Lipid metabolism Flashcards
(34 cards)
waht is the main store of lipids
adipose tissue
where is adipose found and how much do we have
under skin, around internal organs, 15% men 23% women
what are adipokines
group of hormones, cytokines or cell signalling hormones
what do phospholipids do
form membranes and effect cell signalling
carbs are hydrophilic what are lipids
largely hydrophobic
when does a fatty acids solubility lower
when the fatty acid chain gets longer
phospholipids are amphipathic meaning what
one end hydrophobic, one hydrophilic
majority of lipids of around 90-95% are what
triacylglycerols
what do triacylglycerols serve as
energy store in adipose tissue and muscle
how can triacylglycerol be processed
ingestion, bloodstream, enterocytes, intestinal lumen
what are chylomicrons
a class of lipoprotein, single layer of phospholipid with hydrophobic core, transports insoluble triacylglycerol
what is beta oxidation
catabolic process where fatty acids are broken down
what are the 3 enzymes which allows triacylglycerol breakdown
AGTL (adipose tag lipase), HSL (hormone sensitive lipase), MGL (monoacylglycerol acyltransferase)
in fed state lipolysis:
synthesis > breakdown
in exercise lipolysis:
breakdown > synthesis
what increases within 5-10 mins of exercise
rate of lipolysis
what is involved in 3 step process of FFA’s being activated and transported for degradation
activation (FFAs acitvated by reaction forming acyl-CoA), carnitine binding (carnitine takes acyl group allowing trasnport into matrix), CoA restoration (acyl chain taken from carnitine to reform acyl-CoA
energy yield of beta oxidation
no ATP produced so energetically unfavoured but products (8acetyl coA, 7FADH2 7NADH) enter TCA and ETC
exercise can speed up fatty acid oxidation by
inc blood flow, inc AMP activity, stimulating lipolysis, enhancing translocation of fatty-acid binding
can we convert fatty acid to glucose
no but we can convert glucose to fatty acids
how are free fatty acids transported
carried by albumin
what is structure of triacylglycerol
one glycerol connected to 3 fatty acid by ester bond
hydrolysis of triacylglycerol leads to what
2-monoacylglycerol + 2 fatty acids
where are triacylglycerols stored
in lipid droplets next to mitochondria
