KYCOM 2020-BLOCK 2 BIOCHEM BRS BOOK QUESTIONS AND
ANSWERS WITH VERIFIED SOLUTIONS
transfer glucose from UDP-glucose to the nonreducing end of a glycogen primer
A newborn is found to have fasting hypoglycemia. The nursery staff begins overnight
feeds by nasogastric tube because they find that the child has consistently low blood
sugars. A liver biopsy and molecular studies demonstrate an absence of glycogen
synthase. The normal function of this enzyme is to do what?
loss of a lysosomal glucosidase activity
A newborn is experiencing failure to thrive. On physical exam, organomegaly is
appreciated owing to accumulation of glycogen in the lysosomes of several organs,
including the heart, muscle, and liver. You diagnose the condition as Pompe disease.
What is the biochemical deficit that is seen in this disorder?
pyruvate kinase
a 2nd year medical student decides to do research in a nutrition lab that is studying the
effects of caffeine on cellular metabolism. Caffeine inhibits cAMP phosphodiesterase. If
caffeine were added to liver cells, in the presence of glucagon, which of the following
enzymes would be phosphorylated and inactivated?
Insulin
a 28yo professional cyclist has been training for an opportunity to race in the Tour de
France. His coach strongly suggests that he consume carbs after each of his workouts
, to ensure that his muscle glycogen storage can endure the 28-day race. The activity of
muscle glycogen synthase in resting muscles is increased by the action of what?
Amylo-1,6-glucosidase (aplha-glucosidase)
a patient had large deposits of liver glycogen, which, after an overnight fast, contained
shorter than normal branches. A defective form of what could cause this abnormality
Dietary would give 1 less mole of ATP/glucose
A sprinter is trying to optimize his performance. He has calculated that, even under
anaerobic conditions, his glycogen stores will supply him with enough energy to last the
race. What would the energy difference be between using glucose from a dieatary
source versus relying solely on glucose from glycogen stores as fuel for his race?
glycogen phosphorylase kinase
A 32yo woman receives anesthesia in preparation for a laparascopic cholecystectomy.
The anesthesiologist notices a subtle twitch of the masseter muscle in the jaw, followed
by sinus tachycardia and an increase of the end-expiratory CO2. He immediately
recognizes the early signs of malignant hyperthermia and administers dantrolene.
Dantrolene is a muscle relaxant that acts specifically on skeletal muscle by interfering
with the release of calcium from the sarcoplasmic reticulum. What enzyme would be
affected by this action?
lactose
A 14 day old breast fed neonate fails to gain weight during infancy. Although concerned,
the mother continues to breast-feed and wait. The infant subsequently develops
cataracts, an enlarged dliver, and mental retardation. Urinalysis is significant for high
ANSWERS WITH VERIFIED SOLUTIONS
transfer glucose from UDP-glucose to the nonreducing end of a glycogen primer
A newborn is found to have fasting hypoglycemia. The nursery staff begins overnight
feeds by nasogastric tube because they find that the child has consistently low blood
sugars. A liver biopsy and molecular studies demonstrate an absence of glycogen
synthase. The normal function of this enzyme is to do what?
loss of a lysosomal glucosidase activity
A newborn is experiencing failure to thrive. On physical exam, organomegaly is
appreciated owing to accumulation of glycogen in the lysosomes of several organs,
including the heart, muscle, and liver. You diagnose the condition as Pompe disease.
What is the biochemical deficit that is seen in this disorder?
pyruvate kinase
a 2nd year medical student decides to do research in a nutrition lab that is studying the
effects of caffeine on cellular metabolism. Caffeine inhibits cAMP phosphodiesterase. If
caffeine were added to liver cells, in the presence of glucagon, which of the following
enzymes would be phosphorylated and inactivated?
Insulin
a 28yo professional cyclist has been training for an opportunity to race in the Tour de
France. His coach strongly suggests that he consume carbs after each of his workouts
, to ensure that his muscle glycogen storage can endure the 28-day race. The activity of
muscle glycogen synthase in resting muscles is increased by the action of what?
Amylo-1,6-glucosidase (aplha-glucosidase)
a patient had large deposits of liver glycogen, which, after an overnight fast, contained
shorter than normal branches. A defective form of what could cause this abnormality
Dietary would give 1 less mole of ATP/glucose
A sprinter is trying to optimize his performance. He has calculated that, even under
anaerobic conditions, his glycogen stores will supply him with enough energy to last the
race. What would the energy difference be between using glucose from a dieatary
source versus relying solely on glucose from glycogen stores as fuel for his race?
glycogen phosphorylase kinase
A 32yo woman receives anesthesia in preparation for a laparascopic cholecystectomy.
The anesthesiologist notices a subtle twitch of the masseter muscle in the jaw, followed
by sinus tachycardia and an increase of the end-expiratory CO2. He immediately
recognizes the early signs of malignant hyperthermia and administers dantrolene.
Dantrolene is a muscle relaxant that acts specifically on skeletal muscle by interfering
with the release of calcium from the sarcoplasmic reticulum. What enzyme would be
affected by this action?
lactose
A 14 day old breast fed neonate fails to gain weight during infancy. Although concerned,
the mother continues to breast-feed and wait. The infant subsequently develops
cataracts, an enlarged dliver, and mental retardation. Urinalysis is significant for high
