. activation of adenylyl cyclase
adenylyl cyclase is the "downstream enzyme" in glucagon signaling.
Which of the following hormones is anabolic? - Answers -Insulin
Anabolic is building this up, storage,
Catabolic is using energy, breaking down
A young woman goes to work without eating breakfast and skips lunch. In this scenario,
which of the following pathways is providing substrates used to generate ATP in the
liver?
1. glucose form hepatic glycogenolysis
2. free fatty acids
, 3. blood glucose
4. ketones - Answers -2. free fatty acids
Gluconeogenesis is activated d/t prolonged fasting. Gluconeogenesis is using free fatty
acids to produce glucose which will then be used in glycolysis.
The liver uses free fatty acids during fasting as fuel.
Ketones are an alternative form of energy
blood glucose is not correct because this person is fasting
glycogenolysis is used when ATP levels are low and low blood sugar. Blood cells use
glycogenolysis pathway for more energy
The TCA cycle is regulated allosterically at the 3 irreversible steps: citrate synthase,
isocitrate dehydrogenase and α-ketoglutarate dehydrogenase
After a meal, fructose 2,6-bisphosphate levels are elevated. This compound will
allosterically activate which of the following glycolytic enzymes?
1. PFK 1
2. PFK 2
3. Hexokinase
4. Glycogen synthase - Answers -PFK 1
Fructose 2,6 biphosphate catalyzed by PFK 2 from Fructose 6 phosphate. If fructose
2,6 biphosphate levels are high, then it means there is glucose being broken down and
PFK 1 needs to get its shit together and continue the enzymatic reactions.
Hexokinase is the enzyme that converts glucose into glucose 6 phosphate in the very
first step. elevated levels of fructose-2,6 biphosphate means there is already glucose
broken down further down in the chain. it can chill.
glycogen synthase is not used in the glycolytic pathway but rather in the glucogenesis
A 10-year-old boy is playing soccer and is sprinting after the ball. Under these
anaerobic conditions, glucose oxidation primarily results in an increase in which of the
following compounds?
1. Acetyl-CoA
2. succinate
3. Alanine
4. Lactate - Answers -Lactate
anaerobic conditions mean glucose will be broken down into pyruvate and lactate by
lactate dehydrogenase.
