cholesterol bile salts sphingolipids Flashcards
cholesterol has low solubility in
water
cholesterol is a precursor for ?
bile salts and steroid hormones
in cholesterol synthesis liver makes
bile salts and lipoproteins
in cholesterol synthesis intestine makes
lipoproteins
in cholesterol synthesis reproductive tissue makes
reproductive sex steroids
in cholesterol synthesis all carbons are from
acetyl coa
in cholesterol synthesis NADPH is derived from
hexose monophosphate shunt
cholesterol is synthesized in the ?
cytosol
when dietary chol is high
biosynthesis in liver and intestine is low
when dietary chol is low
biosynthesis in liver and intestine is high
HMG CoA Reductase
3 hydroxy 3 methyl glutaryl
HMG CoA Reductase feedback is inhibited by
chol
HMG CoA Reductase synthesis is repressed by
chol
in HMG CoA Reductase ,insulin does what
stimulate dephos. enzyme
In HMG CoA Reductase glucagon does what
inhibit phos. enzyme
in HMG CoA Reductase thyroid hormone
stimulates regulation
Regulation of Cholesterol synthesis and uptake by extracellular chol. path
LDL binds to mem receptor
LDL is endocytosed as clathrin coated vesicle
3. vesicle lose clathrin and becomes endosome
4. endosome fuse with lyzosomes
5. LDL Receptor separates from endosome and returns to cell surface
6. IN lyzosome: proteins become aa and chol-esters become free chol and FA
In cytosol increased free chol does what to HMGCoA Reductase
supress synthesis and inhibit
in cytosol increased free chol will cause __ increase
ACAT
ACAT?
Free chol + FA creating chol-ester
hypercholesteremia
prevents uptake and intracellular accumulation of chol
atherosclerosis
predisposd by hypercholesteremia
occurs over time
restriction of blood flow that can l;ead to mycocardial infraction or stroke
2 types of hypercholesteremia
dietary and genetic
treatment for hypercholesteremia
drugs that promote bile salt excretions(cholestyramines) and and HMG CoA inhibitors (statin)
