Zaidi Lipids

Question 1

what enzyme catalyzes the formation of fatty acids to fatty acyl CoA?

Answer 1

fatty acyl CoA synthetase

Question 2

what does fatty acyl CoA make?

what does this make?

Answer 2

DAG

TG, apolipoproteins, other lipids

Question 3

what is the end result of TG synthesis in the intestine?

Answer 3

chylomicrons

Question 4

what are 2 sources of TG synthesis in the liver?

Answer 4

Glucose via glycolysis

free glycerol

Question 5

conversion pathway of glucose to G3P w/enzymes?

Answer 5

Glucose –> DHAP –> G3P via G3P dehydrogenase

Question 6

enzyme that catalyzes glycerol to G3P?

Answer 6

glycerol kinase

ATP enters, ADP leaves

Question 7

what is the net result of TG synthesis in hepatocytes?

Answer 7

VLDL

Question 8

what are the 2 mechanisms of TG synthesis in adipocytes?

Answer 8

Glucose via GLUT4

chylomicron and VLDL to Fatty Acid

Question 9

what enzyme catalyzes chylomicron and VLDL to fatty acid formation?

Answer 9

capillary lipoprotein lipase

Question 10

what stimulates the formation of fatty acid?

what stimulates the transfer of glucose into the adipocytes through GLUT4?

Answer 10

insulin

Question 11

what is the net result of TG synthesis in adipocytes?

where do they go?

Answer 11

TG

THEY DON’T leave

Question 12

what enzyme breaks down TG into DG?

what is released?

Answer 12

hormone sensitive lipase

Fatty acid

Question 13

what facilitates TG breakdown?

what inhibits it?

Answer 13

glucagon, Epi, Norepi

Insulin

Question 14

DAG to monoacylglycerol is catalyzed by what enzyme?

what is released?

Answer 14

lipoprotein lipase

FA

Question 15

monoacyl glycerol to glycerol is catalyzed by what?

what is released?

Answer 15

monoacyl glycerol lipase

Fatty acid

Question 16

what is required to carry long chain fatty acids?

Answer 16

albumin

Question 17

what are fatty acids broken down to?

via what process?

Answer 17

acetyl CoA

Beta-oxidation

Question 18

what kind of fatty acids are soluble?

Answer 18

short chain (

Question 19

what activates hormone sensitive lipase?

what activates that molecule?

Answer 19

PKA

glucagon and Epi via cAMP and GPCR signaling

Question 20

what inactivates hormone sensitive lipase?

what activates the inhibitor?

Answer 20

protein phosphatase 1 (PP1)

insulin

Question 21

what coats lipid droplets in adipocytes and muscle cells?

Answer 21

perilipin

Question 22

what does perilipin 1 overexpression do?

what regulates it?

Answer 22

inhibits lipolysis

PKA

Question 23

what are synthetic fats (olestra) made of?

Answer 23

sucrose w/6-8 fatty acids

Question 24

describe their absorption

what do they absorb?

what do synthetic fats cause?

Answer 24

not absorbed in s.i.

Vitamins: A, D, E, K

abdominal cramps, bloating, diarrhea

Question 25

what is the function lipoproteins?

Answer 25

transport for cholesterol, TG, fat soluble vitamins | metabolism of lipids

Question 26

what is in the outer shell of lipoproteins

Answer 26

similar to phospholipid bilayer (has cholesterol, apolipoproteins)

Question 27

what is in the inner core of lipoproteins?

Answer 27

hydrophobic TGs, cholesterol esters

Question 28

what enzyme catylzes cholestero --> cholesterol ester?

Answer 28

acetyl CoA cholesterol acyltransferase (ACAT)

Question 29

what are the properties of a chylomicron?

Answer 29

largest, least dense, high TG, exogenous, from dietary fats

Question 30

what do chylomicrons have?

Answer 30

ApoB-48 ApoE ApoC-II BEC 48

Question 31

what do VLDLs contain?

Answer 31

ApoB-100 ApoE ApoC-II BEC 100

Question 32

what do IDLs contain?

Answer 32

ApoB-100 Apo-E BE 100

Question 33

what do LDLs contain?

Answer 33

ApoB-100

Question 34

what do HDLs contain?

Answer 34

ApoA-I ApoC-II Apo-E ACE

Question 35

HDL properties?

Answer 35

smallest most dense high protein and phospholipid content

Question 36

What are the 3 main roles for Apolipoproteins?

Answer 36

structural transport cofactors for enzymes

Question 37

What is type I hyperlipoproteinemia? what is the effect?

Answer 37

familial hyperchylomicronemia deficiency in apoC-II or defective LPL INC chylomicrons, INC TGs

Question 38

What is type II hyperlipoproteinemia? what are the effects?

Answer 38

familial hypercholesterolemia LDL receptor completely defective (IIa) or partially defective (IIb) INC cholesterol, INC LDL, in IIb INC TG and VLDL

Question 39

What are the clinical symptoms of type I hyperlipoproteinemia? what is the plasma TAG level? treatment?

Answer 39

abdominal pain, acute pancreatitis, cutaneous eruptive xanthomas >1000 mg/dL low fat diet

Question 40

in type II hyperlipoproteinemia the ability to recognize what is impaired? what are the physical symptoms? what are cholesterol levels of hetero and homo?

Answer 40

ApoB 100 on LDL xanthomas, arcus senilis or corneal deposits in eye, angina pectoris hetero: 300-500, homo > 800

Question 41

Outline the steps in chylomicron processing

Answer 41

Nascent chylomicron (ApoB-48) -->(add ApoC-II and ApoE) to make mature chylomicron --> (capillary LPL) and ApoC-II leaves --> chylomicron remnant (B and E left)

Question 42

outline the steps in VLDL, IDL, and LDL processing

Answer 42

start with VLDL ---> (lose ApoC-II) via capillary LPL to make: IDL ---> lose ApoE via hepatic LPL to make: LDL

Question 43

where are HDLs made?

Answer 43

liver and small intestine

Question 44

outline the steps in HDL processing

Answer 44

nascent HDL --> HDL w/ApoA-1 -->(via LCAT) HDL, from there is can exchange with the other lipoproteins

Question 45

what is the rate limiting step for cholesterol biosynthesis? what drug blocks this enzyme?

Answer 45

HMG CoA Reductase statins

Question 46

what does HDL do that is beneficial? antihypercholestermic drugs increase what? how do you increase HDL levels?

Answer 46

reverse cholesterol transport from peripheral tissues to liver INC HDL-C weight loss, exercise, stop smoking, drink a little

Question 47

what product to statins prevent from forming during cholesterol biosynthesis?

Answer 47

Mevalonate

Question 48

what does the lymphatic system play a role in? what do LNs do?

Answer 48

digestive and immune functions trap and destroy circulating cancer cells

Question 49

what are the sources of TGs?

Answer 49

dietary processed in intestine de novo in hepatocytes de novo in adipocytes