jenny beta oxidation of FA Flashcards
no C-C double bonds
saturated FA
at least one CC double bond
unsaturated FA
one CC double bond
monosaturated
two or more CC double
polyunsaturated
2-3 carbons
short chain
4-12 carbons
medium chain
12-20 carbons
long chain
more than 20
very long chain
fatty acids are stored as neutral lipids called____
triaclyglycerols (TGs)
what lipases chop off the fatty acids?
triacylglycerol lipases
diacylglycerol and monoacylglyerol lipases
are free fatty acids in cytoplasm?
rare, they are bound to glycerol, coenzymeA, or carnitine
in blood where FA is found?
Lipoproteins
Blood that circulate, FA is bound to what?
serum albumin
this is major serum protein
albumin
60% of total plasma protein
where beta-oxidation occur?
mitochondrial matrix (longer chain)
where unsaturated FA begin beta-oxidation?
in peroxisome
long chain FA converted to what for transport across inner membrane
acylcarnitine
how long chain FA is transported thru membrane?
carnitine:acylcarnitine translocase (CAT)
What is key regulatory step in beta oxidation?
FA –> acylcarnitine
transport across inner membrane by CAT
carrier for FA breakdown
acylgroup-s-coa
carrier for FA biosynthesis
acyl group- S- ACP
cofactor FA breakdown
NAD+/NADH
cofactor- FA synthesis
NADP+/NADPH
B-oxdiation degrades__ at a time
2 Carbon
______condenses fatty acid with coa, with simultaneous hydrolysis of ATP to AMP+PP
ACyl-Coa synthetase
what reaction moving the oxidation process forward?
hydrolysis of pp.
four key repeated reaction for b-oxdiation
oxdiation, hydration, oxidation, thiolysis
net yield of ATP per palmitate ?
106 atp
how many ATP expended to activate palmitate?
2
acetyl coa from FA oxidation (2Carbon) are lost as ___ in ____cycle
CO2 , TCA cycle
you must maintain blood glucose level
reducing power for beta-oxidation?
NADH
~50% FA in diet are unsaturated-double bonds must be?
isomerized and reduced
odd-chain FA - 3C propionyl Coa. what happen in b-oxidation?
carboxylated to 4C methylmalonyl coa
then –> succinyl coa –> TCA cycle
what happens to medium chain FA?
used up immediately
carnitine ___only FA from perioxisome
exports ( not involved in import)
where detoxification of FA- like compounds- produces dicarboxylic acid can be excreted. what kind of oxidation and where this occurs?
w-oxidation in ER microsome
a-oxidation occurs where?
peroxisomes with some branched FA
must remove first carbon
what disease is related to a-oxidation?
refsum disease - genetic defect in a-oxidation –> ataxia, neuropathy
patient deficient in this transporter have hypoglycemia
carnitine
treat with carnitine supplement
what is the first step of b-oxidation?
acyl coa DH
deficiency in acyl coa Dehydrogenase
dicarboxylic aciduria (build up from TCA )
defects in ___ one of the most common inborn error
MCAD
medium chain acyl coa dehydrogenase
where and what is used to make ketone body
acetyl coa in LIVER
where KB is converted back to acetyl coa -> TCA
Skeletal muscle/tissues
what are the preferred/normal energy source for kidney cortex cells and cardiac muscle?
acetoacetate and beta-hydroxybutyrate
where KB synthesis occur?
only in mitochondria matrix
can ketone body transport in blood without albumin/other binding protein?
Yes. easily.
acetoacetyl coa –> HMG-Coa
HMG-CoA synthase
limiting step for KB synthesis
HMG-CoA synthase
how KB can be converted to TCA cycle?
aceoacetate –> acetoacetyl coa
by b-ketoacylcoa transferase
what are interchangable for KB
Acetoacetate and b-hydroxybutyrate
in normal, 1:1
DM patient with KB this leads to?
excess of acetyl Coa
excess KB
Hyperglycemia -> dehydration -> reduce excretion of KB -> ketoacidosis
which tissue/cell use KB as main energy source?
intestinal mucosa cells
adopocytes
brain under prolonged starvation
90mg/100ml =
5mM
60mg/100ml=
3.3mM
glucose < __mM leads to coma, death
2.2mM
