Lecture 15: Lipid Metabolism and Pathways Flashcards
where does beta oxidation of fatty acids occur
- mitochondria
- peroxisomes
which carrier protein transfers the acyl groups across the mitochondrial membrane
carnitine carrier protein
what is produced in each cycle of beta oxidation
1 NADH
1 FADH2
1 acetyl-CoA
a mutation in which enzymes has a link to causing SIDS
acyl-CoA dehydrogenase involved in the first step of beta oxidation
where does fatty acid synthesis happen
cytosol of:
- liver
- adipocytes
what is the rate limiting step in beta oxidation
transfer of acyl CoA into mitochondria
what is the rate limiting step in fatty acid synthesis
formation of malonyl CoA from acetyl-CoA, catalysed by acetyl CoA carboxylase
roles of cholesterol
- source of bile acids
- precursor of steroid hormones
what catalyses esterification of cholesterols
cholesterol acyltransferases
what is the rate limiting step in cholesterol biosynthesis
HMG Co-A reductase converting HMG CoA to mevalonate
what is the target site for statin drugs
HMG CoA reductase
what are the intermediates in cholesterol biosynthesis
- 2C acetyl CoA
- HMG CoA
- 6C mevalonate
- 30C squalene
- 27C cholesterol
how are short chain fatty acids transported in the blood
bound to blood proteins like albumin
how are neutral insoluble lipids transported
in the central core of lipoproteins
what are chylomicrons used for
dieatry TGL transport to muscle and adipose tissue
what are VLDLs used for
endogenous TGL transport from liver to tissues
what are LDLs used for
cholesterol transport from liver to tissues
what are HDLs used for
reverse cholesterol transport, from tissues to liver to remove cholesterol
how do chylomicrons and VLDL particles give up lipid to tissues
action of tissue bound lipases
how are remnants of chylomicrons and VLDLs taken up
liver recognises ApoE content of the remnants and takes them up for recycling
what apoprotein do LDL particles contain
ApoB-100
what is expression of LDL receptors controlled by
- SREBPs
- PCSK9
