BCHEM LE6 (2024) Flashcards
- Transporter of lipid that is lowest in density but largest in size. It contains the highest percentage of lipid and the smallest of protein.
A. Chylomicron
B. VLDL
C. LDL
D. HDL
Chylomicron
- Which of the following is true about plasma lipoproteins?
A. They are held together by covalent bonds.
B. They are composed of a neutral lipid core surrounded by esterified cholesterol.
C. They have varied protein to lipid ratio.
D. The principal lipid carried by lipoprotein particles are chylomicrons.
They have varied protein to lipid ratio.
- This apoprotein is found in the particles released by the intestinal mucosal cells called “nascent” chylomicrons.
A. Apo CII
B. Apo B48
C. Apo B100
D. Apo C
Apo B48
- This apoprotein is found in the particles released by the intestinal mucosal cells called “nascent” chylomicrons.
A. Apo CII
B. Apo B48
C. Apo B100
D. Apo C
Apo B48
- Which of the following proteins are the major carriers of triacylglycerols?
A. VLDL and LDL
B. Chylomicrons and VLDL
C. Chylomicrons and LDL
D. VLDL and HDL
Chylomicrons and VLDL
- As the lipid-to-protein ratio decreases, particles become smaller and more dense in the following order:
A. Chylomicron > HDL > VLDL > LDL
B. Chylomicron > VLDL > LDL > HDL
C. HDL > LDL > VLDL > Chylomicron
D. HDL > LDL > VLDL > Chylomicron
Chylomicron > VLDL > LDL > HDL
- Which statement is correct?
A. A marked decrease in triacylglycerol produces turbidity in plasma.
B. Because chylomicrons are the most dense, they form a supranate.
C. Increased turbidity can result from an increase in chylomicrons or VLDL.
D. Plasma lipoproteins transport the highly-soluble lipids.
Increased turbidity can result from an increase in chylomicrons or VLDL.
- This apolipoprotein antagonizes ApoE and is known to inhibit lipoprotein lipids.
A. ApoB
B. ApoC-I
C. ApoC-III
D. ApoC-II
ApoC-III
- In the exogenous pathway, this apoprotein activates lipoprotein lipase which catalyzes the hydrolysis of triacylglycerols.
A. Apo E
B. Apo C
C. Apo B48
D. Apo A8
Apo C
- Site of action of hormone sensitive lipase that degrades stored triacylglycerols activated by cAMP-dependent protein kinase:
A. Stomach
B. Pancreas
C. Adipocytes
D. Liver
Adipocytes
- They are composed predominantly of triacylglycerol and they carry this lipid to the peripheral tissues from the liver:
A. Chylomicron
B. VLDL
C. LDL
D. HDL
VLDL
- Its primary function is to provide cholesterol to the peripheral tissues by depositing cholesterol in the membranes of the cells.
A. Chylomicron
B. VLDL
C. LDL
D. HDL
LDL
- Nascent triglyceride-rich very low density lipoproteins are secreted from the:
A. Intestinal mucosal cells
B. Liver
C. Stomach
D. Pancreas
Liver
- Which of the following is true about metabolism of low density lipoproteins?
A. LDL receptors are positively charged glycoprotein molecules that are clustered in pits on cell membranes.
B. After binding, the LDL undergo a process called exocytosis.
C. The pH of the contents of the endosomes increases allowing separation of the LDL from its receptor where receptors migrate to one side of the endosome and the LDLS stay free within the lumen of the vesicle.
D. The receptors can be recycled whereas the lipoprotein remnants in the vesicles are degraded by lysosomal enzymes releasing cholesterol, fatty acids, amino acids and phospholipids.
The receptors can be recycled whereas the lipoprotein remnants in the vesicles are degraded by lysosomal enzymes releasing cholesterol, fatty acids, amino acids and phospholipids.
- The initiating step in the modification of ApoB involves which process?
A. Peroxidation of polyunsaturated fatty acids in the LDL lipids.
B. Regulation of modified LDL taken up by macrophages.
C. Acetylation of apolipoprotein B.
D. Oxidation of circulating macrophages with low levels of scavenger receptor activity.
Peroxidation of polyunsaturated fatty acids in the LDL lipids.
- Which of the following is not correct about HDL’s?
A. HDL particles are synthesized in the liver and are released into the bloodstream by endocytosis.
B. Newly secreted HDL are disc-shaped particles containing predominantly unesterified cholesterol, phopholipid and a number of lipoproteins.
C. They are excellent acceptors of unesterified cholesterol from the surface of cell membranes and from other circulating lipoproteins.
D. The only mechanism for removing cholesteryl ester from HDL in the plasma is through transfer to VLDL.
HDL particles are synthesized in the liver and are released into the bloodstream by endocytosis.
- This transferes cholesterol from HDL to VLDL and triacylglycerols from VLDL to HDL.
A. Lipoprotein lipase (LPL)
B. Cholesteryl ester transfer protein (CETP)
C. Hepatic lipase (HPL)
D. CURL
Cholesteryl ester transfer protein (CETP)
- Familial hypercholesterolemia is usually secondary to a deficiency in:
A. ApoCII
B. ApoB48
C. ApoB100
D. ApoCIII
ApoCII
- Which of the following comprises metabolic syndrome?
