Lipoproteins and Apolipoproteins (TOPIC 1)

Question 1

are spherical shape which transports lipids such as cholesterol and triglycerides.

Answer 1

Lipoproteins

Question 2

Composed of lipids and protein (apolipoproteins).

Answer 2

Lipoproteins

Question 3

are found on the surface of the lipoproteins.

Answer 3

Apolipoproteins

Question 4

Functions are maintenance of structural integrity, binds to cell receptor and activators or inhibitors of enzymes.

Answer 4

Apolipoproteins

Question 5

Types of lipoproteins

Answer 5

ULDL- Chylomicrons
VLDL
IDL
LDL
HDL

Question 6

Largest lipoprotein, produced in the intestinal mucosal cells.

Answer 6

CHYLOMICRONS

Question 7

Composition: 80-90 % triglycerides (majority)

Answer 7

CHYLOMICRONS

Question 8

Transports exogenous (dietary lipids) to liver and peripheral cells such as adipose tissue.

Answer 8

CHYLOMICRONS

Question 8

Forms a milky or creamy layer at the top of the plasma. (lipemic).

Answer 8

CHYLOMICRONS

Question 9

Contain lipase which hydrolysed cholesterol and triglycerides resulting to formation of chylomicron remnants which uptake by the liver.

Answer 9

CHYLOMICRONS

Question 10

Lowest density and no electrophoretic mobility.

Answer 10

CHYLOMICRONS

Question 11

Lipemic sample means high amount of chylomicrons and triglycerides.

Answer 11

CHYLOMICRONS

Question 12

Pre beta lipoprotein.

Answer 12

VLDL(Very low density lipoprotein)

Question 13

Composition: 45-65 % triglycerides.

Answer 13

VLDL(Very low density lipoprotein)

Question 14

Triglyceride composition of Chylomicrons

Answer 14

Composition: 80-90 % triglycerides (majority)

Question 15

Triglyceride composition of VLDL(Very low density lipoprotein)

Answer 15

Composition: 45-65 % triglycerides.

Question 16

Apolipoproteins of VLDL

Answer 16

apo B-100, C-I, C-II, C-III and E.

Question 16

Synthesized from chylomicron remnant

Answer 16

VLDL(Very low density lipoprotein)

Question 17

Apolipoprotein of chylomicrons

Answer 17

apo B-48

Question 18

Transports endogenous triglycerides from hepatic to peripheral tissues.

Answer 18

VLDL(Very low density lipoprotein)

Question 19

deposits fats to the adipose tissue eventually degraded by lipoprotein lipase resulting decrease in size.

Answer 19

VLDL(Very low density lipoprotein)

Question 20

Intermediate between VLDL and LDL.

Answer 20

IDL(intermediate density lipoprotein)

Question 21

Partly depleted triglyceride.

Answer 21

IDL(intermediate density lipoprotein)

Question 22

interacts with HDL giving off most of its TAG content in exchange of cholesterol resulting to formation of LDL.

Answer 22

IDL(intermediate density lipoprotein)

Question 23

Composition: 45-50 % cholesterol.

Answer 23

LDL(low density lipoprotein)

Question 24

LDL(low density lipoprotein) cholesterol composition

Answer 24

Composition: 45-50 % cholesterol.

Question 25

apolipoprotein of LDL

Answer 25

B-100

Question 26

“Bad cholesterol” by transporting cholesterol from liver to tissues. Used as a marker for coronary artery disease.

Answer 26

LDL(low density lipoprotein)

Question 27

Beta lipoprotein, follow the mobility of

Answer 27

beta globulin.

Question 28

Composition: 15-20 % cholesterol and 45-55 % proteins.

Answer 28

HDL(high density lipoprotein)

Question 29

HDL cholesterol and protein composition

Answer 29

15-20% cholesterol 45-55% proteins

Question 29

Produce by liver and intestines.

Answer 29

HDL(high density lipoprotein)

Question 29

“Good cholesterol” because it acts as “scavenger of lipids”,

Answer 29

HDL(high density lipoprotein)

Question 29

Apolipoprotein of HDL

Answer 29

apo A-I apo A-II apoC

Question 30

transport cholesterol from tissues to liver for catabolism to form bile acids. (reverse cholesterol transport).

Answer 30

HDL(high density lipoprotein)

Question 30

Alpha lipoprotein, follow mobility of

Answer 30

alpha globulin

Question 31

Fastest migrating lipoprotein.

