Quiz 2: Lipids and Lipoproteins

Question 1

Which of the following are lipoproteins?

(a) Chylomicrons, VLDL, IDL, LDL, HDL
(b) Triglycerides
(c) Phospholipids
(d) Cholesterol

Answer 1

(a) Chylomicrons, VLDL, IDL, LDL, HDL

Question 2

Properties of lipids include:

(a) Insoluble in water
(b) Soluble in organic solvents such as alcohol
(c) Some lipids are a good source of energy, others for membranes, or a precursor for lipid hormones
(d) All of the above

Answer 2

(d) All of the above

Question 3

Which of the following are fatty acids?

(a) Arachidonic acid
(b) Linoleic acid
(c) Linolenic acid
(d) All of the above

Answer 3

(d) All of the above

Question 4

The difference between saturated, unsaturated, and polyunsaturated fatty acids are:

(a) Fatty acids have a single bond, no double bond
(b) Polyunsaturated fatty acids have multiple double bonds
(c) Unsaturated fatty acids have double bonds
(d) All of the above are true

Answer 4

(d) All of the above are true

Question 5

What phospholipids are used to asses fetal maturity?

(a) Phosphacidylethanolamine
(b) Phosphacidylglycerol
(c) Phosphacidylinositol
(d) Phosphacidylserine

Answer 5

(b) Phosphacidylglycerol

Question 6

What is the definition of a triglyceride?

(a) A diglyceride esterified with phosphoric acid and bound to a nitrogen containing base
(b) A lipid plus a protein
(c) A sterol compound found in most body tissue
(d) An ester formed from an alcohol glycerol and 3 fatty acids

Answer 6

(d) An ester formed from an alcohol glycerol and 3 fatty acids

Question 7

Several enzymatic triglyceride methods measure the production or consumption of:

(a) Diacetyl lutidine
(b) Fatty acids
(c) Glycerol
(d) NADH

Answer 7

(c) Glycerol

Question 8

The most likely cause for serum/plasma to appear milky is the presence of:

(a) Chylomicrons
(b) HDL
(c) LDL
(d) VLDL

Answer 8

(a) Chylomicrons

Question 9

Which lipoprotein is the major carrier of cholesterol to peripheral tissue?

(a) Chylomicrons
(b) HDL
(c) LDL
(d) VLDL

Answer 9

(c) LDL

Question 10

The physician requests an LDL cholesterol assay after receiving the following results on a 12 hour fasting lipemic sample. Total cholesterol = 220 mg/dL; triglycerides = 420 mg/dL; HDL-C= 40 mg/dL; how should the LDL cholesterol be determined?

(a) Dilute the specimen 1:10 and repeat all tests. Calculate LDL cholesterol using the Friedewald equation
(b) Perform a direct LDL assay
(c) Repeat the HDL cholesterol using a manganese-heparin precipitation method. Use the new result to calculate the LDL cholesterol
(d) Ultracentrifuge the sample and repeat the HDL cholesterol on the infranate. Use the new result to calculate the LDL cholesterol.

Answer 10

(b) Perform a direct LDL assay

Question 11

Exogenous triglycerides are transported into the plasma in which of the following forms:

(a) Cholesterol esters
(b) Chylomicrons
(c) LDL
(d) VLDL

Answer 11

(b) Chylomicrons

Question 12

A patient is admitted to the hospital with intense chest pains. The patient’s primary care physician requests the emergency department doctor to order several tests, including a lipid profile with cholesterol fractionation. Given the patient’s results provided below, what would be the LDL-C for this patient? Total cholesterol = 400 mg/dL; triglycerides = 300 mg/dL; HDL-C = 100 mg/dL; LP electrophoresis, pending.

(a) 160 mg/dL
(b) 200 mg/dL
(c) 240 mg/dL
(d) 300 mg/dL

Answer 12

(c) 240 mg/dL

Question 13

Which of the following would be most adversely affected by a nonfasting sample?

(a) Cholesterol
(b) HDL
(c) LDL
(d) Triglycerides

Answer 13

(c) LDL

Question 14

Select the order of mobility of lipoproteins electrophoresed on agarose at pH 8.6, versus ultracentrifugation which goes Chylomicrons, prebeta proteins, beta proteins, alpha proteins.

(a) Chylomicrons, pre-beta, beta, alpha
(b) Beta, pre-Beta, alpha, chylomicrons
(c) Chylomicrons, beta, pre-Beta, alpha
(d) Alpha, beta, pre-Beta, chylomicrons

Answer 14

(c) Chylomicrons, beta, pre-Beta, alpha

Question 15

Following ultracentrifugation of plasma, which fraction correlated with pre-β lipoprotein?

(a) VLDL
(b) LDL
(c) HDL
(d) Chylomicrons

Answer 15

(a) VLDL

Question 16

What is the most appropriate procedure when a fasting lipid study of triglyceride, total cholesterol, HDL cholesterol, and LDL cholesterol tests are ordered?

(a) 8 hours; nothing but water allowed
(b) 10 hours; water, smoking, coffee, tea (no sugar or cream) allowed
(c) 12 hours; nothing but water allowed
(d) 16 hours; water, smoking, coffee, tea (no sugar or cream) allowed

Answer 16

(c) 12 hours; nothing but water allowed

Question 17

Which of the following are true about apolipoproteins?

(a) Apoproteins include A,B,C,D,E
(b) Apoproteins are lipids that are part of the lipoprotein complex
(c) Apoproteins are water insoluble and are found inside the lipoprotein complex
(d) All of the above

Answer 17

(a) Apoproteins include A,B,C,D,E

Question 18

Which of the following enzymes is common to all enzymatic methods for triglyceride measurement?

(a) Glycerol kinase
(b) Glycerol phosphate dehydrogenase
(c) Glycerol phosphate oxidase
(d) Pyruvate kinase

Answer 18

(a) Glycerol kinase

Question 19

Which are the following values are out of reference intervals for adults?

(a) HDL 70 mg/dL
(b) LDL 90 mg/dL
(c) Total cholesterol 240 mg/dL
(d) Triglycerides 140 mg/dL

Answer 19

(c) Total cholesterol 240 mg/dL

Question 20

What are some methods that can be affected by lipemia if not corrected via analyzer or operator adjustments?

(a) Hemoglobin
(b) MCHC
(c) Spectophotometric methods
(d) All of the above

Answer 20

(d) All of the above