Lipids and Lipoproteins

Question 1

Fatty acids

Answer 1

Chains of molecules, major constituents of triglycerides and phospholipids

Question 2

Triglyceride

Answer 2

One glycerol, 3 fatty acids

95% of all fats in adipose tissue, transported by chylomicrons and VLDL

Question 3

Cholesterol

Answer 3

Unsaturated steroid alcohol, esterified and unesterified form
Precursor of synthesis of bile acids, steroid hormones, and vitamin D
Carried by LDL

Question 4

Phospholipid

Answer 4

One glycerol, two fatty acids

On surface of lipid layers, constituents of cell membranes and outer shells of lipoprotein molecules

Question 5

Lipoproteins

Answer 5

Combine water-insoluble dietary lipids and water-soluble proteins so they can be transported

Question 6

Chylomicrons

Answer 6

Largest lipoproteins and lowest density, formed in intestines and transport triglycerides, 86% triglyceride
Give plasma turbid appearance, float to top and form creamy layer

Question 7

VLDL

Answer 7

Synthesized in liver, 55% triglycerides, secreted into blood by liver for metabolism in peripheral tissues

Question 8

Intermediate density lipoprotein (IDL)

Answer 8

Cary endogenous triglycerides and cholesterol, 23% triglycerides, 38% cholesterol

Question 9

LDL

Answer 9

Major cholesterol carrier, “bad cholesterol”, 50% cholesterol

Question 10

HDL

Answer 10

Synthesized in intestine and liver cells, “good cholesterol”, 50% protein
Removes excess cholesterol from peripheral tissues and transports it to catabolic sites, antiatherogenic effect

Question 11

Lp(a)

Answer 11

Made of cholesterol, phospholipids, and apolipoprotein (a)

Increased: risk of coronary heart disease, MI, and cerebrovascular disease

Question 12

Type I hyperlipoproteinemia

Answer 12

Elevated chylomicrons, creamy layer over clear serum
Normal to elevated cholesterol
Elevated triglycerides, Apo B-48, and Apo A-IV

Question 13

Type IIa hyperlipoproteinemia

Answer 13

Increased LDL, clear serum
Elevated cholesterol and Apo-B 100
Normal triglycerides

Question 14

Type IIb hyperlipoproteinemia

Answer 14

Increased LDL and VLDL, clear/turbid appearance

Elevated cholesterol, triglycerides, and Apo B-100

Question 15

Type III hyperlipoproteinemia

Answer 15

Increased IDL, creamy layer over turbid serum
Elevated cholesterol, triglycerides, and Apo E-II
Decreased Apo E-III and Apo E-IV

Question 16

Type IV hyperlipoproteinemia

Answer 16

Increased VLDL, turbid serum
Normal to elevated cholesterol
Elevated triglycerides and Apo B-100
Increased or decreased Apo C-II

Question 17

Type V hyperlipoproteinemia

Answer 17

Increased VLDL and chylomicrons, turbid with creamy layer
Elevated cholesterol, triglycerides, Apo B-48, and Apo B-100
Increased or decreased Apo C-II

Question 18

Abetalipoproteinemia

Answer 18

Very low cholesterol, triglycerides, LDL, and Apo B-100

Question 19

Hypobetalipoproteinemia

Answer 19

Can’t synthesize Apo B-100 and Apo B-48

Low cholesterol and triglycerides

Question 20

Hypoalphalipoproteinemia

Answer 20

Elevated triglycerides and low HDL

Question 21

Tangier disease

Answer 21

HDL absent, Apo A-I and Apo A-II very low
Low LDL and total cholesterol
Normal to increased triglycerides

Question 22

HDL rest methodology

Answer 22

Precipitate LDL and VLDL then assay supernatant

Question 23

LDL test methodology

Answer 23

Friedewald Calculation:
LDL = total cholesterol - (HDL + TG/5)

Homogenous: detergents block HDL and VLDL, LDL forms colored product

Question 24

Apo A-1

Answer 24

Major protein in HDL

Question 25

Apo B-100

Answer 25

Major protein in LDL

Question 26

Lp(a)

Answer 26

Independent risk factor for decreased fibrinolysis which can cause coronary heart disease and stroke