metabolism Flashcards
(35 cards)
gluconeogenesis what can be used
gluconeogenic amino acids, pyruvate, glycerol, lactate
gluconeogenesis where it occurs
only liver and kidneys
begins in mitochondria w oxaloactetate
amino acid (ketogenic)
turned into AcCoA
amino acid (glucogenic)
form glucose or enter the TCA cycle
how is nitrogen removed
converted to ammonia
buildup of ammonia is toxic -> has to be excreted
urea cycle occurs in liver
cytosol and mitochondria
2 nitrogen groups + CO2 -> urea and water
urea excreted in the urine
FA beta oxidation where does it occur
mitochondria
FA beta oxidation role of carnitine
shuttle FA into the mitochondria
FA beta ox metabolic products
2 C cleaved from FA chain -> Acetyl-CoA
NADH, H, FADH2
amino acid metabolism where
liver
amino acid metabolism requires what
deamination
AA can enter as
pyruvate, acetyl coa, tca cycle
carb’s role in beta ox
TCA needs oxaloacetate
cells can synthesize from pyruvate
carbs needed to create pyruvate
carb intake low
low oxaloacetate = low citric acid cycle
build up of acetyl coa
diverted into ketone production in liver
cells can use ketones (ketone -> acetyl coa-> TCA)
what gluconeogenesis requires
atp, biotin, riboflavin, niacin, b6
gluconeogenesis anabolic or catabolic
anabolic
low levels of insulin promote
gluconeogenesis, protein breakdown, lipolysis
increased insulin promotes
glycogen, fat, protein synthesis
feasting
- metabolism favors fat formation
FA -> triglycerides
glucose -> glycogen or AceCoA -> FA
AA -> Acetyl CoA -> FA
hormones in initial fasting
Hormone sensitive lipase
triglycerides -> glycerol backbone + FA
increased by glucagon, growth hormone, and epu
decreased by insulin
short term fasting
- reliance on AA for glucose via gluconeogenesis
2. increased ketone formation
3. increased utilization of FA for energy
prolonged fasting
- increased formation of ketones
- body tissue broken down to make glucose form gllucogenic amino acids
adaptations to survive fasting
- slow metabolic rate (reduce energy req, slow breakdown of lean body tissue for glucoeneogenesis)
- allow nervous system to use more ketone bodies
ketosis in semistarvation/fasting
- glucose and insulin levels fall
- FA flow into bloodstream and form ketone bodies in liver
- SPARE PROTEINS from being used
- heart, muscle, kidneys, and eventually the brain can use these for fuels
glycolysis where
cytosol