REGULATION OF CARBOHYDRATE METABOLISM
1. Insulin facilitates energy storage in the liver. Which enzymes of carbohydrate metabolism are coordinately regulated in liver in response to insulin signaling? [check all that apply]
A. Glycogen synthase
B. Glycogen phosphorylase
C. Phosphofructokinase-1
D. Phosphofructokinase-2
E. Pyruvate kinase
2. Among the enzymes of carbohydrate metabolism listed below, which are dephosphorylated in the liver in response to insulin signaling? [check all that apply]
A. Glycogen synthase
B. Glycogen phosphorylase
C. Phosphofructokinase-1
D. Phosphofructokinase-2
E. Pyruvate kinase
3. Given that the phosphofructokinase-1 (PFK-1) enzyme is regulated by insulin, but not via (de)phosphorylation, how is this regulation accomplished?
A. Via increased transcription of the gene encoding this enzyme
B. By recruitment of pre-existing enzyme from the Golgi
C. Via allosteric regulation by fructose-2,6-bisphosphate
D. Activation by association with IRS-1
E. An inhibitory subunit of the enzyme dissociates after binding cAMP
4. Glucokinase is also regulated by insulin in liver, but not via phosphorylation. How is this regulation accomplished?
A. Via increased transcription of the gene encoding this enzyme
B. By recruitment of pre-existing enzyme from the Golgi
C. Via allosteric regulation by fructose-2,6-bisphosphate
D. Activation by association with IRS-1
E. An inhibitory subunit of the enzyme dissociates after binding cAMP
5. The same enzymes that are (de)phosphorylated by insulin action (namely glycogen synthase, glycogen phosphorylase, the PFK-2/FBPase-2 bifunctional enzyme and pyruvate kinase) are phosphorylated via glucagon and/or epinephrine action. Which kinase is responsible for these phosphorylation events?
A. Protein kinase C
B. Calmodulin-dependent protein kinase
C. Protein kinase A
D. Receptor tyrosine kinase
E. beta-ARK
6. To which receptor does epinephrine bind in order to stimulate phosphorylation of glycogen synthase, glycogen phosphorylase, PFK-2/FBPase-2 bifunctional enzyme, and pyruvate kinase?
A. alpha-1
B. alpha-2
C. glucagon
D. beta
7. To which additional adrenergic receptor subtype does epinephrine bind in order to further activate glycogen phosphorylase in liver?
A. alpha-1
B. alpha-2
C. glucagon
D. beta
8. Insulin regulates all of the following enzymes in liver. Which of these enzymes are also regulated by insulin in muscle? [check all that apply]
