fat metabolism Flashcards
basic structure of triglyceride
glycerol - 3FA
main TG sources
- adipose tissue
- skeletal muscle
mobilization
TG gets broken down into 3FA and glyercol through hormone sensitive lipase
- glycerol goes to the liver to be converted to glucose
-the 3 FAs go to the muscle to be catabolized for energy
activators of HSL
norepinephrine
epinephrine
inhibitors of HSL
insulin
how does the regulation work ?
β-adrenergic
receptor stimulation
activates cAMP
signaling cascade to
phosphorylate HSL,
increase its activity,
& activate lipolysis-insulin signaling
degrades cAMP to
reduce this signal
and inhibit lipolysis
why is HSL complex
HSL is considered rate-limiting for lipolysis
but need all 3 lipases to hydrolyze a TG
transport
FA circulates in the blood via albumin
- 4 FFA on one albumin
Uptake
3 different transporters:
1.FAT/CD36 (most important( glut 4)
(GLUT 1)
2.FATP
3.FABPpm
Palmitate uptake into
muscle
demonstrates
characteristics of a
saturable protein
mediated transport
system (i.e., near-
equilibrium enzyme
kinetics)
activation
FA prepared for breakdown
-FA enter the cytosol w/ a transporter
-CoA attaches to the FA this cost 2 ATP
-F acyl- CoA in the cystol is on the transporter FABPc
carnitine
acts as the transporter
located in intramitospace
what is on the outer-mitochondria space
carnitine palmitoyl
transferase (CPT)
what enters the mito matrix
Fatty acyl-Coa
When would H+ be produced?
pyruvate being converted into lactate produces H +
resulting in inhibition of CPT1
