CLS Lipid Metabolism & Physiology 3

Question 1

Which dietary fatty acid class is most effective at raising LDL cholesterol levels?

Accepted Answer

Trans fatty acids

Answer

Trans fatty acids both raise LDL-C and lower HDL-C, making them uniquely atherogenic compared to saturated fats which raise both LDL and HDL.

Question 2

Lp(a) is formed when LDL binds covalently to which protein?

Accepted Answer

Apolipoprotein(a)

Answer

Lp(a) is formed by a disulfide bond between ApoB-100 on LDL and apolipoprotein(a), which structurally resembles plasminogen and may promote thrombosis and atherosclerosis.

Question 3

Which enzyme esterifies free cholesterol within HDL particles to form cholesteryl esters?

Accepted Answer

LCAT

Answer

Lecithin-cholesterol acyltransferase (LCAT) is activated by ApoA-I and esterifies free cholesterol in HDL, trapping it in the particle core and driving cholesterol efflux from tissues.

Question 4

A patient with type III hyperlipidemia (dysbetalipoproteinemia) has excess accumulation of which lipoprotein remnants?

Accepted Answer

VLDL remnants (IDL) and chylomicron remnants

Answer

Type III hyperlipidemia (familial dysbetalipoproteinemia) results from ApoE2 homozygosity, which impairs hepatic clearance of IDL and chylomicron remnants, causing equal elevations of cholesterol and triglycerides.

Question 5

In the exogenous lipid pathway, chylomicrons are assembled in which cells?

Accepted Answer

Intestinal enterocytes

Answer

Chylomicrons are synthesized in intestinal enterocytes from dietary lipids and secreted into lymphatic lacteals before entering the circulation via the thoracic duct.

(CLS) Clinical Lipid Specialist Certification Practice Test

(CLS) Clinical Lipid Specialist Certification Practice Test

CLS Lipid Metabolism & Physiology 3