Lipids, Lipoproteins, Apolipoproteins and other cardiac risk factors

Question 1

1. Which of the following formulas shows the correct calculation for indirectly measuring LDL-C (Friedewald
   formula)?

a. LDL-C = HDL-C + (Triglyceride/5)
b. LDL-C = Total cholesterol − (HDL-C) − (Triglyceride/5)
c. LDL-C = Total cholesterol + HDL-C + (Triglyceride/5)
d. LDL-C = HDL-C − (Triglyceride/5)

Answer 1

b. LDL-C = Total cholesterol − (HDL-C) − (Triglyceride/5)

Question 2

2. The protein component of a lipoprotein is referred to as:
   a. terpene.
   b. apolipoprotein.
   c. prostaglandin.
   d. phospholipid.

Answer 2

b. apolipoprotein.

Question 3

3. The lipoprotein that contains a carbohydrate-rich protein covalently bound to apo B-100 and a special protein
   motif called the “kringle” domain is:
   a. LDL.
   b. HDL.
   c. chylomicron.
   d. lipoprotein(a).

Answer 3

d. lipoprotein(a).

Question 4

4. What lipoprotein transports mostly cholesteryl esters
   through the blood?
   a. LDL
   b. VLDL
   c. Chylomicrons
   d. Lipoprotein(a)

Answer 4

a. LDL

Question 5

5. The enzyme that is critical for hydrolysis of triglycerides
   on chylomicrons for their conversion to chylomicron
   remnants is:
   a. cholesterol oxidase.
   b. glycerol kinase
   c. lipoprotein lipase.
   d. HMG-CoA reductase

Answer 5

c. lipoprotein lipase.

Question 6

6. The rate-limiting enzyme in cholesterol biosynthesis that
   is inhibited by statin drugs is:
   a. cholesterol oxidase.
   b. glycerol kinase
   c. lipoprotein lipase.
   d. HMG-CoA reductase

Answer 6

d. HMG-CoA reductase

Question 7

7. Which of the following lipid metabolic pathways has a
   role in transferring hepatically derived lipids, particularly triglyceride, to peripheral cells for energy metabolism?

a. Exogenous pathway
b. Endogenous pathway
c. Intracellular cholesterol transport pathway
d. Reverse cholesterol transport pathway

Answer 7

d. Reverse cholesterol transport pathway

Question 8

8. The formation of mixed micelles containing unesterified
   cholesterol, fatty acids, monoglycerides, phospholipids,
   and bile acids is referred to as:
   a. emulsification.
   b. denaturation.
   c. esterification.
   d. saturation.

Answer 8

a. emulsification.

Question 9

9. With regard to lipids, a carboxyl (−COOH) with a long
   side chain (R) containing an even number of carbon
   atoms that is important in human nutrition and metabolism is a type of lipid referred to as a(n):
   a. acylglycerol.
   b. ester.
   c. fatty acid.
   d. terpene

Answer 9

c. fatty acid.

Question 10

10. In the laboratory analysis of triglycerides, the initial step
    in all methods is:

a. phosphorylation of glycerol catalyzed by glycerokinase.
b. oxidation of cholesterol by cholesterol oxidase.
c. hydrolysis of triglyceride by lipase.
d. reduction of phenol and H2O2 by peroxidase.

Answer 10

c. hydrolysis of triglyceride by lipase.