10/7 Energy From Fat Flashcards
what tissues can utilize FA
liver, heart, mm
what tissues can utilize ketones
brain, heart, muscles
which two enzymes liberate FAs in adipocytes, and (+) (-)
adipose TG lipase
hormone-sensitive lipase
(+) glucagon, (nor)epinepherine
(-) insulin
how do FAs travel in the blood
free or bound to albumin
what enzymes removes CoA and adds carnitine
carnitine palmitoyl transferase 1 (occurs in intermembrane space)
rate-limiting step
(-) malonyl-CoA (high in fed state)
how does carnitine-FA get into the mitochondrial matrix?
translocase
how is carnitine-FA reactivated in the matrix
carnitine palmitoyl transferase 2 (CPT2) swaps the carnitine for CoA
characteristics of fasting and stress
decrease in insulin, increase in glucagon
increase in FA mobilization [adipocytes]
FAs–> Acetyl-CoA [oxidation]
Acetyl-CoA –> ketones [liver]
MCAD deficiency
w/o b-oxidation, can’t make glucose or ketons b/c FAs provide the acetyl-CoA the liver needs for ketone synthesis and glyconeogenesis
treatment: no fasting, smaller/frequent/low fat meals
MCAD deficiency labs
low glucose low pH high ammonia high creatine kinase high lactate/pyruvate
Refsum disease
defective perioxisomal a-oxidation (or transporter defect)
pytanic acid deposited in nerve tissue
retinitis pigmentosa, blindness, anosmia, bony defects, muscle wasting, scaly skin
what is the product of odd-chain FA oxidation
propionyl CoA
what is propionyl CoA typically metabolized to?
succinyl CoA
what vitamins are needed for odd-chain FA oxidation
B7 (biotin)
B12 (cobalamin)
B12 deficiency
megaloblastic anemia w/ hypersegmented neutrophils, peripheral neuropathy, increased blood methylmalonic acid, increased homocysteine
