Integrated Metabolism Flashcards
where is the majority of our energy reserve?
adipose - TAG 83%
what two ways can adipocytes metabolically turnover TAGS?
mobilization = lipolysis (HS Lipase) Synthesis = lipgenesis (LPL)
what are the precursor molecules needed for the synthesis of TAG?
glycerol 3-P
fatty acids
in what state does the synthesis of TAGs occur?
well fed state
what does leptin induce the expression of and activate of?
UCP 2
AMPK
what is obestiy linked with?
insulin resistance
what is adipose tissue regulated by?
nutritional
metabolic and
hormonal factors
what is lipolysis?
TAGs are hydrolyzed - broken down
what is esterification?
TAGs are formed - the process
what are the precursor molecules for the synthesis of TAGs?
glycerol 3 P
FA
what has all the enzymes for FA synthesis? what is ironic about this
adipocytes
they only contribute to a minor amount of FA de novo synthesis in humans!
what enzymes do adipocytes not have?
glycerol kinase
what is the purpose of glycerol kinase?
Adipocytes lack glycerol kinase so they cannot metabolize the glycerol produced during triacyl glycerol degradation.
This glycerol is instead shuttled to the liver via the blood where it is:
phosphorylated by glycerol kinase to glycerol phosphate
converted to DHAP (dihydroxyacetone phosphate) which can participate in glycolysis or gluconeogenesis.
what does insulin ruling stimulate the increasing numbers of what receptors?
GLUT 4 - its insulin dependent
where do glycerol and CM remnants go to?
the liver
abdominal white adipose tissue is very responsive to what which leads to what?
epinephrine
leads to release of FA - which extra FA goes to liver and increases VLDL
what is thermogenin UCP -1?
mitochondrial OXPHOS uncoupler
what is absence of adipose tissue associated with?
severe insulin resistance
loss of hormonal signals from adipose
dysreg. of TAG and FA levels
what gene is associatedf with leptin and where are its receptors?
ob gene
hypothalamus
what does leptin induce expression of ?
UCP-2
what does leptin do?
supress appetite
activates AMPK
what is AMPK?
regulated fuel metabolism by phosphorylation - so everything that takes place at low insulin/glucagon ratio!
- increase catabolic (building ) - increased beta ox
- turn off anabolic (breakdown) - no glycogen, TAG or FA/cholsterol sun, decrease protein synthesis
what is obesity linked to?
insulin resistance - hyperinsulinemia
what does insulin ruling stimulate the increasing numbers of what receptors?
GLUT 4 - its insulin dependent
