Lipids

Question 1

What do intestinal enterocytes make from broken down fats

Answer 1

Chylomicrons (90% TG)

Question 2

Where do chylomicrons go once made

Answer 2

Lymphatic system –> thoracic duct–> blood

Question 3

What is required for transport of chylomicrons out of the small intestine

Answer 3

Apo B48

Question 4

What happens if not enough Apo B48

Answer 4

Abetalipoproteinemia

Question 5

What do cells use to draw free FFA’s from circulating chylomicrons

Answer 5

Lipoprotein Lipase

Question 6

What does liver do with chylomicron remnat

Answer 6

Makes VLDL

Question 7

What does Apo B 100 do

Answer 7

Helps secrete VLDL that was made in the liver

Question 8

What happens if not enough Apo B 100

Answer 8

VLDL cannot leave liver

Question 9

What is VLDL transformed to as FFA’s are taken up by cells

Answer 9

IDL

Question 10

What is IDL degraded to and by what?

Answer 10

LDL, by hepatic triglyceride lipase - made in liver

Question 11

What is LDL rich in

Answer 11

Cholesterol - lost FFA’s

Question 12

What happens if LDL oxidized

Answer 12

Atheroma

Question 13

How do cells absorb LDL

Answer 13

By endocytosis, using clathrin coated pit, LDL receptor

Question 14

What can cells do if they have too much cholesterol

Answer 14

Deposit it in circulating HDL from liver

Question 15

What is LCAT

Answer 15

HDL uptakes cholesterol from cells this way

Question 16

What can HDL deposit cholesterol on? By what enzyme?

Answer 16

VLDL or LDL via CETP

Question 17

What is SRB1

Answer 17

Scavenger receptor - for hepatocyte to pull cholesterol off HDL

Question 18

Apo B48

Answer 18

Chylomicron secretion from enterocyte to lymphatic system

Question 19

Apo B100

Answer 19

Found on VLDL, IDL, and LDL that have left the liver

Question 20

Apo E

Answer 20

Mediate extra remnant uptake

Question 21

Apo A-1

Answer 21

Activates LCAT, found on HDL

Question 22

Apo C-II

Answer 22

Cofactor for LPL

Question 23

What is deficient in Abetalipoproteinemia

Answer 23

AR, deficiency in Apo-B48 and ApoB-10

Mutation in MTP gene

Question 24

Presentation of abetalipoproteinemia

Answer 24

Presents in first few months of life with FTT, steatorrhea, impaired transport of fat soluble vitamins (ADEK), acanthocytosis (misshapen RBC membrane bc of bad lipids), ataxia, night blindness

Question 25

Treatment of abetalipoproteinemia

Answer 25

Vitamin E

Question 26

What is defective in Type 1 Hyperchylomicronemia

Answer 26

AR Deficiency of LPL Or, Defective Apolipoprotein CII (LPL cofactor)

Question 27

Presentation of Type 1 Hyperchylomicronemia

Answer 27

Pancreatitis, HSM, xanthomas | No incr risk of atherosclerosis

Question 28

What is elevated in the blood in Type 1 Hyperchylomicronemia

Answer 28

Chylomicrons, TG, Cholesterol

Question 29

What is defective in Type IIa Familial hypercholesterolemia

Answer 29

AD | Absent/decreased LDL receptor - needed for uptake of circulating LDL

Question 30

Presentation Type IIa Familial hypercholesterolemia

Answer 30

Tendinous xanthomas Corneal arcus Accelerated Atherosclerosis

Question 31

What is defective in Type IV hypertriglyceridemia

Answer 31

AD | Overproduction of VLDL in liver

Question 32

What is elevated in blood in Type IV hypertriglyceridemia

Answer 32

VLDL and TG

Question 33

Presentation of type IV hypertriglyceridemia

Answer 33

Pancreatitis

Question 34

What is increased in blood in type IIa familial hypercholesterolemia?

Answer 34

LDL and cholesterol

Question 35

What is the substrate for making cholesterol in the body?

Answer 35

Acetyl CoA

Question 36

Rate limiting enzyme of cholesterol synthesis

Answer 36

HMG-CoA reductase

Question 37

What is the main precursor in FA synthesis

Answer 37

Acetyl CoA

Question 38

Where does FA synthesis take place

Answer 38

Cytoplasm of hepatocytes

Question 39

Rate limiting enzyme of FA synthesis

Answer 39

Acetyl-CoA carboxylase

Question 40

Where does FA degradation take place

Answer 40

Mitochondria

Question 41

What is rate-limiting enzyme of FA degradation (beta-oxidation)

Answer 41

Carnitine acyltransferase-1

Question 42

What happens if deficient in CAT-1?

Answer 42

Can't get long chain FA into mt --> accum in cytoplasm. And can't be broken down.

Question 43

Activates LCAT

Answer 43

Apo A-1

Question 44

LCAT

Answer 44

Catalyzes esterification of cholesterol

Question 45

Mediates chylomicron secretion

Answer 45

Apo B-48

Question 46

Mediates VLDL secretion

Answer 46

Apo B-100

Question 47

Apoprotein that Binds LDL receptor

Answer 47

Apo B-100

Question 48

Cofactor for lipoprotein lipase

Answer 48

Apo C-II

Question 49

Mediates uptake of remnant particles

Answer 49

Apo E

Question 50

Rate limiting enzyme for ketone body synthesis

Answer 50

HMG-CoA synthase