16 Flashcards
(29 cards)
whats long term energy storage source
lipids
how does fat get converted to energy
- TAG goes into diaglycerol via ATGL then to FA and glycerol via hormone sensitive lipase triggered by glucagon and adrenaline increase.
breakdown using lipolysis where FA can be oxidised for energy in oxidisive tissues or converted to ketone bodies in non oxidative tissue
glycerol can be used for glucose synthesis
what triggers hormone sensitive lipase
adrenaline
glucagon
would you still get glycerol and FA if you knock out DAG
yes but less so
how do FA get oxidised
- FA gets acitvated by acetylcoA to fatty acylcoA
- fatty acylcoA goes inside mitochondria via CPT 1 and CPT 2
- beta oxidation to go from fatty acylcoA to acetyl coA and NAD for electron transport chain
how doe acetyl coA activate FA
by attaching coa
how does fattyacyl coa get to mitochondria
via carnitine shuttle
where does beta oxidation are place
mitochondria
what enzymes does beta oxidation of fatty acids (acetylCoa)
acetylcoA dehydrogrenases
where does beta oxidation not happen
brain and rbc
b oxidation removes how many carbons at a time
2
what controls catabolism of FA
the point of control is tranport to mitochondria. CPT inhibited by malonylcoA
whats the level. of CPT1 during starvation
high
bc activated by glucagon
can fats be used for gluconeogeneiss
no but you can use product of beta oxidation which is acetylcoA
ok so how does the body actually make fat
in cytoplasm by adding two carbon units.
in time sof plenty, you have glucose goes to pyruvate… you have a lot of citrate so you can take citrate to cytoplasm where its broken down to acetylcoA
enzyme acetylcoA carboxylase takes you from acCoA to Mal Coa which is then used to add 2 carbon units onto growing FA chains. losing Co2 in the process.
so two stgaes
one is formation of malonylcoa
formation of fatty acid chain
at what stage is fatty acid synthesis controlled
when acetylcoacarboxylase turns acccoa to malonyl
how is acetylcarboxylase controlled
polymerization turns on
phosphorylation (turn off)
long term genetic control
brain doesn’t do beta ox. brain cant use fat. so what happens when there’s no glucose
ketone bodies.
ketone body ancestor
acetylcoa made by beta ox in liver
how are ketone bodies produced
you join acetylcoA and
acetoacetate which makes HMG CoA synthase.
that goes into b hydroxytbu dhkhdjks are then taken to the bood
if well fed. you wont have much HMG CoAsynthesase
how is ketone body production controlled
postranslational modification: acetylation
transcriptionally. FOXA2 and PPARalpha
whats the main regulatory step in ketone body production
making HMG CoA synthase
how are ketone bodies used
converted back to acetylcoa and used for TCA cycle
can liver oxidise so use ketone bodies
no