A. Glycogen synthase
B. Glycogen phosphorylase
C. Phosphofructokinase-1 (PFK-1)
D. Phosphofructokinase-2 (PFK-2)
E. Glucokinase
9. What activates fructose 1,6-bisphosphatase?
A. AMP
B. ADP
C. ATP
D. GDP
E. CMP
10. What inhibits fructose 1,6-bisphosphatase?
A. Fructose 1-phosphate
B. Fructose 2,6-bisphosphate
C. Fructose 1,6-bisphosphate
D. Glucose 6-phosphate
E. Glucose 1-phosphate
11. What is a very potent inhibitor of gluconeogenesis?
A. Fructose 2,6-bisphosphate
B. Fructose 1,6-bisphosphate
C. ATP
D. Ketone bodies
E. Fatty acids
12. What activates fructose 1,6-bisphosphatase?
A. Fructose 2,6-bisphosphate
B. Fructose 1,6-bisphosphate
C. ATP
D. Ketone bodies
E. Fatty acids
13. What is the rate-limiting step of glycolysis?
A. Hexokinase
B. Phosphofructokinase-1
C. Phosphofructokinase-1
D. Pyruvate kinase
E. Lactate dehydrogenase
14. What is a major feedback inhibitor of PFK-1?
A. Pyruvate
B. Acetyl-CoA
C. AMP
D. Lactate
E. ATP
15. Which intermediate of the citric acid cycle serves as a feedback inhibitor of glycolysis?
A. Citrate
B. Isocitrate
C. Succinate
D. Aconitate
E. Malate
16. What activates PFK-1?
A. ATP
B. Citrate
C. Fatty acids
D. ADP
E. Pyruvate
17. What is the sensitive indicator that ATP is being used?
A. GDP
B. GMP
C. ADP
D. AMP
E. Phosphate
18. What inhibits glucokinase?
A. Glucose
B. Glucose 6-phosphate
C. Fructose 6-phosphate
D. ATP
E. None of the listed
19. What activates pyruvate kinase?
A. ATP
B. Fructose 1,6-bisphosphate
C. Fructose 2,6-bisphosphate
D. Glucose 6-phosphate
E. Alanine
20. What inhibits pyruvate dehydrogenase complex?
A. Acetyl-CoA
B. NAD+
C. AMP
D. ADP
E. CoA
21. What activates pyruvate dehydrogenase complex?
A. Acetyl-CoA
B. NADH∙H+
C. ATP
D. ADP
E. Fatty acids
22. What is the rate-limiting step of the citric acid cycle?
A. Citrate synthase
B. Isocitrate dehydrogenase
C. Alpha-ketoglutarate dehydrogenase
D. Succinate dehydrogenase
E. Malate dehydrogenase
23. What are the regulatory enzymes of the citric acid cycle?
A. Citrate synthase
B. Isocitrate dehydrogenase
C. Alpha-ketoglutarate dehydrogenase
D. Succinate dehydrogenase
E. Malate dehydrogenase
24. Which hormone activates glycogenesis?
A. Insulin
B. Glucagon
C. Cortisol
D. Epinephrine
E. Growth hormone
25. Which hormones activate glycogenolysis in the liver?
A. Insulin
B. Glucagon
C. Cortisol
D. Epinephrine
E. Growth hormone
26. Which hormone activates glycogenolysis in muscles?
A. Insulin
B. Glucagon
C. Cortisol
D. Epinephrine
E. Growth hormone
27. Which hormones activate gluconeogenesis?
A. Insulin
B. Glucagon
C. Cortisol
D. Vasopressin
E. Growth hormone
28. Which hormone inhibits gluconeogenesis?
A. Insulin
B. Glucagon
C. Cortisol
D. Vasopressin
E. Growth hormone
29. Which pathways are activated by insulin?
A. Glycogenolysis
B. Gluconeogenesis
C. Lipolysis
D. Krebs cycle
E. Pentose phosphate pathway
30. Which pathways are inhibited by insulin?
A. Ketogenesis
B. Glycolysis
C. Glycogenesis
D. Protein synthesis
E. Lipolysis
31. Which enzymes are dephosphorylated as a result of insulin signaling?
A. Hexokinase
B. Glucokinase
C. Phosphofructokinase-1
D. Pyruvate kinase
E. Phosphoglycerate kinase
32. Which enzymes are dephosphorylated as a result of insulin signaling?
A. Citrate synthase
B. Pyruvate dehydrogenase
C. Phosphofructokinase-1
D. Phosphofructokinase-2
E. Pyruvate carboxylase
33. Which enzyme of gluconeogenesis is activated by STH?
A. Pyruvate carboxylase
B. Phosphoenolpyruvatecarboxykinase
C. Fructose 1,6-bisphosphatase
D. Glucose 6-phosphatase
34. Which enzymes are phosphorylated in glucagon signaling?
A. Hexokinase
B. Glycogen synthase
C. Glycogen phosphorylase
D. Phosphofructokinase-1
E. Glucokinase
35. What is the result of ACTH signaling?
A. Cortisol secretion
B. Glucagon secretion
C. Insulin secretion
INTEGRATION OF METABOLISM
1. Which hormone is produced in feeding?
A. Insulin
B. Glucagon
C. Cortisol
D. STH
E. ACTH
2. Indicate the site of biosynthesis of each hormone mentioned below:
1) Insulin A. Pituitary
2) Glucagon B. Alpha-cells of pancreas
3) Cortisol C. Beta-cells of pancreas
4) STH D. Adrenal cortex
5) Epinephrine E. Adrenal medulla
3. Match the states of the body with the hormonal signals:
1) Feeding A. Epinephrine
2) Fasting B. Insulin
3) Starving C. Cortisol
4) Excitement D. Glucagon
4. Which pathway protects us from hypoglycemia in starving?
A. Glycolysis
B. Glycogenolysis
C. Glycogenesis
D. Gluconeogenesis
E. Lipolysis
5. Which pathways protect us from hypoglycemia in fasting?
A. Glycolysis
B. Glycogenolysis
C. Glycogenesis
D. Gluconeogenesis
E. Lipolysis
6. Which pathways are activated in fasting?
A. Lipogenesis
B. Glycogenolysis
C. Glycogenesis
D. Gluconeogenesis
E. Lipolysis
7. Which pathways are activated in feeding?
A. Lipogenesis
B. Glycogenolysis
C. Glycogenesis
D. Gluconeogenesis
E. Lipolysis
8. What are the substrates for gluconeogenesis?
A. Pyruvate
B. Lactate
C. Glycerol
D. Alanine
E. All of the listed
9. What are the substrates for gluconeogenesis?
A. Cholesterol
B. Adenine
C. Guanine
D. Glutamine
E. Acetoacetate
10. What are the substrates for gluconeogenesis?
A. β-hydroxybutyrate
B. Palmitate
C. Stearate
D. Lysine
E. Glycine
11. Which amino acids cannot be used to regenerate glucose?
A. Leucine
B. Isoleucine
C. Lysine
D. Valine
E. Methionine
12. How much glycogen can be stored in the liver(chose the maximum)?
A. 10 g
B. 50 g
C. 100 g
D. 400 g
E. 1000 g
13. How much glycogen can be stored in muscles (chose the maximum)?
A. 10 g
B. 50 g
C. 100 g
D. 400 g
E. 1000 g
14. What is the main source of energy for muscles in fasting?
A. Glucose
B. Fatty acids
C. Amino acids
D. Ketone bodies
E. Glycogen
15. What is the main source of energy for the brain in feeding?
A. Glucose
B. Fatty acids
C. Amino acids
D. Ketone bodies
E. Glycogen
16. What fuels does the brain use in starving?
A. Glucose
B. Fatty acids
C. Amino acids
D. Ketone bodies
E. Glycogen
17. Deficiency of which enzyme enables the liver to utilize ketone bodies?
A. HMG-CoA reductase
B. HMG-CoA synthase
C. Thiolase
D. Beta-hydroxybutyrate dehydrogenase
E. CoA transferase
18. Which cells can only utilize glucose as a source of energy?
A. Erythrocytes
B. Leucocytes
C. Muscles
D. Liver
E. Kidney
19. Which organ can never utilize fatty acids as fuel molecules?
A. Kidney
B. Adipose tissue
C. Brain
D. Liver
E. Spleen
20. Which pathway is activated by cortisol?
A. Glycolysis
B. Glycogenolysis
C. Lipolysis
D. Lipogenesis
E. Gluconeogenesis