Multiple Choice Question on Lipid and Lipoprotein Metabolism
1) A child was presented with diarrhea and failure to thrive. The clinical and biochemical investigation showed fat malabsorption, spinocerebellar degeneration, pigmented retinopathy, and acanthocytosis. develop. He had decreased night and color vision and followed by reductions in daytime visual acuity. The blood chemistry profile showed extremely low plasma cholesterol and triglyceride levels with no detectable chylomicrons VLDL, LDL, or apoB. The genetic analysis showed that the disease was inherited in an autosomal recessive manner.
Identify the probable cause from the following:
a) Mutation in the gene that codes for ApoB
b) Mutation in the gene that codes for MTP
c) Mutation in the gene that codes for ApoC-II
d) Mutation in the gene that codes for CEPT
a) Chylomicrons Identify the probable cause from the following:
a) Mutation in the gene that codes for ApoB
b) Mutation in the gene that codes for MTP
c) Mutation in the gene that codes for ApoC-II
d) Mutation in the gene that codes for CEPT
2) The biochemical analysis of plasma from a patient with pancreatitis showed hypertriglyceridemia with increased VLDL and chylomicrons. To further investigate, the patient was administered heparin intravenously and blood samples were collected to analyze the lipolytic activity in plasma. The test showed low LPL activity in post heparinized blood samples.
Identify the probable cause of the after an intravenous heparin injection increased VLDL and Chylomicrons
a) Deficiency of Apo B
b) Deficiency of Lipoprotein Lipase
c) Deficiency of LDL receptor
d) Deficiency of Apo A-I
3) The highest phospholipids content is found in …........................
b) VLDL
c) LDL
d) HDL
4) The class of lipoproteins that is protective against atherosclerosis is …...........................
a) Low-density of lipoproteins
b) Very low-density lipoproteins
c) High-density lipoproteins
d) Chylomicrons
5) Genetic deficiency of lipoprotein lipase cause hyperlipoproteinemia of the following type:
a) Type I
b) Type IIa
c) Type IIb
d) Type V
6) Activated lecithin cholesterol acyltransferase is essential for the conversion of ...
a) VLDL remnants into LDL
b) Nascent HDL into HDL
c) HDL2 into HDL3
d) HDL3 into HDL2
7) Zellweger’s syndrome is associated with abnormality of
a) Nonessential fatty acid metabolism
b) Essential fatty acid metabolism
c) cholesterol metabolism
d) Lipoprotein metabolism
8) Tangier disease is a disorder of lipoprotein metabolism. The phenotype corresponds to
a) Low level of VLDL
b) Low level of LDL
c) Low level of IDL
d) Low level of HDL
9) Although ketogenesis occurs in hepatocytes it cannot utilize ketone bodies. It is due to a deficiency of which of the following enzyme?
a) Thiokinase
b) Thiophorase
c) Thiolase
d) Thiolyase
10) Fatty acid oxidation is regulated by malonyl CoA. The malonyl CoA inhibits
a) The entry of fatty acid into the cell
b) Activation of fatty acid to fatty acyl CoA
c) Shuttling of fatty acyl CoA to mitochondria
d) Dehydrogenation of fatty acyl CoA to enoyl CoA
a) The entry of fatty acid into the cell
b) Activation of fatty acid to fatty acyl CoA
c) Shuttling of fatty acyl CoA to mitochondria
d) Dehydrogenation of fatty acyl CoA to enoyl CoA
11) Familial Hypercholesterolemia is a codominant genetic disorder caused by a mutation of the gene that encodes for:
a) Apolipoprotein E
b) Apolipoprotein B
c) LDL receptor
d) VLDL receptor
12) Which of the following statement is true regarding familial hypercholesterolemia?
a) In heterozygotes, the serum cholesterol level range from 275 to 500 mg/dL
b) Plasma triglycerides are generally elevated >300 mg/dL
c) Serum LDL-cholesterol is within the normal range
d) All of the above
13) Familial Hypertriglyceridemia is characterized by
a) Increased plasma VLDL and triglycerides (200-500 mg/dL)
b) Normal or mildly increased cholesterol level (<250 mg/dL)
c) Reduced plasma HDL level
d) All of the above
14) Chylomicron is a type of lipoprotein that transports triglycerides from the intestine to peripheral tissues.
Which of the following is an integral apolipoprotein present in a chylomicron?
a) Apo B100
b) Apo B48
c) Apo CII
d) ApoE
15) Which of the following is an integral apolipoprotein present in VLDL, IDL, and LDL?
a) Apo B100
b) Apo B48
c) Apo CII
d) ApoE
16) The lipoprotein lipase is present in the endothelial surfaces of adipose tissues in the heart and it is required for hydrolysis and release of triglycerides from chylomicrons.
Which of the apolipoprotein that is present in chylomicron serves as the activator of an enzyme lipoprotein lipase?
a) Apo B100
b) Apo B48
c) Apo CII
d) ApoE
17) Chylomicron remnants are rapidly taken by the liver in a process that requires
a) Apo B100
b) Apo B48
c) Apo CII
d) ApoE
18) HDL is a type of lipoprotein that is important for acquiring cholesterol from VLDL and chylomicrons.
Which of the following proteins are important for HDL function?
a) Apo A-I
b) Lecithin-Cholesterol Acyltransferase (LCAT)
c) Cholesteryl Ester Transport Protein
d) All of the Above
19) The clearance of LDL cholesterols in hepatocytes requires:
a) LDL receptor
b) Apo CII receptor
c) Scavenger receptor BI
d) None of the above
20) The HDL is taken up by the hepatocytes via.................................
a) LDL receptor
b) Apo CII receptor
c) Scavenger receptor BI
d) None of the above
Answers to Multiple Choice Question:
1- b) Mutation in the gene that codes for MTP
2- b) Deficiency of Lipoprotein Lipase
3-d) HDL4-c) High-density lipoproteins
5- b) Type IIa
6-d) HDL3 into HDL2
7-b) Essential fatty acid metabolism
8-d) Low level of HDL
9-b) Thiophorase
10-c) Shuttling of fatty acyl CoA to mitochondria
11-c) LDL receptor
12- a) In heterozygotes, the serum cholesterol level range from 275 to 500 mg/dL
13)-d) All of the above
14)-b) Apo B48
15)-a) Apo B100
16- c) ApoCII
17-d) Apo E
18-d) All of the Above
19-a) LDL receptor
20-c) Scavenger receptor BI
