Lecture 7 - Lipids Flashcards
Where are lipids soluble
in organic solvents like ether, chloroform, acetone
What are the two physical configurations of fatty acids
saturated and unsaturated
What are the two systems for naming fatty acids
delta and omega systems
What are the signs of an n-6 fatty acid deficiency
dermatitis, lowered growth, lowered reproductive maturity
What are the signs of an n-3 fatty acid deficiency
lowered IQ from delayed CNS development, and lowered vision from delayed retinal development
How can essential fatty acids be desaturated
insert a double bond and remove 2H
How can essential fatty acids be elongated
add 2 carbons
What are eicosanoids
metabolites of 20-carbon fatty acids
Where are eicosanoids produced
by most cells in the body
What role do eicosanoids play in the body
they’re hormone-like but function locally, playing a role in inflammation, platelet aggregation and blood pressure
What is the main dietary lipid
triglycerides
What are triglycerides critical for
lipogenesis
lipolysis
transported in lipoproteins
What are the structures of triglycerides
monoacylglycerol (MAG)
diacylglycerol (DAG)
triacylglycerol (TAG)
What are phospholipids
hydrophilic head groups in membranes
What are sterols
steroid alcohols
- essential components of membranes
What are good sources of cholesterol
meat and eggs
What starts lipid digestion in the mouth
lingual lipase
What digests lipids in the stomach
gastric lipase
What produces bile and what stores it
made in liver, stored in gallbladder
What kind of enzymes continue lipid digestion in the small intestine
pancreatic enzymes such as pancreatic lipase and cholesterol esterase
What is the role of bile in digesting fats
emulsify the fats turning them into micelles, which are small complexes containing lipid digestions products and bile salts
Where do bile salts go once fats have been digested
95% reabsorbed and recycled back to liver
(5% lost in feces)
What are the enzymes in the brush border
pancreatic lipase
cholesterol esterase
phospholipase
Which lipoproteins are considered bad
VLDL, IDL, and LDL
Which lipoprotein is considered good
HDL
Why is HDL considered good lipoprotein
high protein low lipid
When do chylomicrons increase in the body
after a meal
What is the function of lipoprotein lipase and where is it found
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
What is the main transporter of newly synthesized hepatitic TAG
VLDL
How is HDL transported around the body
cholesterol is esterified onto HDL
What is reverse cholesterol transport
when HDL picks up cholesterol around the body and brings it to liver
What are the fates of cholesterol in the liver
- converted into bile acids to replenish the bile acid pool
- secreted “as is” directly with bile, to be eliminated in feces
- packaged into VLDL and sent around body
Why is higher HDL good
because that means more cholesterol back to the liver
Where do lipids fall into gluconeogenesis
the glycerol backbone is glycogenic
Where do lipids fall into the Krebs cycle
fat oxidation via acetyl CoA
The breakdown of TAG releases…
1 glycerol and 3 fatty acids
Each round of B-oxidation removes 2 carbons and produces…
1 NADH and 1 FADH2
Protein is ____% of daily calories
10-35%
Carbs are ______% of daily calories
45-65%
Fats are ____% of daily calories
20-35%
How are industrial trans fats produced
hydrogenation of vegetable oils
What is partial hydrogenation
results in double bonds being converted from cis to trans
What is complete hydrogenation
results in all double bonds becoming fully saturated
Trans fats are naturally found in ______________ fats
ruminant fats
What would be seen in fat levels with a high consumption of trans fats
increased LDL
increased LDL cholesterol
increased inflammation
decreased HDL cholesterol
High intake of trans fats would be related to increased risk of…
CVD
