UNE Medical Biochemistry Final Exam Review
Questions And Answers
Under fasting conditions (ratio of insulin: glucagon <1), elevated glucagon will activate
which of the following enzymes? ✅hormone sensitive lipase
Ketonuria, hypoglycemia, and severe acidosis are prime diagnostic indicators of the
presentation of type 1 diabetic ketoacidosis. Which of the following compounds are
"ketone bodies" that would be elevated in serum of urine of a patient in this condition?
✅D-3-hydroxybutyrate and acetoacetate
What is the purpose of cholesterol esterification within the cell? (the conversion of
cholesterol to cholesteryl ester)
a. this modification makes cholesterol more soluble in the plasma membrane
b. this modification does not change the chemical properties of cholesterol
c. esterification is the first step in the synthesis of cortisol
d. esterification traps cholesterol in the cell ✅esterification traps cholesterol in the cell
An individual goes to bed around 8 pm and doesn't wake up until 9 am the next
morning. During this time, which of the following is the primary oxidizable substrate in
the skeletal muscle?
a. free fatty acids
b. glycogen
c. amino acids
d. lactate ✅free fatty acids
A 22-year-old woman engaging in a political protest goes on a hunger strike on a
prominent corner in a city park. She refuses all offers of food for except for water
through the first 2 weeks. Under these conditions there is a decreased reliance on
which of the following pathways for fuel?
a. β-oxidation
b. ketogenesis
c. gluconeogenesis
d. lipolysis ✅gluconeogenesis
In reverse cholesterol transport HDL interacts with the ABCA1 transporter to move
cholesterol from the cell to the HDL. This also requires the activity of which of the
following enzyme?
a. lipoprotein lipase
b. cholesteryl ester transfer protein (CETP)
c. lecithin cholesterol acyltransferase (LCAT)
d. LDL receptor ✅lecithin cholesterol acyltransferase (LCAT)
, A 16-year-old woman presents to her primary care physician for a follow up visit. At her
initial visit, 3 months ago, her serum cholesterol was 255 mg/dL (above normal). She
finds this very disappointing as she started a strict dietary regime reducing all fats and
cholesterol, replacing them with a high carbohydrate diet. You tell her that high
carbohydrate diets can increase serum triglyceride levels in some individuals. This can
be attributed in an increase in the synthesis of which of the following lipoproteins?
a. chylomicrons
b. VLDL
c. IDL
d. HDL
e. LDL ✅VLDL
a 5-year-old presents to her primary care physician. Her mother is concerned due to
persistent diarrhea which is worse when eating fatty foods. The child also has some
clinical signs of a deficiency in fat-soluble vitamins. Based on this information the child
likely has a deficiency in the ability to synthesize which of the following lipoproteins?
a. chylomicrons
b. VLDLs
c. LDLs
d. HDLs ✅chylomicrons
The interaction of chylomicorns with lipoprotein lipase is stimulated by which of the
following Apo proteins?
a. ApoB 100
b. Apo B 48
c. Apo C II
d. Apo E ✅Apo C II
A defect in the thioesterase subunit of fatty acid synthase would impair which of the
following activities of the enzyme complex?
a. liberation of newly assembled palmitate from the enzyme
b. priming of the enzyme iwth acetyl-CoA
c. Liberation of Co2 from 3-ketoacyl synthase
d. binding of malonyl-CoA to an SH group ✅liberation of newly assembled palmitate
from the enzyme
An increase in the ratio of insulin to glucagon leads to which of the following metabolic
shifts?
a. acetyl-CoA carboxylase will become dephosphorylated and active
b. cytosolic levels of malonyl-CoA will decrease
c. hormone sensitive lipase will become dephosphorylated and active
d. VLDL synthesis will decrease ✅acetyl-CoA carboxylase will become
dephosphorylated and active
HDL particles interact with VLDL particles to exchange cholesterol ester for
triacylglyerols. Which of the following enzymes is responsible for this process?
