Quiz 1 Flashcards
A 40-year old woman with a history of type 2 diabetes mellitus visits her physician. Insulin was added to her therapeutic regimen a few months prior and her hemoglobin A1c has decreased from 8.3% to 7.1%. Which of the following metabolic pathway changes in the liver best explains the decrease in hemoglobin A1c in response to insulin?
a) Decreased oxidation of glucose
b) Increased synthesis of glycogen
c) Increased oxidation of fatty acids
d) Decreased synthesis of ketone bodies
b) Increased synthesis of glycogen
During anaerobic exercise, the NADH produced by glycolytic enzymes in the skeletal muscles is reoxidized primarily during which metabolic process?
a) Synthesis of beta-hydroxybutyrate from acetoacetate
b) Synthesis of glucose from glucose-6-phosphate
c) Synthesis of acetyl CoA from pyruvate
d) Synthesis of lactate from pyruvate
d) Synthesis of lactate from pyruvate
A 62 year old man presents to his physician reporting episodes of chest pain with exertion that are relieved with rest. The patient subsequently undergoes an exercise stress test to further investigate the cause of the chest pain. During the test, which of the following processes was most likely increased in this patient’s skeletal muscles?
a) Cleavage of glycosidic bonds
b) Autophosphorylation of insulin receptors
c) Activation of glucagon receptors
d) Synthesis of ketone bodies
a) Cleavage of glycosidic bonds
A 10 year old boy is brought to the emergency department by his family because of sudden onset abdominal pain that started two hours ago. They mention that he had dark urine earlier in the day. The patient’s family also report that he was recently treated with a medication a few days ago to treat a urinary tract infection. Further laboratory studies determine that the cause of the patient’s clinical presentation is a deficiency of an enzyme found in the cells that contain hemoglobin and carry oxygen to the tissues. Which of the following pathways most likely includes this enzyme?
a) Pentose phosphate shunt
b) Glycogenolysis
c) Gluconeogenesis
d) Fatty acid oxidation
a) Pentose phosphate shunt
Set point theory in the regulation of energy balance predicts that homeostatic processes will try to protect existing energy stores, even if the stores are high. If an obese person loses 15% of their body weight over several months, this theory predicts that which
process is most likely to be increased compared to when this person was at their original weight?
a) Energy expenditure at rest
b) Anorexigenic signaling
c) Thermic effect of food
d) Relative activity of POMC neurons compared to NPY neurons in the hypothalamus
e) Orexigenic signaling
e) Orexigenic signaling
A new drug is being studied for adverse effects in a Phase 1 clinical trial. The trial is stopped early because subjects who received the drug had an increased risk of excessive triglyceride storage in hepatocytes (fatty liver disease). The drug increases a metabolic pathway intermediate that inhibits a transporter in the inner mitochondrial membrane. Which intermediate is increased and what metabolic pathway is affected?
a) Acetoacetate, a product of ketogenesis
b) Malonyl CoA, the product of the first step of fatty acid synthesis
c) Acyl CoA, a substrate of triglyceride synthesis
d) HMG CoA, a substrate of the rate-limiting step of cholesterol synthesis
b) Malonyl CoA, the product of the first step of fatty acid synthesis
Which of the following correctly predicts the relative enzyme activities in the three 24-year-old adults. One ate a mixed meal two hours ago (post-prandial) one has fasted for 7 days, and one has developed severe diabetic ketoacidosis after 24 hours without insulin?
a) Mitochondrial synthesis of HMG CoA is highest in the fasting individual
b) Adipose lipolysis by hormone sensitive lipase is highest in the individual with DKA
c) Ketolysis in the brain is highest in the individual with DKA
d) Cytosolic synthesis of HMG CoA is highest in the fasting individual
b) Adipose lipolysis by hormone sensitive lipase is highest in the individual with DKA
During the post-meal period, increased hepatic fatty acid synthesis most directly increases the serum level of which lipoprotein?
a) Low density lipoproteins (LDL)
b) High density lipoproteins (HDL)
c) Very low density lipoproteins (VLDL)
d) Chylomicrons
c) Very low density lipoproteins (VLDL)
An increased level of what process is most significant in the development of foam cells in arterial walls as present in the model during lecture?
a) Modified apoB48-containing lipoproteins activating endothelial cells
b) Movement of monocytes in the connective tissue to become macrophages
c) Movement of ApoA1-containing lipoproteins into the connective tissue of the intima
d) Cholesterol ester accumulation in macrophages due to native (unmodified) LDL uptake through highly expressed LDL R’s
b) Movement of monocytes in the connective tissue to become macrophages
A 49 year old woman is started on simvastatin to lower her LDL-C. Which of the following is a possible adverse effect she may experience?
a) Hyperuricemia
b) Lactic acidosis
c) Myalgia
d) Gallstones
c) Myalgia
You are treating a 21 year old female with type 2 diabetes since the age of 13. She is currently taking insulin degludec (basal) 12 units daily and insulin lispro (bolus) 4 units with each meal. She notices that sometimes after lunch, she gets sweaty, shaking, and has racing heart beats. She checks her glucose during these symptoms and it is in the range of 50-68 mg/dL. She has these episodes 3-4 times weekly after lunch and never after other meals. What would you recommend?
a) Decrease insulin lispro (bolus) to 3 units before breakfast
b) Do not change insulin doses, hypoglycemia episodes are infrequent
c) Decrease insulin lispro (bolus) to 3 units before lunch
d) Decrease insulin degludec (basal) to 10 units daily
e) Decease insulin lispro (bolus) to 3 units with all meals
Decrease insulin lispro (bolus) to 3 units before lunch
Each of the following five patients was diagnosed with diabetes (type 1 or type 2) > 5 years ago and is receiving the listed therapy. Which answer best predicts the change in serum C-peptide in each of the five patients?
No change, increase, increase, no change, no change
Which of the following best describes the relative activity of biosynthetic pathways in liver cells in the two hours following a carbohydrate-rich meal?
Increase, decrease, increase, decrease, increase
A 37 year old male presents with hypoglycemia. He was in his usual state of health until one month ago, when he started having recurrent episodes of sweating, palpitations, and hunger. These episodes occur 1-3 times daily at random times. Symptoms resolve when with
drinking juice. He is the caretaker for his grandmother who has type 2 diabetes. He used her glucometer to check his fingerstick glucose during these episodes and glucose ranged from 48 to 69 mg/dL. You admit him for 72 hour fast. Three hours into the fast, he has a fingerstick glucose of 40 mg/dL, and labs are sent with the following results:
Plasma glucose: 42 mg/dL
Insulin: High
C-peptide: Low
Beta hydroxybutyrate: Low
Response to glucagon: Rise in glucose >25 mg/dL
What is the next best step in evaluation of this patient?
Ask pt if he’s been taking his grandmother’s insulin
