fatty acid delivery

Question 1

these are diet derived, packaged in the intestine to deliver lipids to various tissues. ApoB-48 is associated.

Answer 1

chylomicron

Question 2

________ activates lipoprotein lipase to release free fatty acids for fuel in adipose tissue, heart and skeletal muscle

Answer 2

apoC-II

Question 3

when fats are depleted, chylomicron remnants go to the liver for absorption via _______ mediated endocytosis

Answer 3

apoE

Question 4

these are packaged in the liver from diet derived and de-novo synthesized lipids. apoB-100 is associated

Answer 4

VLDL

Question 5

__________ take up free fatty acids, and convert them to TAGs for storage

Answer 5

adipocytes

Question 6

______ uses the TAG for energy

Answer 6

muscle

Question 7

these deliver cholesterol to various tissues. for example: muscle and adipose tissue have LDL-receptors and recognize apoB-100 on LDL

Answer 7

LDL

Question 8

these pick up cholesterol from extra-hepatic tissue and returns to liver (reverse cholesterol transport), where it can be metabolized

Answer 8

HDL

Question 9

is a sample of blood plasma that is chylomicron rich more cloudy or more clear?

Answer 9

cloudy

Question 10

________ is anchored to the cell surfaces of several tissues that are exposed to the circulation.

Answer 10

LPL - lipoprotein lipase

Question 11

what specific portion of the cell surface is LPL anchored to?

Answer 11

heparin sulfate proteioglycans

Question 12

what two tissues are the highest levels of expression of LDL found in

Answer 12

heart and adipose tissue

Question 13

does apoC-II activate or inhibit LPL

Answer 13

activates

Question 14

does apoC-III activate or inhibit LPL

Answer 14

inhibit

Question 15

____ hydrolyzes the triglycerides that are carried through the circulation by lipoproteins containing apoB-48 (chylomicrons) and apoB-100 (VLDL)

Answer 15

LPL

Question 16

the hydrolysis of triglycerides on VLDL by LPL leads to the formation of a ________ (smaller/larger) more dense lipoprotein within the circulation

Answer 16

smaller

Question 17

true/false: lipoprotein lipase deficiency is a genetic disorder; causes very low triglyceride levels in circulation and several health complications. fat intake has to be tresitrced to less than 20g/day

Answer 17

false - causes very high triglyceride levels

Question 18

who were the two scientists to discover the LDL receptor pathway?

Answer 18

Michael brown and Jospeh goldstein

Question 19

sit on the outer surface of many types of cells, where they pick up LDLs circulating in the bloodstream and transport them into the cell. Once inside the cell, the LDL is broken down to release cholesterol. The cholesterol is then used by the cell, stored, or removed from the body.

Answer 19

LDL receptor

Question 20

is the process ion removing non-hepatic (extra-hepatic) cholesterol for delivery to the liver, and ultimately for excretion from the body (e.g. cholesterol is used for bile acids/salts synthesis; bile is excreted)

Answer 20

reverse cholesterol transport (RCT)

Question 21

reverse cholesterol transport: RCT requires the transfer of cholesterol and phospholipids from cells to ___________ (almost exclusively proteins; very little lipid) in the circulation - a process called cholesterol efflux

Answer 21

nascent HDL

Question 22

reverse cholesterol transport: is the ability of HDL to scoop up cholesterol particles from plaques in the heart’s blood vessels and move those particles to the liver for disposal.

Answer 22

cholesterol efflux

Question 23

reverse cholesterol transport: nascent HDL is then converted to _______ in the circulation

Answer 23

mature HDL

Question 24

reverse cholesterol transport: mature HDL is then taken up by the _______ (only the lipids and not apoA-I)

Answer 24

liver

Question 25

true or false: only the lipid portion of HDL is taken up by the liver, not ApoA-I. therefore ApoA-I can be reused to form more HDL

Answer 25

true

Question 26

what enzyme is used to convert cholesteryl ester to cholesterol

Answer 26

cholesteryl ester hydrolase

Question 27

this transporter, also known as cholesterol efflux regulatory protein, efluxes lipids to lipid poor ApoA-I

Answer 27

ABCA1

Question 28

what does the conversion of nascent HDL to mature HDL require

Answer 28

enzyme and a transfer protein

Question 29

what enzyme is required for the conversion of nascent HDL to mature HDL

Answer 29

lecithin cholesterol acyl transferase (LCAT)

Question 30

what transfer protein is required for the conversion of nascent HDL to mature HDL

Answer 30

phospholipid transfer protein (PLTP)

Question 31

what enzyme is used to convert cholesterol to cholesteryl ester?

