Lipids Flashcards
Fatty acids:which is false?
A.only a relatively small amount exists in the free or unesterified form in plasma
B.most are non-covalently bound to albumin
C. are found as a constituent of triglycerides or phospholipids
D.are covalently attached to the glycerol backbone of triglycerides and phospholipids by a peptide bond
D
Ester dapat
most common phospholipid found on lipoproteins & cell membranes
phosphatidylcholine
Which is false?
A. phospholipids are only synthesised in the liver
B. Cholesterol esters are neutral lipids
C. phospholipids are amphipathic
D. size is directly proportional to apolipoprotein’s relative lipid content
A
all cytosolic cell compartments :)
False about dietary phytosterols’ effect
A. ↓ plasma total cholesterol
B. ↓ LDL cholesterol
C. ↓ HDL cholesterol
C
The liver does not convert cholesterol into: A.cholic acid B.glucocorticoids C.vitamin B D. NOTA
C
vitamin D3 dapat
enumerate 2 basis of classification for lipoproteins
Electrophoretic mobility
Buoyant density
Which is false? A.Chylomicron – most (-) charge B. β-lipoprotein – for VLDL C.Pre β-lipoprotein – for LDL D.α-lipoprotein – for chylomicron
D - for HDL dapat
Which is false about chylomicrons?
A.Largest and the least dense of the lipoproteins
B.scatter light, hence turbid/milky appearance of postprandial plasma
C.produced by the intestine where they are packaged with dietary lipids and apo B-100
D.in-charge of delivery of dietary lipids to hepatic and peripheral cells
C. apo B-48 dapat
False about VLDL
A.Produced by the liver
B.Contains apo B-100 – main apolipoprotein
C.form a creamy top layer like chylomicrons
D.major carriers of endogenous (from
synthesis of the body) triglycerides
C. They do not form a creamy top layer
high levels of intermediate-density lipoproteins are found in patients with familial hyperlipoproteinemia. why?x
Due to an abnormal form of apo E that delays the clearance of IDL; Individuals affected have significant risk for peripheral vascular disease (PVD) and coronary artery disease (CAD)
False about LDL
A. Large LDL particles have beenshown to be more proatherogenic and may be a better marker for CHD risk
B. Readily taken up by cells via the LDL receptor in the liverand peripheral cells
C. LDL particles have been separated through density ultracentrifugation or gradient gel electrophoresis
D. smaller particles are denser and have relatively more
triglyceride than cholesteryl esters
A
Smaller dapat
macrophages that take up too much lipid - what happens to them?
Filled with intracellular lipid drops o Turned into foam cells
predominant cell type of fatty streaks
early precursor of atherosclerotic plaques
false about lipoprotein (A)
A. Are LDL-like particles that contain one molecule of apo(a) linked to apo B-100 by a single ester bond
B. Lp(a) is larger than LDL and has a higher lipid content
and a slightly lower density
C. postulated to be removed @ kidneys
D. Have a high level of homology with plasminogen, a precursor of plasmin that promotes clot lysis via fibrin
cleavage
A
sulfide dapat
false about HDL
A.Transport cholesterol to liver for metabolism
B.The smallest and most dense lipoprotein particle
C.Is synthesized by liver only
C
liver and intestine dapat
most active form of HDL in removing excess cholesterol from peripheral cells
A. Discoidal
B. Spherical
C. equal lang
A
abnormal lipoprotein present in patients with biliary cirrhosis or cholestasis and in patients with mutations in lecithin:cholesterolacyltransferase (LCAT), the enzyme that esterifies cholesterol
lipoprotein X
False about lipoprotein X
A.Is different from other lipoproteins in the endogenous pathway due to the lack of apoB-48
B.Phospholipids and non-esterified cholesterol are the lipid components
C.albumin and apoC are the main protein components D.mainly removed by the reticuloendothelial system of the liver and the spleen
A
apo B-100 dapat
false abt apolipoproteins
A.Are primarily located on the bottom of lipoprotein particles
B.Help maintain the structural integrity of lipoproteins
C.Also serve as ligands for cell receptors and as activators and inhibitors of the various enzymes that modify
lipoprotein particles
A
surface dapat
apolipoproteins contain a structural motif called an ___which accounts for the ability of these proteins to bind to lipids
amphipathic helix
identify
– The major protein of HDL
– Frequently used as a measure of the amount of the
antiatherogenic HDL present in plasma
apo A-1
differentiate apo B-100 fr Apo B-48
Apo B-100: LDL, VLDL
Apo B-48: chylomicrons
fill in the blanks
1. Patients who are homozygous for the __
isoform are at an increased risk for developing type
III hyperlipoproteinemia.
