Lipids

Question 1

What is a saturated fatty acid?

Answer 1

• maximum # of H bonds
• only single bonds

Question 2

What is an unsaturated fatty acid?

Answer 2

• “missing” H atoms
• double bonds
• cis or trans configuration

Question 3

What happens in desaturation of fatty acids?

Answer 3

insertion of a double bond and removal of 2 Hs

Question 4

What happens in elongation of fatty acids?

Answer 4

2 carbons added at carboxyl end

Question 5

What is/are the enzyme(s) that are used in the desaturation of linoleic acids

Answer 5

• delta-6 desaturase
• delta-5 desaturase

Question 5

what are the enzyme(s) used in elongation of linoleic acid?

Answer 5

elongase-5

Question 6

what are eicosanoids?

Answer 6

• metabolites of 20-carbon fatty acids
• produced by most cells in the body
• hormone-like, but function locally (only on what it’s produced by)
• ie: prostaglandins, thromboxanes, leukotrienes

Question 7

What is the main dietary and storage lipid?

Answer 7

triglycerides

Question 8

Where are lipids digested and by what?

Answer 8

• mouth - lingual lipase
• stomach - gastric lipase
• small intestine - pancreatic lipase and cholesterol esterase

Question 9

What do bile acids do?

Answer 9

emulsify digested lipids

Question 10

what system do digested lipids go to?

Answer 10

lymph

Question 11

What is the “good” type of lipoprotein?

Answer 11

high density lipoprotein (HDLs)

Question 12

what is the “bad” type of lipoprotein?

Answer 12

Low density lipoproteins (LDLs)

Question 13

more ____ and less ____ makes a higher density lipoprotein

Answer 13

protein; fat

Question 14

_____ hydrolyzes the triglycerides in chylomicrons into _____ and 2 _____

Answer 14

LPL (lipoprotein lipase); 2-MAG; fatty acids

Question 15

What are chylomicrons referred to as when they become triglyceride-depleted

Answer 15

chylomicron remnant

Question 16

how are chylomicron remnants removed from circulation?

Answer 16

through ApoE-mediated interactions with a receptor in the liver

Question 17

How is LPL activated in chylomicrons

Answer 17

by ApoC

Question 18

What is reverse cholesterol transport?

Answer 18

when HDL picks up cholesterol around the body and brings it to the liver

Question 19

what is the main transporter of newly synthesized hepatic TAG?

Answer 19

VLDL

Question 20

What are the fates of cholesterol in the liver?

Answer 20

1. converted into bile acids to replenish the bile acid pool
2. secreted “as is” directly with bile, to be eliminated in feces
3. Packaged into VLDL and sent around the body

Question 21

higher HDL levels means more ____ returning to the _____

Answer 21

cholesterol; liver

Question 22

The complete breakdown of TAG molecule releases 1 _____ and 3 ______

Answer 22

glycerol; fatty acids

Question 23

What protein is only present in chylomicrons?

Answer 23

ApoB-48

Question 24

what protein is only present in LDLs and VLDLs?

Answer 24

ApoB-100

Question 25

What protein is only present in HDLs?

Answer 25

ApoA