Answer 31

Alpha lipoprotein

Question 31

transporting cholesterol from liver to peripheral tissues such as adrenal gland, gonads, and blood vessels.

Answer 31

LDL

Question 32

transport cholesterol from peripheral tissues to liver for recycling

Answer 32

HDL

Question 33

Also known as the “sinking beta lipoprotein”.

Answer 33

Abnormal lipoprotein

Question 34

Same with LDL except in density and mobility.

Answer 34

Abnormal lipoprotein

Question 35

Associated with increase risk of coronary artery disease and cerebrovascular disease.

Answer 35

Abnormal lipoprotein

Question 35

Apolipoprotein of Abnormal Lipoprotein

Answer 35

apo (a) bound to apo B-100 by disulfide bonds

Question 36

Floating beta lipoprotein.

Answer 36

Beta VLDL

Question 37

Contains higher cholesterol than triglycerides. Found in VLDL density range, electropheritically found in LDL.

Answer 37

Beta VLDL

Question 37

Seen in type III hyperlipoproteinemia.

Answer 37

Beta VLDL

Question 37

Homologous with plasminogen which interfere with clot lysis.

Answer 37

Abnormal lipoprotein

Question 38

Composed mainly by unesterified cholesterol and phospholipids.

Answer 38

LpX

Question 38

Migrates towards the cathode in electrophoresis.

Answer 38

LpX

Question 39

Found in patient obstructive biliary disease.

Answer 39

LpX

Question 40

Separation of lipoproteins

Answer 40

Ultracentrifugation Electrophoresis

Question 41

Separation is based on net charges.

Answer 41

Serum Electrophoresis

Question 42

Lipoproteins are run in gel , electric current in apply to facilitate migration along the surface of gel. Stain is applied to visualize the band formation.

Answer 42

Serum Electrophoresis

Question 43

Stain/dye for Serum Electrophoresis

Answer 43

Fat Red 7B, Sudan Black B, Oil Red O

Question 44

Lipoprotein migration pattern in Electropheresis HDL VLDL LDL Chylomicrons

Answer 44

Alpha region Pre-beta region Beta region Does not migrate

Question 45

Other techniques of Separation of plasma proteins

Answer 45

Chromatographic technique Standing plasma test/plasma appearance test- Immunochemical methods-

Question 46

use of antibody to specific apolipoproteins.

Answer 46

Immunochemical methods-

Question 47

stand EDTA blood for 10-18 hours in dark refrigerator

Answer 47

Standing plasma test/plasma appearance test-

Question 48

found on the surface of the lipoproteins.

Answer 48

Apolipoproteins

Question 49

Functions structural integrity binds to cell receptor activators or inhibitors of lipoprotein associated enzymes.

Answer 49

Apolipoproteins

Question 50

catalyses the transfer of excess cellular cholesterol from peripheral tissues to the liver to be catabolized to bile this process is known as Reverse cholesterol transport (RCT).

Answer 50

Lecithin cholesterol acyl transferase (LCAT)-

Question 51

catalyses the metabolism of serum triglycerides by hydrolysis in chylomicrons and VLDL into FFA and glycerol for energy production or storage.

Answer 51

Lipoprotein lipase (LPL)-

Question 52

Types of Apolipoprotein A (major protein of HDL)

Answer 52

A1 – activates LCAT(Lecithin-cholesterol acyl transferase) A2 – inhibits L-CAT

Question 53

Types of Lipoprotein Little A Antigen

Answer 53

occurs in variant forms of LDL known as “sinking pre-beta lipoprotein”

Question 53

Types of Apolipoprotein E found in chylomicrons, VLDL, HDL and LDL

Answer 53

Increase the hepatic uptake of lipoproteins due to LDL receptor. Involves in the metabolism of chylomicron remnant and VLDL E2 – associated with dysbetalipoproteinemia (ApoE2/E2 homozygosity genotype) E4- associated with Alzheimer’s disease

Question 53

Types of Apolipoprotein C (mostly found in chylomicrons, VLDL and HDL)

Answer 53

C1 – activates L-CAT C2 – LPL (lipoprotein lipase enzyme) activators, inhibits binding of VLDL and chylomicron to hepatic receptor C3 – inhibits LPL (lipoprotein lipase)

Question 54

Types of Apolipoprotein B (major content of VLDL and chylomicrons)

Answer 54

B100 – found in VLDL, synthesized in the liver. B48 – found in chylomicrons and in patient with defects in chylomicron clearance. Synthesized in the intestine (enterocytes).