lecture 24 - absorption and transport of fats Flashcards
two examples of molecules associated with fat metabolism
triacylglycerol and cholesterol ester
what are bile salts synthesised from and where
synthesised from cholesterol in the liver and stored in the gallbladder
what are bile salts secreted in response to
cholecystokinin (CCK)
what does the hormone secretin do
stimulates secretion of alkaline bile and pancreatic fluids in response to HCL in the duodenum
what does pancreatic lipase hydrolyse triacylglycerols to and why
free fatty acids and 2-monoacylglcerol
= because the ester linkage of R1 ans R3 can be hydrolysed but R2 can’t
what is the hydrophilic / hydrophobic parts of a micelle
hydrophobic core and hydrophilic parts facing outwards
what is fat malabsorption caused by and what can it cause
caused by conditions that interfere with bile or pancreatic lipase secretion
= leads to excess of fat and fat soluble vitamins in faeces
what do lipoproteins do
help ‘solubilise’ lipids for transport in blood to tissues
- provide a ‘delivery system’ for transporting lipids into and out of cells
what are the functions of apoproteins
- structural for assembly
- ligands for cell surface receptors
- enzyme cofactors
which lipoprotein has the highest protein composition
HDL
which lipoprotein has the highest triacylglycerol composition
chylomicrons
which lipoprotein has the highest cholesterol composition
LDL
how can you estimate someones LDL
total cholesterol - HDL - triglyceride / 5
how can someones VLDL be estimated
triglyceride / 5
what are the two lipid transport pathways and what do they include
exogenous = chylomicron pathway
- brings dietary lipids in and disperses it to body and the remainders to the liver
endogenous = VLDL / LDL pathway
- endogenously synthesised fat
