FINALS - LIPIDS AND LIPOPROTEIN Flashcards
What is the main function of chylomicrons?
Transport dietary triglycerides to peripheral tissues
Which lipoprotein is responsible for redistributing dietary and hepatic-synthesized triglycerides during fasting?
VLDL
Which lipoprotein gathers up excess cholesterol for transport back to the liver?
LDL
What disease is associated with abnormal serum lipids (dyslipidemia)?
Coronary Heart Disease (CHD)
What is the consequence of having elevated levels of Intermediate-Density Lipoproteins (IDLs)?
Higher risk of peripheral vascular disease (PVD) and coronary artery disease (CAD)
Which type of fatty acids do most triglycerides from plant sources contain?
Polyunsaturated fatty acids
What type of fatty acid configuration typically forms oils at room temperature?
Cis unsaturated fatty acids
In what form do fatty acids mostly exist in plasma?
Constituent of triglycerides or phospholipids
Which type of lipoprotein is rich in triglycerides and is the major carrier of endogenous triglycerides?
VLDL
What is a characteristic feature of LDL particles?
Contain Apo B100 and are cholesterol-rich
Which lipoprotein particles are described as being very hydrophobic and virtually water insoluble?
Triglycerides
What type of bond links Apo(a) to Apo B100 in Lp(a) particles?
Disulfide bond
What type of bond attaches fatty acids to the glycerol backbone in triglycerides?
Ester bond
Which lipoprotein is associated with an increased CHD risk when its particles are small and dense?
LDL
What is the role of cholesterol in the body?
Facilitate triglyceride transport by lipoproteins
Maintain normal structure and integrity of cell
membranes
Act as a precursor for steroid hormone synthesis
What determines the size and density heterogeneity of Lp(a) particles?
The number of repeating peptide sequences called kringles
What condition is associated with elevated levels of Lp(a) (>30 mg/dL)?
Premature CHD and stroke
What primarily affects the plasma levels of Lp(a) within an individual?
Isoform size
What is the primary mechanism proposed to explain the antiatherogenic property of HDL?
Reverse cholesterol transport
Which organ is postulated to be responsible for the removal of Lp(a)?
Kidney
Which type of HDL is larger and less dense?
HDL2
What percentage of dietary triglycerides are typically absorbed by the intestine?
Greater than 90%
Which pathway involves the transport of fatty acids generated during lipolysis to peripheral cells?
Exogenous pathway
What forms large aggregates with bile acids during lipid absorption?
Micelles
Where are newly synthesized chylomicrons initially secreted?
Into the lacteals
Dyslipidemia as a risk factor for CVD is well-documented to begin in which age group?
Childhood
What happens to VLDL particles after lipolysis in the endogenous pathway?
They become IDLs or VLDL remnants
What is the primary underlying cause of arteriosclerosis?
Buildup of cholesterol plaques
Which type of arteriosclerosis involves the hardening and narrowing of large arteries?
Atherosclerosis
What can fatty streaks develop into over time?
Plaques
What is the term for cholesterol deposits in the skin that form nodules?
Xanthomas
Which condition is associated with cholesterol deposits in tendons?
Familial hypercholesterolemia
Hypertriglyceridemia with a triglyceride level greater than 500 mg/dL is considered:
Very high
Which hormone is known to influence serum triglyceride levels by triggering hormone-sensitive lipase?
Epinephrine
Combined hyperlipidemia involves the elevation of which serum levels?
Both cholesterol and triglycerides
Elevations in Lp(a) levels in conjunction with LDL are associated with increased risk for which conditions?
CHD and CVD
Hypobetalipoproteinemia is characterized by low levels of which lipoprotein?
LDL
What characterizes hypoalphalipoproteinemia?
Isolated decrease in HDL
Which of the following conditions is associated with fatty acid synthesis due to increased shunting of glucose into the pentose pathway?
Diabetes mellitus
Why are lipids and lipoproteins measured in clinical practice?
To estimate the risk of coronary heart disease (CHD)
Which type of sample is typically preferred for total cholesterol testing?
Serum or plasma specimens from fasting patients
What can be done to a serum/plasma specimen to preserve it if analysis is delayed?
Refrigerate at 4°C
Why are triglyceride measurements usually done on a fasting sample?
Because triglycerides can significantly increase after a meal
What physical properties are used in the separation and quantitation of serum lipoproteins?
Density, size, charge, and apolipoprotein content
Which method combines ultracentrifugation and chemical precipitation for LDL-C quantitation?
β-quantification
What is Apo A1 commonly used to measure in clinical diagnostics?
HDL levels as cholesterol content
Which apolipoprotein is considered a better indicator of atherogenic particles than LDL-C?
Apo B
Which choline-containing phospholipids account for at least 95% of total phospholipids in serum?
Lecithin, lysolecithin, and sphingomyelin
Which variant of LDL has been shown as an independent indicator of CHD risk?
Lp(a)
Why is ultracentrifugation preferred for VLDL separation in LDL-C quantitation?
Other methods may have interference from chylomicrons
