Cholesterol Flashcards
What is cholesterol a basis for?
steroid hormones, bile salts
How is vitamin D synthesised?
cholesterol and UV
When are bile salts generated and stored?
generated by liver and stored in gallbladder
Why are lipids packaged into lipoproteins?
lipids are insoluble so lipoproteins make them hydrophilic and add recognition molecules for cells
What are lipid rafts?
areas of the plasm membrane that have high concentrations of cholesterol and sphingolipids
How is cholesterol linked to the hedgehog signalling protein? Importance?
covalently attached to the N-terminal fragment during processing
limits diffusion within tissues, key for limb formation
What is bile salt function?
emulsify TAGs
What are the products of lipases?
MAG, DAG, FA
What are micelles made up of?
MAG/DAG/FA, bile salts, cholesterol and fat soluble vitamins
What cells absorb micelles and where are they located?
enterocytes and SI
What happens once micelles are reabsorbed?
TAGs are resynthesised and incorporated into chylomicrons
How are chylomicrons transported?
lymphatics system then bloodstream
What happens to chylomicrons at target endothelial cell?
encounter lipoprotein lipase, catalyses TAGs to glycerol and FA
How is lipoprotein lipase activated?
C-11 apoprotein in chylomicron
What happens to FA and glycerol?
FA undergoes beta-oxidation, glycerol returned to liver for gluconeogenesis
