Lipids and Lipoprotein

Question 1

Protein molecules in lipoprotein metabolism, structural proteins, and ligands for cell receptors.

Answer 1

Apolipoproteins

Question 2

Amphipathic lipids

Answer 2

Phospholipids and non-esterified cholesterol.

Question 3

Core components of lipoproteins

Answer 3

Neutral lipids: Triglycerides (TAG), cholesterol esters, free fatty acids (NEFA).

Question 4

HDL surrogate markers

Answer 4

Apolipoproteins A-I

Question 5

Apolipoprotein A-I function

Answer 5

HDL structural protein, LCAT activator.

Question 6

Plasma concentration of A-I

Answer 6

100-200 mg/dL.

Question 7

Apolipoprotein A-II function

Answer 7

HDL structural protein.

Question 8

Plasma concentration of A-II

Answer 8

20-50 mg/dL.

Question 9

Apolipoprotein A-IV function structural protein for

Answer 9

CM, VLDL, HDL.

Question 10

Plasma concentration of A-IV

Answer 10

10-20 mg/dL.

Question 11

Apolipoprotein B-100 function

Answer 11

Structural protein for VLDL, IDL, LDL; LDL receptor ligand.

Question 12

Plasma concentration of B-100

Answer 12

70-125 mg/dL.

Question 13

Apolipoprotein B-48 function

Answer 13

Structural protein for CM; remnant receptor ligand.

Question 14

Plasma concentration of B-48

Answer 14

<5 mg/dL.

Question 15

Apolipoprotein C-I function

Answer 15

Structural protein for CM, VLDL, HDL.

Question 16

Plasma concentration of C-I

Answer 16

5-8 mg/dL.

Question 17

Apolipoprotein C-II function

Answer 17

Structural protein; LPL cofactor.

Question 18

Plasma concentration of C-II

Answer 18

3-7 mg/dL.

Question 19

Apolipoprotein C-III function

Answer 19

Structural protein; LPL inhibitor.

Question 20

Plasma concentration of C-III

Answer 20

10-12 mg/dL.

Question 21

Apolipoprotein E function

Answer 21

Recognition factor for targeting CM and VLDL remnants to hepatic receptor.

Question 22

Plasma concentration of E

Answer 22

3-15 mg/dL.

Question 23

Catalyzes the esterification of cholesterol

Answer 23

Lecithin cholesterol acyltransferase (LCAT)

Question 24

Mediates endocytosis of lipoproteins, especially LDL

Answer 24

LDL Receptor (LDL-R)

Question 25

Catalyzes hydrolysis of TG in lipoproteins, releasing free fatty acids and glycerol

Answer 25

Lipoprotein lipase (LPL)

Question 26

Chylomicron Density

Answer 26

<0.93

Question 27

VLDL Density

Answer 27

0.93 - 1.006

Question 28

LDL Density

Answer 28

1.019 - 1.063

Question 29

HDL Density

Answer 29

1.063 - 1.21

Question 30

Electrophoretic Mobility of apolipoproteins from origin to anode

Answer 30

Chylomicron, B-LDL, IDL, Pre-B (VLDL), A (HDL)

Question 31

Ultracentrifuge Density (Top to Bottom)

Answer 31

Chylomicron, VLDL, IDL, LDL, HDL

Question 32

Chylomicron Major Component

Answer 32

Triglyceride (Exogenous), Apolipoproteins B48, C, E

Question 33

VLDL Major Component

Answer 33

Triglyceride (Endogenous), Apolipoproteins B100, C, E

Question 34

LDL Major Component

Answer 34

Cholesterol (>50%), Apolipoprotein B100

Question 35

HDL Major Component

Answer 35

Protein 50% and Phospholipids, Apolipoproteins A-I, A-II, C, E

Question 36

Chylomicron transportation

Answer 36

Transports Exogenous Lipids

Question 37

VLDL transportation

Answer 37

Transports Endogenous Lipids

Question 38

LDL transportation

Answer 38

Transports Cholesterol to Peripheral Tissues (Atherogenic)

Question 39

HDL

Answer 39

Reverse Cholesterol Transport (Tissues to Liver)

Question 40

Involves lipid absorption, exogenous, endogenous, and reverse cholesterol transport pathways

Answer 40

Lipoprotein Metabolism

Question 41

Lipid Absorption

Answer 41

Conversion of dietary lipids into more polar compounds by Pancreatic Lipase facilitated by bile

Question 42

Steatorrhea

Answer 42

Excess fat in feces, may indicate infection or lipid absorption issue

Question 43

Triglyceride Conversion (Lipid Absorption)

Answer 43

Triglyceride → Monoglycerides for better absorption

Question 44

Cholesterol Ester Conversion

Answer 44

Cholesterol esters → Free cholesterol for absorption

Question 45

Phospholipid Conversion for absorption

Answer 45

Phospholipids → Lysophospholipids

Question 46

Exogenous Pathway

Answer 46

Chylomicrons carry dietary lipids from the intestine to circulation

Question 47

Lipoprotein Lipase (LPL) Action

Answer 47

Hydrolyzes triglycerides in chylomicrons into fatty acids and glycerol

Question 48

Lipolytic product of VLDL catabolism, intermediate between VLDL and LDL in density, protein, and lipid content

Answer 48

IDL (Minor Lipoprotein)

Question 49

Floating B-lipoprotein with high cholesterol content, seen in type 3 hyperlipoproteinemia or dysbetalipoproteinemia

Answer 49

B-VLDL

Question 50

Prothrombotic lipoprotein with Apo(a) homologous to plasminogen, associated with stroke, MI, and CHD

Answer 50

Lp(a)

Question 51

Abnormal lipoprotein associated with obstructive biliary disease and LCAT deficiency, composed of phospholipids and non-esterified cholesterol

Answer 51

LpX

Question 52

Minor lipoprotein found with Albumin, involved in lipid transport

Answer 52

Apo C w/ Albumin

Question 53

LDL Density & Mobility

Answer 53

LDL density and mobility are similar to VLDL, with a role in cholesterol transport to peripheral tissues