Metabolism 3 Flashcards
transport of acyl-coA into mitochondrial matrix: what cycle?
acyl coA + carnitine via CAT1 = acyl carnitine. translocase swaps acyl carnitine for a carnitine (antiport). CAT II converts acyl carnitine into carnitine.
what determines rate of transport of acyl coA into mito. matrix?
indirectly determined by CAT 1 - and thus CAT 1 determines rate of Box
Boxidation: definition?
cyclical process via which fatty acids are broken down, two carbon atoms at a time to produce acetyl coA (plus lots of ATP)
oxidation of fatty acids occurs under ___ conditions only
aerobic
what happens to acetyl coA in muscle
catabolized via CAC and OXP PHOS to make lots of ATP
what happens to acetyl coA in liver
converted to a special type of fuel molecule for export in blood stream: ketone bodies
acetyl co A cannot be used to make?
glucose
ketone bodies: definition and properties
metabolic fuel molecules: small, water soluble + easily transported in the blood (vs. FAs which are hard to transport)
ketone bodies: made how?
two acetyl coA combined together
some problems with ketone bodies
acidic = metabolic problems. acetone is also not good for you; side product of ketone body production when it happens a lot
fatty acid synthesis: occurs mainly where? enables?
mainly in the liver. enables storage of excess acetyl coA (excess glucose; amino acids)
first step of FAS?
acetyl coA must be transported OUT of the mitochondrial matrix (since that’s where it is always made)
FAS: all carbon atoms come from? process involves?
acetyl coA: sequential addition of two carbon atoms from acetyl co A to the growing acyl chain
FAS: rate limiting step?
formation of new carbon carbon bond which requires energy, catalyzed by acetyl co A carboxylase (ACC)
FAS ends with the production of?
palmitate (16:0)
regulation of triacyglycerols: breakdown and synthesis? (also include location)
lipolysis (adipose tissue) determined by activity of hormone sensitive lipase. fat synthesis (adipocytes and liver) only limited by supply.
regulation of fatty acids: synthesis and breakdown? (also include location)
FAS (liver) determined by ACC activity. Box (liver and muscle) determined by regulating transport of FAs into mitochondrial matrix via CAT 1
hormone sensitive lipase: effects of insulin and glucagon?
insulin (promotes storage/use) inhibits HSL. glucagon activates HSL (promotes breakdown)
rate of B-ox is ____ but there are no? instead, tightly controlled by what 3 things?
highly variable but no rate limiting enzymes. tightly controlled by ADP local concentration, enzyme induction, inhibition of fatty acid transport
ADP effect on Box
higher ADP = increases beta oxidation (less ATP = more ADP so you want more breakdown)
inhibition of fatty acid transport and B-ox?
reciprocal regulation of B-ox and FAS. 1st intermediated of FAS, malonyl coA, inhibits CAT 1 so inhibits transport to where B-ox would take place)
