Lipoprotein Metabolism

Question 1

What is the only way to excrete cholesterol?

Answer 1

bile

Question 2

why are fats packaged into lipoprotien?

Answer 2

polar capsule allows them to move through water

Question 3

apolipoproteins

Answer 3

proteins attached to the outer shell of a lipoprotein

Question 4

what lipoproteins are high in triglycerides?

Answer 4

VLDL and chylomicron

Question 5

what lipoproteins are high in cholesterol esters?

Answer 5

LDL and HDL

Question 6

Apo A-1

Answer 6

associated with HDL

activates LCAT

Question 7

Apo B-48

Answer 7

associated with chylomicrons

Question 8

Mature chylomicrons

Answer 8

gain Apo C-11 and Apo E in addition to Apo B-48 which is present on all chylomicrons

Question 9

Apo B-100

Answer 9

associated with VLDL and LDL

C-terminal of B-100 binds to LDL receptor

Question 10

What apoproteins do nascent LDL have ?

Answer 10

B-100, C-11 and E

Question 11

What apoproteins do mature LDL have?

Answer 11

B-100

Question 12

What apoproteins do nascent VLDL have?

Answer 12

B-100

Question 13

What apoproteins do mature VLDL have?

Answer 13

B-100, C-II and E

Question 14

What apoproteins do mature HDL have?

Answer 14

A-1, C-11 and E

*nascent HDL only have A-1

Question 15

What is the source of C-11 and E for chylomicrons?

Answer 15

HDL

Question 16

What receptor do chylomicrons end up solely expressing?

Answer 16

they solely express E

Question 17

Apoprotein E and binding

Answer 17

able to bind the remnant receptors on liver

allows chlyomicron remnants to bind to liver

Question 18

LDL function

Answer 18

give cholesterol to peripheral tissues

Question 19

HDL function

Answer 19

retrieve excess cholesterol from tissues

Question 20

VLDL function

Answer 20

deliver triglycerides to tissues from liver

Question 21

chylomicron function

Answer 21

deliver triglyceride from intestine to liver

Question 22

What is the cofactor for LPL

Answer 22

C-11

Question 23

LPL function

Answer 23

break down triglycerides in VLDL and chylomicron to deliver FA to tissues

remaining glycerol returns to the liver

Question 24

Where is LPL located

Answer 24

in capillary beds

Question 25

What 3 enzymes are associated with reverse transport / HDL?

Answer 25

LCAT CETP SR-B1

Question 26

LCAT function

Answer 26

makes cholesterol ester so it can get into neutral core for transport by HDL cholesterol is now able to be transported back to the liver

Question 27

CETP function

Answer 27

move cholesterol ester from HDL to other lipoproteins

Question 28

how is cholesterol created from VLDL?

Answer 28

CETP moves cholesterol ester from HDL to LDL

Question 29

SR-B1 function

Answer 29

scavenger receptor directly transports cholesterol and ester to tissue or liver

Question 30

tissues that commonly require cholesterol express what receptor

Answer 30

SR-B1

Question 31

what tissues commonly require cholesterol?

Answer 31

adrenal cortex and sex organs need cholesterol to produce hormones

Question 32

What binds to the LDL receptor?

Answer 32

the C-terminal of Apo B-100

Question 33

How do chylomicrons bypass the liver?

Answer 33

move through the lymph first and then the blood

Question 34

bile acids

Answer 34

break down dietary fat and cholesterol to package into chylomicrons

Question 35

what is elevated in familial hypercholesterolemia?

Answer 35

LDL levels

Question 36

familial hypercholesterolemia genetic pattern

Answer 36

autosomal dominant / haploinsufficiency

Question 37

what form of familial hypercholesterolemia is most severe?

Answer 37

homozygous

Question 38

xanthuma

Answer 38

cutaneous deposit of cholesterol that can be seen in familial hypercholesterolemia

Question 39

statin MOA

Answer 39

block cholesterol production by blocking HMG CoA Reductase

Question 40

what causes familial hypercholesterolemia?

Answer 40

mutations in LDL receptor gene by mutating the LDLR, you are unable to uptake LDL which is a bad thing no uptake also indicates to liver artifically low LDL levels and liver will produce more cholesterol (even though levels in blood are high)

Question 41

PCSK-9 function

Answer 41

determines if LDL receptor will be degraded or re-expressed on the membrane PCSK-9 prefers degrading the receptor

Question 42

PCSK-9 inhibitor

Answer 42

by inhibiting PCSK-9, we recycle more LDL receptors which is good for lowering serum LDL

Question 43

Where does most serum cholesterol come from?

Answer 43

de novo synthesis in liver this is why statins work better than exercise in lowering cholesterol

Question 44

what are LDL and remanent receptors coated with?

Answer 44

clathrin