`CARBOHYDRATE METABOLISM
1. Gluconeogenesis:
a) Is favoured when isulin concentration is high
b) Occurs in the liver during prolonged fasting
c) Allows skeletal muscle to produce glucose for export to blood for use by the
CNS
d) Is stimulated by high levels of glucose-6-phosphate
e) Uses Acetyl CoA as substrate
2. Glucose-6-phosphate dehydrogenase:
a) Is the key enzyme in glycogenesis
b) Is activated by high levels of NADP+
c) Catalyzes conversion G6P to fructose-6-phosphate
d) Is important in muscle during exercise
e) Not found in RBC's
3. In the TCA cycle:
a) 3 ATP's are produced by substrate-level phosphorylation
b) Oxygen is directly involved
c) All reactions are reversible
d) Succinyl CoA is the precursor for Heme synthesis
e) Oxaloacetate is converted to pyruvate
4. The following can be synthesized from glucose in the human body:
a) Ribose and lactose
b) Lactose and cellulose
c) Sucrose and ribulose
d) Cellulose and fructose
e) Fatty acid sucrose
5. Glucose-6-phosphate deficiency:
a) Is known as Von Gierke's disease
b) Is associated with hypoglycemia in the fed state
c) Inhibits the last step of glycogenolysis and gluconeogenesis in the liver
d) Is associated with hyperuricemia
e) B is the only wrong statement
6. In glycogenesis:
a) ATP is required
b) Phosphoglucomutase catalyses irreversible step
c) Glucose residues are added to the reducing end of glycogen
d) Glycogen synthase is the key enzyme
e) 2 ATP molecules are consumed
7. In galactosemia:
a) Treatment involves restriction of glucose in diet
b) The liver function can be seriously affected
c) Galactose is deposited in tissues
d) Galactose is readily converted to glucose
e) Galactosuria is the most serious manifestation
,8. Uncoupling of oxidative phosphorylation:
a) Decreases the oxygen consumption
b) Releases heat only
c) Occurs during hypoxia
d) Causes a buildup of NADH
e) Produces more ATP
9. The enzyme not involved in glycolyisis is:
a) Aldolase
b) Endolase
c) Pyruvate kinase
d) Phosphoglycerate mutase
e) Alpha phosphoglycerate dehydrogenase
10. Which of the following is not a glycolytic intermediate?d
a) Glucose-6-phosphate
b) Fructose-6-phosphate
c) Dihydroxyacetone phosphate
d) Pyruvate
e ) Glycerol-3-phosphate
11. Which site utilizes glucose as an energy source exclusively in all conditions:e
a) Brain
b) Muscle
c) Liver
d) Fat cell
e) Erythrocyte
12. The following agent interferes with oxidative phosphorylation:e
a) Cyanide inhibits NADH-dehydrogenase
b) Carbon monoxide inhibits Coenzyme Q
c) Rotenone enhances electron transfer
d) Oligomyein inhibits electron transfer
e) Dintrophenol uncouples phosphorylation from electron transfer
13. The following compounds are part of the pyruvate dehydrogenase complex:e
a) Thiamin diphosphate
b) Lipoamide
c) CoA
d) NAD+
e) All of the above
14. UDP-G:
a) Is derived from vitamin B1
b) Is a substrate for the enzyme glycogen phosphorylase
c) Is intermediate in glycerophospholipid synthesis
d) Is not required for normal galactose metabolism
e) Can be formed from UDP-Galactose
, 15. Glycogen phosphorylase:
a) Is a mitochondrial enzyme
b) Is activated by dephosphorylation
c) Acts by the same mechanism as intestinal amylase
d) Produces uridine diphosphate from glycogen
e) Produces glucose-1-phosphate
16. Fructose 2,6 bisphosphate:
a) Is a glycolytic intermediate
b) Activates phosphofructokinase 1
c) Is synthesized by phopshofuctokinase 1
d) Enhances fructose 1,6 bisphosphate
e) Level in the liver is increased by glucagon
17. Pyruvate carboxylase:
a) Converts acetyl CoA to pyruvate
b) Requires carnitine
c) Converts pyruvate to oxaloacetate
d) Is activated by high fructose 1,6 bisphosphate
e) Requires pyridoxal phosphate
18. In glycogen storage diseases:
a) Von Gierke's disease is type III
b) Hypoglycemia is the main feature of type V
c) Type II is associated with glucose 6 phosphatase deficiency
d) Type IV is called Andersen's disease
e) Hepatomegally is the main feature of all types
19. Which of the following statements about galactosemia is correct:
a) Treatment involves restriction of glucose in the diet
b) A deficiency of glucokinase is the major case
c) Is treated by elimination of galactose from the diet
d) Can be treated by restricting sucrose in the diet
e) Is inherited as autosomal dominant character
20. Glucose-6-phosphate dehydrogenase:
a) Is the key enzyme in glycogenesis
b) Deficiency can cause hemolytic anemia
c) Catalyses conversion of G6P to fructose-6-phosphate
d) Is important in muscles during exercise
e) Is not found in RBC's
21. Synthesis of glucose from pyruvate by gluconeogenesis in the liver:
a) Occurs exclusively in the cytosol
b) Is inhibited during prolonged fasting
c) Requires participation of biotin
d) Requires lactate as intermediate
e) Occurs exclusively in the mitochondrion
