Fatty Acid and TAG Catabolism Flashcards
what are the 2 lipases of F.A?
Hormone sensitive lipases and lipoprotein lipases
hormone sensitive lipases ?
release fatty acid from adipose for energy
lipoprotein lipases
release FA from lipoproteins for storage in adipose & usein other tissues
LPL diffuse into ?
inside adipose tissue cells..TAGs are resynthesized and stored for energy
HSL diffuse into ?
plasma and bind to abumin and are taken ti liver and degraded for energy
Activation of HSL
Primary msg (Glucagon, epinephrine, ACTH) bind to membrance receptor adenyl cyclase is activated cAMP increases Protein kinase activated Phosphorylates "activates" HSL
what inhibits HSL ?
Insulin by dephosphorylation
activation of LPL
Apolipoprotein C2 is on surface of lipoprotein
LPL is on endothelial surface (in adipose, cardiac and skeletal m.)
when Lipoprotein gets close to surface Apo CII associates with LPL Causing it to become active
chylomicrons
Transport dietary lipid from intestine to adipose
Lipoproteins
Transport lipid between liver and other tissues.
albumin
transport Fatty Acids from adipose to liver
ketone bodies
Transported in solution in plasma. (i.e. from liver to skeletal + cardiac tissues)
VLDL
Primarily transports—–TAG from liver to adipose and other tissues (also taken up by liver)
~95% lipid….apo C-II, C-III, B-100, E
LDL and Composition
Primarily transports——- cholesterol to tissues (also taken up by liver)
~80% lipid….apo C-II, C-I, B-100, E
HDL and composition
Primarily transports——- cholesterol from tissues to liver
IDL and composition
Primarily transports——– cholesterol to tissues via conversion to LDL (also taken up by liver)
~80% lipid….apo C-II, C-III, B, E
net energy yield from palmitate beta oxidation
7NADH –>10.5 ATP
7FADH2–>17.5 ATP
8 ACETYL CoA –>80 ATP
Subtotal 108 ATP
CAT 1 are inhibited by
malonyl CoA which stops formation of acylcarnitine
beta- hydroxy CoA DH inhibited by
NADH
Thiolase inhibited by
acetyl coa
lo energy charge creates ?
high isocitrate DH, low citrate … decrease fatty acid synthesis
High energy creates
low isocitrate DH, high citrate …. increased FA Synthesis
pathway by which cis containing double bonds enter b oxidation
Enoyl CoA Hydratase Beta-hydroxy FA CoA racemase Propionyl CoA CO2lase Methylmalonyl CoA racemase Methylmalonyl CoA mutase
in cis double bonds in beta oxi. Each double bond yields
1.5 fewer ATPs than corresponding saturated FA
peroxisomal beta oxidation is more __ than mito. beta oxidation
and
will not proceed beyond __?
specific
and
c8
MCAD Deficiency
Medium-chain acyl-CoA dehydrogenase
vomitting lethargy and coma
cause : hypoketotoic hypoglycemia , and dicarboxylic aciduria
hypoglycemia?
Fasting, decreased Gluconeogensis, increased glucose use
dicarboxylic aciduria
alter. ox FA
ketotoic ?
can’t degrade FA
MCAD is associated with
Reyes syndrome or infeant death syndrome
diabetic ketoacidosis causes ?
- incease glucagon/insulin ratio
- increase deg of FA
- increase acetyl coa
- increase ketonee bodies
- incerease ph
Abeta-lipoproteinemia….
Defective synthesis of B apoproteins…
Formation of chylomicrons & VLDLs are affected…
Can’t transport dietary lipid for storage
Chylomicrons, VLDLs, and LDLs are absent from plasma
neuropathy and red cell formation
during fasting/diabetes what happens to fat storage and LPL concentrations
they decrease
in the well fed state what happens to fat storage and LPL concentrations
they increase
in the well fed state insulin __ and fat storage __
inccrease , decrease
in the diabetes/fasting state insulin __ and fat storage __
decrease and increase
