Lipids & Lipoproteins

Question 1

they are a rich source of energy and an efficient way for

the body to store excess calories.

Answer 1

Lipids

Question 2

also precursors for the steroid

hormones, prostaglandins, leukotrienes, and lipoxins.

Answer 2

Lipids

Question 3

found as a constituent of triglycerides or

phospholipids

Answer 3

Fatty acids

Question 4

No double bonds

Answer 4

saturated

Question 5

One double bond

Answer 5

monounsaturated

Question 6

two or more double bonds

Answer 6

polyunsaturated

Question 7

The major dietary trans fatty acid is _______, an 18-

carbon fatty acid with one double bond.

Answer 7

elaidic acid

Question 8

essential fatty acids.

Answer 8

linoleic and

linolenic acids

Question 9

omega-3, omega-6, and

omega-9 families,

Answer 9

polyunsaturated fatty acids

Question 10

are precursors for the synthesis of eicosanoids that include prostaglandins,
thromboxanes, prostacyclins, and leukotrienes.

Answer 10

polyunsaturated fatty acids

Question 11

contain three fatty acid
molecules attached to one molecule of glycerol by ester bonds in one of three
stereochemically distinct bonding positions

Answer 11

triglycerides

Question 12

Because it is uncharged, triglyceride

is classified as a _____ lipid.

Answer 12

neutral

Question 13

has a choline head group and is the most common phospholipid found on
lipoproteins and in cell membranes.

Answer 13

Phosphatidylcholine (often referred as lecithin)

Question 14

the most abundant phospholipids in the body.

Answer 14

phosphatidylcholine and

phosphatidylethanolamine

Question 15

unsaturated steroid alcohol containing four rings (A, B, C, and
D), and it has a single C–H side chain tail similar to a fatty acid in its physical
properties

Answer 15

Cholesterol

Question 16

classified as a neutral lipid and are not found on the
surface of lipid layers but instead are located in the center of intracellular lipid
droplets or in the hydrophobic core of lipoproteins, along with triglycerides.

Answer 16

cholesteryl ester

Question 17

Cholesterol is almost exclusively synthesized by animals, but plants do
contain other sterols (called ______)

Answer 17

phytosterols

Question 18

Bile acids that promote fat absorption

in the intestine by acting as detergents.

Answer 18

cholic acid and chenodeoxycholic acid,

Question 19

TRUE/FALSE: The size

of the lipoprotein particle correlates with its core neutral lipid content.

Answer 19

TRUE

Question 20

Apolipoproteins contain
a structural motif called an _________, which accounts for the
ability of these proteins to bind to lipids.

Answer 20

amphipathic alpha helix

Question 21

They are the major carriers of endogenous (hepatic-derived)
triglycerides and transfer triglycerides from the liver to peripheral tissue mostly
during the fasting state for energy utilization and storage.

Answer 21

Very-Low-Density Lipoproteins

Question 22

the delivery of dietary lipids to hepatic and

peripheral cells.

Answer 22

Chylomicrons

Question 23

referred to as VLDL remnants,

normally only exist transiently during the conversion of VLDL to LDL.

Answer 23

Intermediate-Density Lipoproteins

Question 24

Macrophages that take
up too much lipid become filled with intracellular lipid drops and turn into _______, which is the predominant cell type of fatty streaks, an early precursor of
atherosclerotic plaques.

Answer 24

foam

cells

Question 25

They form as a consequence of the | lipolysis of VLDL.

Answer 25

Low-Density Lipoproteins

Question 26

are LDL-like particles that contain one molecule of apo (a) linked to apo B-100 by a single disulfide bond.

Answer 26

Lp(a)

Question 27

TRUE/FALSE: Elevated levels of Lp(a) (>30 mg/dL) are now known to increase the risk of premature CHD and stroke.

Answer 27

TRUE

Question 28

Lp(a) particles are heterogeneous in both size and density, as a result of a differing number of repeating peptide sequences, called

Answer 28

kringles

Question 29

can exist as either disk-shaped particles | or, more commonly, spherical particles.

Answer 29

HDL

Question 30

believed to represent nascent or newly secreted HDL and is the most active form in removing excess cholesterol from peripheral cells.

Answer 30

Discoidal HDL

Question 31

abnormal lipoprotein present in patients with biliary cirrhosis or cholestasis and in patients with mutations in lecithin–cholesterol acyltransferase (LCAT), the enzyme that esterifies cholesterol.

Answer 31

Lipoprotein X

Question 32

a rate-limiting enzyme | in cholesterol biosynthesis.

Answer 32

HMG-CoA reductase

Question 33

at high doses (~2 to 6 g/d) is also a potent drug for reducing LDL-C levels (by 5% to 25%) and is the only effective drug at this time for significantly raising HDL-C levels (by 15% to 35%).

Answer 33

Niacin or nicotinic acid

Question 34

is a new drug that inhibits the absorption of cholesterol by inhibiting the Niemann-Pick C1-like 1 (NPC1-L1) transporter in the intestine without impacting the absorption of fat-soluble nutrients.

Answer 34

Ezetimibe

Question 35

the lipid abnormality most closely linked to heart | disease.

Answer 35

Hypercholesterolemia

Question 36

associated with genetic abnormalities that predispose affected individuals to elevated cholesterol levels, is called

Answer 36

FH.

Question 37

The principal route of clearance of circulating LDL-C from the blood is __________, a process mediated by binding of LDL-C to LDL-R on the hepatocyte cell membrane.

Answer 37

hepatocyte endocytosis