Energy Production Flashcards
Pyruvate dehydrogenase activated and inhibited by
Activated: pyruvate, coASH, NAD+, ADP, insulin
Inhibited: acetyl-CoA, NADH, ATP, citrate
Electron transport
Electrons on NADH and FAD2H transferred through a series
of carrier molecules to oxygen
Oxidative phosphorylation
Free energy released used to drive ATP synthesis
Proton motive force (pmf)
[H+] gradient (membrane potential) across inner mitochondrial
membrane
Do electrons in NADH or FADH2 have more energy? How many PTCs do they use?
NADH
NADH uses 3 and FADH2 uses 2
How many moles of ATP is produced from two moles of NADH and FADH2?
NADH synthesis of 5 moles of ATP (P/O = 2.5)
FADH2 synthesis of 3 moles of ATP (P/O = 1.5)
How does cyanide inhibit the electron transport chain?
Prevents acceptance of electrons by O2
Inhibitors of the electron transport chain
Cyanide and carbon monoxide
Block flow of electrons, no pmf
Uncouplers
Dinitrophenol, dinitrocresol, fatty acids
Increase permeability of membrane to H+
H+ enters mitochondria without driving ATP synthetase
Dissipates p.m.f.
Ox/Phos diseases
Genetic defects in proteins encoded by mtDNA
Decrease in electron transport and ATP synthesis
Extra heat generation in brown adipose tissue
Thermogenin (UCP1)
In response to noradrenaline, lipase releases fatty acids from triacylglycerol. Oxidised fatty acids activate UCP1. Electron Transport uncoupled from ATP Synthesis. Energy of p.m.f. is then released as extra heat.
Which vitamins cannot be synthesised in the body?
A D E K
What is triacylglycerol made from?
Glycerol and fatty acids
What do chylomicrons contain?
Fatty acids
Hormone sensitive lipase in lipid metabolism stimulated and inhibited by…
Stimulated by glucagon and adrenaline
Inhibited by insulin