Answer 31

LCAT

Question 32

what is a cofactor for LCAT activity

Answer 32

ApoA-I

Question 33

this transfers excess phospholipids from apoB-100 containing lipoproteins (VLDL, LDL) to HDL.

Answer 33

phospholipid transfer protein

Question 34

what is the importance of phospholipid transfer protein (PLTP)?

Answer 34

- provides phospholipid to expand the HDL surface area - provides lecithin (or phosphatidylcholine) for LCAT activity - contributes to the metabolism of apoB-100 containing lipoproteins (VLDL) into LDL

Question 35

the major receptor responsible for selective uptake of HDL is _________

Answer 35

scavenger receptor class B type I (SR-BI)

Question 36

high dietary ______ increased cholesterol efflux in C57BL/6 mice

Answer 36

n-3 PUFA

Question 37

these act as amphipathic detergents that facilitate the enzymatic digestion and absorption of dietary fats in the intestine they are the principal route by which cholesterol is removed from the body (in the faces)

Answer 37

bile acids/salts

Question 38

where are bile acids/salts formed

Answer 38

liver

Question 39

where are bile acids/salts stored

Answer 39

gall bladder

Question 40

true/false: upon fat intake bile acids/salts are released into the intestine

Answer 40

true

Question 41

__________ is the rate limiting enzyme to convert cholesterol to bile acids

Answer 41

cholesterol 7-alpha hydroxyls (cyp7)

Question 42

what are some steroid hormones derived from cholesterol?

Answer 42

progesterone -> cortisol, corticosterone, testosterone corticosterone -> aldosterone testosterone -> estradiol

Question 43

is the main underlying cause of cardiovascular disease. it is a disease in which plaques build up in the walls of the arteries

Answer 43

atherosclerosis

Question 44

______ LDL cholesterol levels tend to correlate with atherosclerosis.

Answer 44

very high

Question 45

_____ LDL cholesterol levels are negatively associated with heart disease

Answer 45

low

Question 46

this pathogenic form of LDL is formed dye to excess hydrolysis of LDL triglycerides; this occurs when LDL levels are high. this cannot bind to the LDL receptor; it cannot be readily removed from the circulation, thus It is susceptible to chemical modifications (e.g. oxidation

Answer 46

small dense LDL (sd-LDL)

Question 47

this pathogenic form of LDL is the product of the oxidation of LDL protein and lipids.

Answer 47

oxidized LDL (oxLDL)

Question 48

what can prevent oxidation of LDL

Answer 48

dietary antioxidants (vitamin A,C,E)

Question 49

true/false: small density LDL particles are more atherogenic (can form plaques more easily)

Answer 49

true

Question 50

true/false: oxidized LDL is more atherogenic (can form plaques more easily)

Answer 50

true

Question 51

true/false: omega-3 fatty acids increase the amount of small density LDL particles

Answer 51

false! reduce the amount of sdLDL

Question 52

_____ LDL leads to excess lipid deposition and can promote atherosclerosis

Answer 52

high

Question 53

____ LDL reduces lipid deposition and can reduce the progression of atherosclerosis

Answer 53

low

Question 54

____ HDL leads to excess reverse cholesterol transport and can reduce the progression of atherosclerosis

Answer 54

high

Question 55

____ HDL results in less reverse cholesterol transport, thus excess deposited lipids from LDL are not removed

Answer 55

low

Question 56

these lower LDL by removing cholesterol from the liver in the form of bile acids/salts (to prevent the cholesterol from being packaged into VLDL) and by increasing the rate of reverse cholesterol transport e.g. cholestryamine and colestipol

Answer 56

bile acid sequestrants (bile acid/salt binding resins)

Question 57

this lowers LDL by reducing ,over triglyceride synthesis and increasing fat oxidation (reducing VLDL). e.g. fenofibrate, gemfibroizil

Answer 57

fibrates

Question 58

injectable treatment of antibodies that inhibit LDL receptor degradation (via PCSK9). e.g. evolocumab and alirocumab

Answer 58

LDL receptor degradation inhibitors (PCSK9 inhibitors)