Questions And Answers
Under fasting conditions (ratio of insulin: glucagon <1), elevated glucagon will activate
which of the following enzymes? ✅hormone sensitive lipase
Ketonuria, hypoglycemia, and severe acidosis are prime diagnostic indicators of the
presentation of type 1 diabetic ketoacidosis. Which of the following compounds are
"ketone bodies" that would be elevated in serum of urine of a patient in this condition?
✅D-3-hydroxybutyrate and acetoacetate
What is the purpose of cholesterol esterification within the cell? (the conversion of
cholesterol to cholesteryl ester)
a. this modification makes cholesterol more soluble in the plasma membrane
b. this modification does not change the chemical properties of cholesterol
c. esterification is the first step in the synthesis of cortisol
d. esterification traps cholesterol in the cell ✅esterification traps cholesterol in the cell
An individual goes to bed around 8 pm and doesn't wake up until 9 am the next
morning. During this time, which of the following is the primary oxidizable substrate in
the skeletal muscle?
a. free fatty acids
b. glycogen
c. amino acids
d. lactate ✅free fatty acids
A 22-year-old woman engaging in a political protest goes on a hunger strike on a
prominent corner in a city park. She refuses all offers of food for except for water
through the first 2 weeks. Under these conditions there is a decreased reliance on
which of the following pathways for fuel?
a. β-oxidation
b. ketogenesis
c. gluconeogenesis
d. lipolysis ✅gluconeogenesis
In reverse cholesterol transport HDL interacts with the ABCA1 transporter to move
cholesterol from the cell to the HDL. This also requires the activity of which of the
following enzyme?
a. lipoprotein lipase
b. cholesteryl ester transfer protein (CETP)
c. lecithin cholesterol acyltransferase (LCAT)
d. LDL receptor ✅lecithin cholesterol acyltransferase (LCAT)
, A 16-year-old woman presents to her primary care physician for a follow up visit. At her
initial visit, 3 months ago, her serum cholesterol was 255 mg/dL (above normal). She
finds this very disappointing as she started a strict dietary regime reducing all fats and
cholesterol, replacing them with a high carbohydrate diet. You tell her that high
carbohydrate diets can increase serum triglyceride levels in some individuals. This can
be attributed in an increase in the synthesis of which of the following lipoproteins?
a. chylomicrons
b. VLDL
c. IDL
d. HDL
e. LDL ✅VLDL
a 5-year-old presents to her primary care physician. Her mother is concerned due to
persistent diarrhea which is worse when eating fatty foods. The child also has some
clinical signs of a deficiency in fat-soluble vitamins. Based on this information the child
likely has a deficiency in the ability to synthesize which of the following lipoproteins?
a. chylomicrons
b. VLDLs
c. LDLs
d. HDLs ✅chylomicrons
The interaction of chylomicorns with lipoprotein lipase is stimulated by which of the
following Apo proteins?
a. ApoB 100
b. Apo B 48
c. Apo C II
d. Apo E ✅Apo C II
A defect in the thioesterase subunit of fatty acid synthase would impair which of the
following activities of the enzyme complex?
a. liberation of newly assembled palmitate from the enzyme
b. priming of the enzyme iwth acetyl-CoA
c. Liberation of Co2 from 3-ketoacyl synthase
d. binding of malonyl-CoA to an SH group ✅liberation of newly assembled palmitate
from the enzyme
An increase in the ratio of insulin to glucagon leads to which of the following metabolic
shifts?
a. acetyl-CoA carboxylase will become dephosphorylated and active
b. cytosolic levels of malonyl-CoA will decrease
c. hormone sensitive lipase will become dephosphorylated and active
d. VLDL synthesis will decrease ✅acetyl-CoA carboxylase will become
dephosphorylated and active
HDL particles interact with VLDL particles to exchange cholesterol ester for
triacylglyerols. Which of the following enzymes is responsible for this process?
