Lipids and Lipoproteins Flashcards
What enzyme exclusive to the liver can convert glycerol to glycerol 3-Phosphate?
Glycerol kinase
Does hormone sensitive lipase like to be phosphorylated?
(Is it activated or deactivated by phosphorylation?)
Yes. Hormone sensitive lipase is activated by phosphorylation.
What apoprotiens do we see on LDL lipoproteins?
ApoB-100
What vesicle does the liver use to export new triacylglycerols?
VLDLs
What enzyme catalyzes the rate limiting step of cholesterol biosyntehsis?
HMG CoA reductase
What enzyme breaks down TAGs in the adipocytes?
Hormone sensitive lipase
What apoprotiens do we see on HDL lipoproteins?
ApoA-1
ApoE
ApoC-II
What hormones positively affect hormone sensitive lipase?
What hormone negatively affects hormone sensitive lipase?
Glucagon
Epinephrine
Norepinephrine
Insulin negatively impacts hormone sensitive lipase
What two targets are phosphorylated by Protein Kinase A in the mobilization of fatty acids?
What hormones use protein kinase A in this pathway?
Targets:
Hormone sensitive lipase
Perilipin
Hormones that use PKA:
Epinephrine / Norepinephrine
Glucagon
What apoprotiens do we see on Chylomicrons?
ApoB-48
ApoE
ApoC-II
What apoprotiens do we see on IDL lipoproteins?
ApoB-100
ApoE
What enzyme breaks down VLDLs and Chylomicrons into free fatty acids for transport into the adipocyte?
Capillary lipoprotein lipase
What apoprotiens do we see on VLDL lipoproteins?
ApoB-100
ApoE
ApoC-II
How much energy on average is stored in TAGs for a roughly 150 lb man?
100,000 kCal
Besides creating them de novo, where do adipocytes get free fatty acids?
From VLDLs from the liver, and chylomicrons from the intestines.
Why does an increase in excess glucose make you fat?
Because in the liver, glucose is converted into glycerol 3-P and fatty acids, then put together to make triacylglycerols that are shipped to adipocytes.
What is the function of ApoC-II?
Activates Capillary lipoprotein lipase
What is the function of ApoE?
Assits with uptake into the liver
What is the function of ApoA-I?
Activates an enzyme that turns cholesterol into cholesterol ester.
What lipoprotein helps with the maturation of chylomicrons?
HDL
What enzyme converts cholesterol into cholesterol ester for HDL?
Lecithin-cholesterol acyltransferase
What is the basic pathology of Type 1 Hyerlipoproteinemia?
There is an increase in the number of chylomicrons in the blood due to an inability to process TAGs. This can be due to either a defect in capillary lipoprotein lipase, or in ApoC-II which activates it.