A. Elevated HDL, hypertension, elevated blood sugar, obesity
B. Elevated LDL, hypertension, elevated blood sugar, obesity
C. Elevated HDL, hypertension, elevated triglycerides, obesity
D. Elevated LDL, hypotension, elevated blood sugar, obesity
Elevated LDL, hypertension, elevated blood sugar, obesity
- Which functions of the apoproteins refer to solubilisation of lipids?
A. Enzymatic
B. Esterification
C. Structural
D. Recognition
Structural
- GT, a 3-month old female, was brought in to your clinic for consult. She was born via home delivery from Cagayan. On work-up, she had abnormal red blood cell morphology and neurologic symptoms. This can be a lipoprotein abnormality secondary to:
A. Absence of normal LDL
B. Absence of normal HDL
C. Lack of ApoC proteins
D. Lack of ApoA proteins
Absence of normal LDL
- They are excellent acceptors of unesterified cholesterol, both from the surface of the cell membranes and from other circulating lipoproteins.
A. Chylomicron
B. VLDL
C. LDL
D. HDL
HDL
- Activates lecithin cholesterol acyltransferase (LCAT), which esterifies tissue cholesterol picked up by HDL.
A. ApoB
B. ApoC-I
C. ApoC-II
D. ApoA-1
ApoA-1
- They are endocytosed by target cells with receptors and degraded, releasing cholesterol, which decreases further uptake of cholesterol.
A. Chylomicron
B. VLDL
C. LDL
D. HDL
LDL
- Which of the following lipids is NOT part of a lipoprotein?
A. Phospholipids
B. Triacylglycerols
C. Esterified cholesterol
D. Unesterified cholesterol
Esterified cholesterol
- Which of the following is abundantly present in the white matter of the brain?
A. Galactocerebroside
B. Glucocerebrosides
C. Triacylglycerols
D. Gangliosides
Galactocerebroside
- Which of the following is NOT a glycerophospholipid?
A. Cardiolipin
B. Plasmalogen
C. Lecithin
D. Sphingomyelin
Sphingomyelin
- Which of the following phospholipids acts as a precursor for the generation of inositides?
A. Phosphatidyl choline
B. Phosphatidyl inositol
C. Phosphatidyl serine
D. Phosphatidyl ethanolamine
Phosphatidyl inositol
- Which type of special lipid serves as the receptor for choleragen in the intestinal cells?
A. GM2 ganglioside
B. GM1 ganglioside
C. Sphingomyelin
D. Galactocerebroside
GM1 ganglioside
- Which of the following is an intermediate both for the synthesis of phospholipids and triacylglycerols?
A. Diacylglycerol
B. Cholesterol
C. Choline
D. Inositol
Diacylglycerol
- A 3-year old child was brought to the medical center and found to have hepatosplenomegaly and mental retardation. Biopsy reveals accumulation of sphingomyelin. What is the nature of the disease?
A. Gaucher’s
B. Niemann Pick’s
C. Krabbe’s
D. Tay Sach’s
Niemann Pick’s
- Among the following special lipids, which is a glycerophospholipid?
A. Cardiolipin
B. Galactosyl ceramide
C. GM2
D. Sphingomyelin
Cardiolipin
- The enzymes that is deficient in Niemann Pick’s disease?
A. Glucocerebrosidase
B. Hexosaminidase A
C. Sphingomyelinase
D. b-galactocerebrosidase
Sphingomyelinase
- Among the following special lipids, which is a sphingophospholipid?
A. Cardiolipin
B. Plasmalogen
C. Lecithin
D. Sphingomyelin
Sphingomyelin
- Which of the following phospholipids acts as a lipotropic agent?
A. Phosphatidyl choline
B. Phosphatidyl inositol
C. Phosphatidyl serine
D. Cardiolipin
Phosphatidyl choline
- What are the components of a galactocerebroside?
A. Sphingosine + fatty acid + galactose
B. Glycerol + fatty acids + phosphoric acid + galactose
C. Glycerol + fatty acids + phosphoric acid + nitrogenous base + galactose
D. Sphingosine + fatty acid + phosphoric acid + galactose
Sphingosine + fatty acid + galactose
- What is the major component of the lung surfactant?
A. Dipalmitoyllecithin
B. Dipalmitoylphospatidyl serine
C. Dipalmitoylcephalin
D. Dipalmitoylphosphatidyl inositol
Dipalmitoyllecithin
- Ethanolamine is the nitrogenous base of which phospholipid?
A. Cardiolipin
B. Phosphatidyl inositol
C. Lecithin
D. Cephalin
Cephalin
- What is the significance of L:S ratio determination of amniotic fluid in a pregnant female?
A. Fetal heart rate
B. Fetal lung maturity
C. Fetal head size
D. Expected date of delivery
Fetal lung maturity
- What are the components of ceramide?
A. Sphingosine + fatty acid
B. Glycerol + fatty acid + phosphoric acid
C. Glycerol + fatty acid + phosphoric acid + nitrogenous base
D. Sphingosine + fatty acids + phosphoric acid
Sphingosine + fatty acid