Lipid Transport

Question 1

lipids are transported in ____ as ____

Answer 1

plasma; lipoproteins

Question 2

name the apoproteins

Answer 2

A
C
E
B48
B100

Question 3

location of apoprotein A

Answer 3

HDL

Question 4

location of apoprotein C

Answer 4

HDL

Question 5

location of apoprotein E

Answer 5

HDL

Question 6

location of apoprotein B48

Answer 6

chylomicron

Question 7

location of apoprotein B100

Answer 7

VLDL/LDL

Question 8

function of apoprotein A

Answer 8

activator for enzyme: LCAT (lecithin cholesterol acyl transferase)

Question 9

function of apoprotein B48

Answer 9

ligand

Question 10

function of apoprotein B100

Answer 10

ligand

Question 11

function of apoprotein C

Answer 11

structural

Question 12

function of apoprotein E

Answer 12

ligand

Question 13

name the classes of lipoproteins from largest to smallest

Answer 13

Chylomicron
VLDL
LDL
HDL

Question 14

chylomicron density

Answer 14

least dense

Question 15

VLDL density

Answer 15

very low density

Question 16

LDL density

Answer 16

low density

Question 17

HDL density

Answer 17

high density

Question 18

chylomicron transport

Answer 18

dietary fats (exogenous lipids)

Question 19

VLDL transport

Answer 19

endogenous lipids made in liver
mainly TAG and some cholesterol esters

Question 20

LDL transport

Answer 20

mainly cholesterol esters

Question 21

LDL formation

Answer 21

after action of lipoprotein lipase on VLDL, and LDL is formed

Question 22

HDL transport

Answer 22

mainly protein
carries cholesterol back to liver

Question 23

____ move into tissue when LDL binds to ____ receptor in arterial smooth muscle cells, fibroblasts, macrophages

Answer 23

cholesterol esters; B100

Question 24

reverse cholesterol transport

Answer 24

1. liver synthesizes nascent HDL (discoidal)
2. discoidal HDL uptakes & esterifies cholesterol from tissue & becomes HDL3
3. HDL3 becomes bigger & less dense –> HDL2
4. hepatic lipase allows cholesterol & cholesterol esters to be unloaded into liver –> forms HDL3
5. HDL3 re-enters circulation

Question 25

LCAT (lecithin-cholesterol acyltransferase)

Answer 25

• converts free cholesterol into cholesterol esters and lysolecithin
• cholesterol esters move into HDL core
• lysolecithin is transferred to albumin

Question 26

impact of sex hormones on hepatic lipase

Answer 26

• increased by androgens (testosterone; lowers HDL in men)
• decreased by estrogens (raises HDL in menstruating women)

Question 27

higher levels of HDL reduce the risk of ____

Answer 27

atherosclerosis

Question 28

factors that increase HDL

Answer 28

1. reduced refine carbohydrate diets
2. increase action of lipoprotein lipase (due to exercise)
3. estrogen (pre-menopausal women)