Lipid Uptake and Synthesis

Question 1

What does pancreatic lipase do?

Answer 1

Breaks apart triacylglycerol into 2 fatty acids and monoacylglycerol

Question 2

What drug is a reversible inhibitor of pancreatic lipase?

Answer 2

Orlistat (OTC = xenical, alli)

Question 3

What is a common side effect of pancreatic lipase inhibitory drugs? ir orlistat, xenical, alli, …

Answer 3

Unable to absorb fat soluble vitamins like A, D, E, and K

Question 4

What are the main two functions of Cholestyramine?

Answer 4

Removes bile acids, which stimulates liver bile acid synthesis from cholesterol.
Stimulates LDL receptor in liver causing reduced serum cholesterol

Question 5

Secretion of pancreatic enzymes occurs in response to what gut hormone?

Answer 5

cholecystokinin

Question 6

What is the primary function of bile salts?

Answer 6

To aide in digestion by forming micelles to package long and very long chain fatty acids

Question 7

What are the 5 major lipoproteins that enable fats and cholesterol to move within the water-based bloodstream?

Answer 7

chylomicrons, IDL, HDL, VLDL, LDL

Question 8

Where are chylomicrons produced?

Answer 8

Intestinal epithelia

from dietary fat

Question 9

Where are VLDLs produced?

Answer 9

In liver mainly from dietary CHO

Question 10

Where are IDLs produced?

Answer 10

In the blood after Triacylglycerol digestion

VLDL remnant

Question 11

Where are LDLs produced?

Answer 11

In the blood after triacylglycerol digestion
Remnant of IDL
End product of VLDL

Question 12

Where are HDLs produced?

Answer 12

Liver and Intestine

Question 13

What are the two major functions of HDLs?

Answer 13

Exchanges proteins and lipids with other lipoproteins

returns cholesterol from peripheral tissues to liver

Question 14

What are the most and least dense lipoproteins?

Answer 14

Chylomicrons = least dense
HDL = most dense

Question 15

Why are certain lipoproteins more dense than others?

Answer 15

The ones with more proteins relative to TG are more dense

Question 16

What major apolipoproteins are found in VLDLs?

Answer 16

B-100
C-II
E

Question 17

What major apolipoproteins are found in chylomicrons?

Answer 17

B-48
C-II
E

Question 18

What major apolipoproteins are found in LDLs?

Answer 18

B-100

Question 19

What major apolipoproteins are found in HDLs?

Answer 19

A-1
C-II
E

Question 20

What two apolipoproteins are encoded on the same gene? A difference in mRNA encoding determines which is produced

Answer 20

B-48

B-100

Question 21

Where is apoB-48 produced?

Answer 21

intestine

Question 22

Where is apoB-100 produced?

Answer 22

liver

Question 23

What is lipoprotein lipase activated by?

Answer 23

ApoCII

Question 24

Lipoprotein Lipase is anchored to capillary walls of most tissues by?

Answer 24

Heparin sulfate

Question 25

What stimulates the synthesis and secretion of adipose isoenzyme of lipoprotein lipase?

Answer 25

insulin

Question 26

Where does the synthesis of lipids primarily occur?

Answer 26

In the liver

Question 27

How does acetyl CoA get out of mitochondria?

Answer 27

It is changed into citrate

Question 28

What are the two major ingredients for fatty acid synthesis?

Answer 28

cytosolic acetyl CoA | NADPH

Question 29

What is an important cofactor for acetyl CoA carboxylase?

Answer 29

Biotin

Question 30

What does acetyl CoA Carboxylase do?

Answer 30

Produces Malonyl CoA from Acetyl CoA | uses ATP

Question 31

What enzyme sequentially adds 2C units from malonyl CoA to the growing fatty acid chain?

Answer 31

Fatty Acid Synthase Complex

Question 32

Oxidation of new fatty acids in mito after they are synthesized is prevented by inhibition of _________ by ___________

Answer 32

carnitine palmitoyltransferase (CPT1) by malonyl CoA

Question 33

Where does the elongation of fatty acids occur?

Answer 33

ER

Question 34

What organ makes especially long fatty acids?

Answer 34

Brain (C22 to C24)

Question 35

What is the end product of fatty acid synthesis?

Answer 35

Palmitate (C16)

Question 36

In the elongation of Fatty acids, the fatty acyl chain attached to __________ instead of ACP

Answer 36

Coenzyme A

Question 37

Where does desaturation of fatty acids occur?

Answer 37

In the ER

Question 38

What is required for the desaturation of fatty acids?

Answer 38

molecular oxygen

Question 39

What is the main storage form of fatty acids?

Answer 39

triacylglycerols

Question 40

What enzyme in the TG synthesis process is found in the liver but not in adipose tissue? converts glycerol to glycerol-3-phosphate

Answer 40

glycerol kinase

Question 41

Fatty acid synthase makes palmitate, that can be _________ and _________

Answer 41

elongated | desaturated

Question 42

What stimulates the synthesis and secretion of lipoprotein lipase?

Answer 42

Insulin

Question 43

What enzyme breaks down TGs to FAs for release by adipose tissue?

Answer 43

Hormone sensitive Lipase

Question 44

What is the key intermediate in phospholipid synthesis from fatty acids?

Answer 44

CDP-serine intermediate

Question 45

Which fatty acid of phospholipids tends to be unsaturated?

Answer 45

C2 position

Question 46

What is the general class of enzymes that cleave phospholipids at different locations on the molecule?

Answer 46

phospholipase

Question 47

Phospholipase A2 cleaves phospholipids in the membrane for ________ synthesis?

Answer 47

prostaglandin

Question 48

What type of fatty acid derivative is important for the myelin sheath on nerve cells? and are the antigenic determinants for the ABO blood groups

Answer 48

sphingolipids