2. individuals with the __ isoform have been
shown to have an increased risk of developing
Alzheimer’s disease
- apo E2
2. apo E4
These 3 processes depend on apo B–containing lipoprotein particles. These three pathways are critical in the transport to peripheral cells of fatty acids generated during the lipolysis of triglycerides and cholesteryl esters
Their net result is also the net delivery of cholesterol to peripheral cells,
identify the 3 processes
LIPID ABSORPTION PATHWAY, EXOGENOUS PATHWAY, AND ENDOGENOUS PATHWAY
false about reverse cholesterol transport pathway
A.principal way that peripheral cells maintain their cholesterol equilibrium
B.is mediated by chylomicrons
C. Excess cholesterol from peripheral cells is transported
back to the liver
D.excess cholesterol may be excreted into the bile as free cholesterol or after being converted to bile acids
B
HDL dapat
Which is true?
A.Men have higher HDL-C levels and lower total cholesterol and triglyceride levels than women
B.The difference in total cholesterol, however,
disappears after menopause as oestrogen decreases
C.Men and women both show a tendency toward increased total cholesterol, LDL-C, and triglyceride
concentrations with age.
D.The incidence of heart disease is strongly associated with serum cholesterol concentration, particularly LDL-C.
A
Baliktad.
False about arteriosclerosis
A.The relationship between heart disease and dyslipidemias stems from the deposition of lipids in artery walls.
B.Lipid deposits are frequently associated with increases serum concentrations of LDL-C or decreased HDL-C
C.For patients with established heart disease, aggressive treatment to reduce HDL-C levels below 100mg/L (2.6mmol/L) or even lower is effective in stabilization, and sometimes regression of plaques.
C
LDL DAPAT
false about FAMILIAL HYPERCHOLESTEROLEMIA (FH) A.Homozygotes for FH are common B.Heterozygotes for FH are rare C. BOTA D. NOTA
C
baliktad e :3
identify the FAMILIAL HYPERCHOLESTEROLEMIA (FH) symptoms
A.___ :cholesterol deposits under the skin
B. __ :cholesterol deposits in the cornea
tendinous/tuberous xanthomas
arcus
False about Lp(A) elevation
A. Higher Lp(a) levels have been observed in patients with CHD
B. Has a high degree of homology with plasminogen increasing plaque formation
C. Most LDL-lowering drugs have significant effect on Lp(a) concentration
C
insignificant dapat
identify type of cholesterol
reflects total cholesterol minus HDL-C and encompasses all cholesterol present in potentially atherogenic, apo B–containing lipoproteins [LDL, VLDL, IDL, and Lp(a)]
non-HDL Cholesterol
Which is false about non-HDL C?
A. Non–HDL-C is not reliable when measured in the non-fasting state
B. Studies have shown that elevated levels of non–HDL-C are associated with increased CVD risk even if the LDL- C levels are normal
C. Non–HDL-C has been found to be an independent predictor of CVD and for diabetes patients
A
reliable siya
T/F
hypobetalipoproteinemia is associated with isolated low levels of LDL-C
T
identify the disease
extreme hypoalphalipoproteinemia
HDL-C concentrations as low as 1 to 2 mg/dL (0.03 to
0.05 mmol/L) in homozygotes
total cholesterol concentrations of 50 to 80 mg/dL (1.3 to
2.1 mmol/L)
Tangier Disease
false about cholesterol measurement
A. At least 6hr fasting: preferred for total cholesterol testing, required for triglyceride testing
B. The lipoproteins, HDL and LDL are quantified based on their cholesterol content
A
12hr dapat
identify past method of cholesterol det
Hexane extraction after hydrolysis with alcoholic KOH Reaction with Liebermann- Burchard color reagent (sulfuric and acetic acids and acetic anhydride)
identify present method of cholesterol det
Gas chromatography–mass spectrometry (GC–MS):
Triglyceride value: used in the estimation of LDL-C by
what means of computation
Friedewald equation
Enum methods for sep & quanti of serum lipoproteins
- Ultracentrifugation
- Electrophoretic separations
- Chemical precipitation methods
- Immunochemical methods
- Chromatographic methods
identify the lipid measurement tool most common in clinical laboratories; designed for fully automated use with chemistry analyzers, using combinations of detergents and, antibodies to selectively assay cholesterol in lipoprotein classes
Direct homogeneous reagents -
Enum methods to measure HDL
Three-step method (reference method by CDC):
Direct precipitation method (simpler)
Identify HDL meas method
ultracentrifugation to remove VLDL
heparin manganese precipitation from the 1.006
g/mL infranate to remove LDL
analysis of supernatant cholesterol by the Abell-
Kendall assay
three step method
identify HDL meas method
direct dextran sulfate (50 kD) precipitation of serum
with Abell-Kendall cholesterol analysis
direct precipitation method
Point-of-care testing at the patient’s bedside, in the physician’s office, in wellness centers, and even in the
home
identify lipid meas tool
compact analyzer
Choline-containing phospholipids lecithin,
lysolecithin, and sphingomyelin are measured by an enzymatic reaction sequence using 3 enzymes. enum!
phospholipase D, choline oxidase, and horseradish peroxidase
fatty acid meas commonly analysed via ___
gas–liquid chromatography
