Cholesterol Flashcards
LDL
- Delivers cholesterol to various organs
- High Cholesterol/ Triacylglyceride Ratio
- Major Apoliprotein : Apro B-100
- Cause plaques in blood vessels
Cholesterol
Lipid
Isoprenoid
steroid
3 six carbon ring + 1 five carbon ring
synthesized from acetyl coA
Statins
inhibit HMG-CoA reductase
reduce cholesterol levels
Inhibitors of HMG-CoA reductase
- Cholesterol
- Glucagon
- Bile Acid
- Mevalonate
What is the activated carrier needed for cholesterol synthesis
CoA
Functions of Lipoproteins
transport lipids in blood
four main classes of lipoproteins
Chylomicrons
VLDL
LDL
HDL
Lipases
hydrolyze the triacylglyceride being delivered into fatty acids and glycerol
Bile Acid
- Cholesterol Excreition
- Emulsification of lipids in the intestine
- increase lipase activity in the intestine
- Produced in the liver -> gallbladder(stored)
Lipoproteins has higher cholesterol content relative to triacylglycerol content:
HDL
LDL
Lipoproteins deliver lipids to the liver
Chylomicron
HDL
LDL
Lipoproteins delivers lipids to peripheral (non-liver) cells
Chylomicron
VLDL
LDL
Clofibrate
- lipid-lowering agent used for controlling the high cholesterol and triacylglyceride level in the blood.
- It increases lipoprotein lipase activity to promote the conversion of VLDL to LDL, and reduce the level of VLDL.
- It can increase the level of HDL as well
Ezetimibe
- reduces blood cholesterol levels by inhibiting the absorption of cholesterol by the intestine by blocking uptake
CETP (cholesterol ester transfer protein )
- exchanges the cholesterol esters in the HDL for triglycerides from LDL
- HDL3 becomes HDL2
Apoproteins
- Direct Lipoproteins to correct cell
- Activate Lipases associated with the target cell
Atheroschelerosis
Plaque formation due to high LDL levels in the blood
Chylomicrons
- highest TG:Cholesterol
- Made in small intestine
- enter virculation ia lymphaytic system.
- Transport dietary cholesterol and TG to the rest of the body (including liver)
- ApoB 48 is exclusive
- remnants are endocytosed by liver
VLDL
Made in liver
transport lipids from liver to peripheral cells
HDL
- made in liver and small intestine
- Majorly apoA-I
- Cardio Protective via RTC
- Anti inflammatory, anti oxidant (GSH peroxidase), vasodilatory effects
- Transport excess Cholesterol from peripheral tissues back to liver for excretion
Gallstones
excessive amounts of cholesterol in bile can result in formation of gallstones.
LCAT
Lecithin-Cholestrol Acylltransferase
esterify apoA-I cholesterol -> HDL3 particles
Generate cholesterol esters
