Lecture 7 - Lipids

Question 1

Where are lipids soluble

Answer 1

in organic solvents like ether, chloroform, acetone

Question 2

What are the two physical configurations of fatty acids

Answer 2

saturated and unsaturated

Question 3

What are the two systems for naming fatty acids

Answer 3

delta and omega systems

Question 4

What are the signs of an n-6 fatty acid deficiency

Answer 4

dermatitis, lowered growth, lowered reproductive maturity

Question 5

What are the signs of an n-3 fatty acid deficiency

Answer 5

lowered IQ from delayed CNS development, and lowered vision from delayed retinal development

Question 6

How can essential fatty acids be desaturated

Answer 6

insert a double bond and remove 2H

Question 7

How can essential fatty acids be elongated

Answer 7

add 2 carbons

Question 8

What are eicosanoids

Answer 8

metabolites of 20-carbon fatty acids

Question 9

Where are eicosanoids produced

Answer 9

by most cells in the body

Question 10

What role do eicosanoids play in the body

Answer 10

they’re hormone-like but function locally, playing a role in inflammation, platelet aggregation and blood pressure

Question 11

What is the main dietary lipid

Answer 11

triglycerides

Question 12

What are triglycerides critical for

Answer 12

lipogenesis
lipolysis
transported in lipoproteins

Question 13

What are the structures of triglycerides

Answer 13

monoacylglycerol (MAG)
diacylglycerol (DAG)
triacylglycerol (TAG)

Question 14

What are phospholipids

Answer 14

hydrophilic head groups in membranes

Question 15

What are sterols

Answer 15

steroid alcohols
- essential components of membranes

Question 16

What are good sources of cholesterol

Answer 16

meat and eggs

Question 17

What starts lipid digestion in the mouth

Answer 17

lingual lipase

Question 18

What digests lipids in the stomach

Answer 18

gastric lipase

Question 19

What produces bile and what stores it

Answer 19

made in liver, stored in gallbladder

Question 20

What kind of enzymes continue lipid digestion in the small intestine

Answer 20

pancreatic enzymes such as pancreatic lipase and cholesterol esterase

Question 21

What is the role of bile in digesting fats

Answer 21

emulsify the fats turning them into micelles, which are small complexes containing lipid digestions products and bile salts

Question 22

Where do bile salts go once fats have been digested

Answer 22

95% reabsorbed and recycled back to liver
(5% lost in feces)

Question 23

What are the enzymes in the brush border

Answer 23

pancreatic lipase
cholesterol esterase
phospholipase

Question 24

Which lipoproteins are considered bad

Answer 24

VLDL, IDL, and LDL

Question 25

Which lipoprotein is considered good

Answer 25

HDL

Question 26

Why is HDL considered good lipoprotein

Answer 26

high protein low lipid

Question 27

When do chylomicrons increase in the body

Answer 27

after a meal

Question 28

What is the function of lipoprotein lipase and where is it found

Answer 28

LPL is activated by ApoC in chylomicrons and hydrolyzes the TAG in chylomicrons - LPL is located on the surface of endothelial cells lining small blood vessels and capillaries

Question 29

What is the main transporter of newly synthesized hepatitic TAG

Answer 29

VLDL

Question 30

How is HDL transported around the body

Answer 30

cholesterol is esterified onto HDL

Question 31

What is reverse cholesterol transport

Answer 31

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

Question 32

What are the fates of cholesterol in the liver

Answer 32

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 body

Question 33

Why is higher HDL good

Answer 33

because that means more cholesterol back to the liver

Question 34

Where do lipids fall into gluconeogenesis

Answer 34

the glycerol backbone is glycogenic

Question 35

Where do lipids fall into the Krebs cycle

Answer 35

fat oxidation via acetyl CoA

Question 36

The breakdown of TAG releases...

Answer 36

1 glycerol and 3 fatty acids

Question 37

Each round of B-oxidation removes 2 carbons and produces...

Answer 37

1 NADH and 1 FADH2

Question 38

Protein is ____% of daily calories

Answer 38

10-35%

Question 39

Carbs are ______% of daily calories

Answer 39

45-65%

Question 40

Fats are ____% of daily calories

Answer 40

20-35%

Question 41

How are industrial trans fats produced

Answer 41

hydrogenation of vegetable oils

Question 42

What is partial hydrogenation

Answer 42

results in double bonds being converted from cis to trans

Question 43

What is complete hydrogenation

Answer 43

results in all double bonds becoming fully saturated

Question 44

Trans fats are naturally found in ______________ fats

Answer 44

ruminant fats

Question 45

What would be seen in fat levels with a high consumption of trans fats

Answer 45

increased LDL increased LDL cholesterol increased inflammation decreased HDL cholesterol

Question 46

High intake of trans fats would be related to increased risk of...

Answer 46

CVD