Bob's 5 Flashcards
What does pyruvate dehydrogenase do?
It converts pyruvate to acetyl coA. The enzyme is sensitive to vitamin B deficiency and is irreversible and so is a key regulatory step.
What happens with pyruvate dehydrogenase deficiency?
Lactic acidosis as that pathway is mobilised.
What does the Krebs or TCA cycle produce?
1 glucose= 2 cycles
2 GTP
6 NADH
2 CO2
2 FADH2
What biosynthetic precursors are produced in TCA cycle?
Fatty acids,amino acids, glucose,
Will TCA cycle work without oxygen?
No, the cycle itself doesn’t use oxygen but wont get ADP etc unless it is reoxidised in the electron transport chain.
How does stage 4 catabolism work?
Electrons from NADH and FAD2H are transferred to oxygen through a series of steps known as the electron transport chain and the free energy released is used to drive ATP synthesis through oxidative phosphorylation.
How does electron transport chain work?
Electrons used to drive H+ out through inner membrane and into intermembrane space creating a proton gradient. Electrons join with oxygen to form water and H+ passes down gradient (proton motive force pmf) and ATP synthase generates ATP.
What regulates oxidative phosphorylation?
High ATP levels mean low ADP and this means ATP synthase doesn’t have a substrate. H+ will build up in the intermembrane space and the process will cease.
How does cyanide and carbon monoxide poisoning work?
Cyanide prevents acceptance of electrons by O2 and carbon monoxide also interferes with oxidative phosphorylation.
What does uncoupling of oxidative phosphorylation involve?
Caused by some poisons it increase the permeability of the inner membrane resulting in the hydrogen gradient dissipating and no drive for ATP synthesis.
How does brown adipose tissue work?
Fatty acids used as uncouplers to allow extra heat generation. Fatty acids activate UCP1 which transports H+ back into mitochondria directly without using ATP synthase.
Oxidative phosphorylation vs substrate level phosphorylation
See grid in lecture
What is the net ATP production from glucose?
32 moles of ATP per mole of glucose
