7: Acetyl-CoA and the TCA Cycle Flashcards
Glycolysis summary
glucose to acetyl CoA
TCA cycle summary
Acetyl CoA is oxidized to CO2 and electron carries NAD+ and FAD are reduced
OXPHOS summary
electrons from fuel molecules are transferred to O2 and ATP is produced
What enzymes catalyze redox reactions?
dehydrogenases
What vitamin are NAD and NADP derived from?
Niacin (B3)
What disease does a nutrition niacin deficiency cause in humans?
pellagra
What disease does a nutrition niacin deficiency cause in dogs?
black tongue
Where does glycolysis occur?
cytoplasm
Where does the TCA cycle occur?
mitochondria
3 metabolic destinations of pyruvate
- acetyl CoA
- lactate
- alanine
3 possible fates of acetyl CoA
- TCA cycle
- ketone bodies
- sterols and fatty acids
pyruvate dehydrogenase (PDH) complex structure
3 enzymes and many coenzymes
What does a thiamine (B1) deficiency cause?
inability to oxidize pyruvate causing weakness and trouble walking
Regulation of PDH
- feedback inhibition
- enzymatic regulation (PDH kinase or phosphatase)
What does pyruvate dehydrogenase covert?
pyruvate to acetyl CoA
Is the phosphorylated for of PDH active or inactive?
inactive
PHD kinase effect on PHD
inhibits
Phosphatase effect on PHD
restores activity
Which molecules increase the activity of the kinase that phosphorylates PDH?
NADH and acetyl CoA
Which molecules decrease the activity of the kinase that phosphorylates PDH?
CoASH, NAD+, ADP, pyruvate
Which molecules increase the activity of the enzyme that DEphosphorylates PDH?
Mg2+ and Ca2+
What dog breeds is exercise-induced collapse common in?
Clumber and Sussex Spaniels
What causes exercise-induced collapse?
PDH phosphatase 1 deficiency
What does Acetyl CoA combine with?
oxaloacetate