1. Gluconeogenesis:
a) Is favoured when isulin concentration is high
b) Occurs in the liver during prolonged fasting
c) Allows skeletal muscle to produce glucose for export to blood for use by the
CNS
d) Is stimulated by high levels of glucose-6-phosphate
e) Uses Acetyl CoA as substrate
2. Glucose-6-phosphate dehydrogenase:
a) Is the key enzyme in glycogenesis
b) Is activated by high levels of NADP+
c) Catalyzes conversion G6P to fructose-6-phosphate
d) Is important in muscle during exercise
e) Not found in RBC's
3. In the TCA cycle:
a) 3 ATP's are produced by substrate-level phosphorylation
b) Oxygen is directly involved
c) All reactions are reversible
d) Succinyl CoA is the precursor for Heme synthesis
e) Oxaloacetate is converted to pyruvate
4. The following can be synthesized from glucose in the human body:
a) Ribose and lactose
b) Lactose and cellulose
c) Sucrose and ribulose
d) Cellulose and fructose
e) Fatty acid sucrose
5. Glucose-6-phosphate deficiency:
a) Is known as Von Gierke's disease
b) Is associated with hypoglycemia in the fed state
c) Inhibits the last step of glycogenolysis and gluconeogenesis in the liver
d) Is associated with hyperuricemia
e) B is the only wrong statement
6. In glycogenesis:
a) ATP is required
b) Phosphoglucomutase catalyses irreversible step
c) Glucose residues are added to the reducing end of glycogen
d) Glycogen synthase is the key enzyme
e) 2 ATP molecules are consumed
7. In galactosemia:
a) Treatment involves restriction of glucose in diet
b) The liver function can be seriously affected
c) Galactose is deposited in tissues
d) Galactose is readily converted to glucose
e) Galactosuria is the most serious manifestation
,8. Uncoupling of oxidative phosphorylation:
a) Decreases the oxygen consumption
b) Releases heat only
c) Occurs during hypoxia
d) Causes a buildup of NADH
e) Produces more ATP
9. The enzyme not involved in glycolyisis is:
a) Aldolase
b) Endolase
c) Pyruvate kinase
d) Phosphoglycerate mutase
e) Alpha phosphoglycerate dehydrogenase
10. Which of the following is not a glycolytic intermediate?d
a) Glucose-6-phosphate
b) Fructose-6-phosphate
c) Dihydroxyacetone phosphate
d) Pyruvate
e ) Glycerol-3-phosphate
11. Which site utilizes glucose as an energy source exclusively in all conditions:e
a) Brain
b) Muscle
c) Liver
d) Fat cell
e) Erythrocyte
12. The following agent interferes with oxidative phosphorylation:e
a) Cyanide inhibits NADH-dehydrogenase
b) Carbon monoxide inhibits Coenzyme Q
c) Rotenone enhances electron transfer
d) Oligomyein inhibits electron transfer
e) Dintrophenol uncouples phosphorylation from electron transfer
13. The following compounds are part of the pyruvate dehydrogenase complex:e
a) Thiamin diphosphate
b) Lipoamide
c) CoA
d) NAD+
e) All of the above
14. UDP-G:
a) Is derived from vitamin B1
b) Is a substrate for the enzyme glycogen phosphorylase
c) Is intermediate in glycerophospholipid synthesis
d) Is not required for normal galactose metabolism
e) Can be formed from UDP-Galactose
, 15. Glycogen phosphorylase:
a) Is a mitochondrial enzyme
b) Is activated by dephosphorylation
c) Acts by the same mechanism as intestinal amylase
d) Produces uridine diphosphate from glycogen
e) Produces glucose-1-phosphate
16. Fructose 2,6 bisphosphate:
a) Is a glycolytic intermediate
b) Activates phosphofructokinase 1
c) Is synthesized by phopshofuctokinase 1
d) Enhances fructose 1,6 bisphosphate
e) Level in the liver is increased by glucagon
17. Pyruvate carboxylase:
a) Converts acetyl CoA to pyruvate
b) Requires carnitine
c) Converts pyruvate to oxaloacetate
d) Is activated by high fructose 1,6 bisphosphate
e) Requires pyridoxal phosphate
18. In glycogen storage diseases:
a) Von Gierke's disease is type III
b) Hypoglycemia is the main feature of type V
c) Type II is associated with glucose 6 phosphatase deficiency
d) Type IV is called Andersen's disease
e) Hepatomegally is the main feature of all types
19. Which of the following statements about galactosemia is correct:
a) Treatment involves restriction of glucose in the diet
b) A deficiency of glucokinase is the major case
c) Is treated by elimination of galactose from the diet
d) Can be treated by restricting sucrose in the diet
e) Is inherited as autosomal dominant character
20. Glucose-6-phosphate dehydrogenase:
a) Is the key enzyme in glycogenesis
b) Deficiency can cause hemolytic anemia
c) Catalyses conversion of G6P to fructose-6-phosphate
d) Is important in muscles during exercise
e) Is not found in RBC's
21. Synthesis of glucose from pyruvate by gluconeogenesis in the liver:
a) Occurs exclusively in the cytosol
b) Is inhibited during prolonged fasting
c) Requires participation of biotin
d) Requires lactate as intermediate
e) Occurs exclusively in the mitochondrion
