carbohydrates 4 Flashcards
What reaction does pyruvate dehydrogenase catalyse? Where does this reaction occur?
pyruvate + CoA + nad —> acetyl CoA + CO2 + NADH + H
mitochondrial matrix
What does pyruvate dehydrogenase require?
cofactors derived form vitamin B
Where does the tricarboxylic acid cycle occur?
mitochondrial matrix
What does a pyruvate dehydrogenase deficiency result in?
lactic acidosis
What are the products of 1 krebs cycles?
6 NADH 2 FADH ATP/GTP 2 co2 intermediates of metabolism- HUB for metabolites
What does acetyl CoA react with to produce citrate a C6 molecule?
oxaloacetate C4
What are the main regulatory steps in the krebs cycle and what regulates them?
isocitrate + nad–>alpha ketoglutarate+ nadh by isocitrate dehydrogenase
alpha ketoglutarate + nad + coA–> succinyl coA + co2 + NADH by alpha ketoglutarate dehydrogenase
high and low energy signals
What are the key processes in oxidative phosphorylation?
electron transport and oxidative phosphorylation
Explain the electron transport chain
electron transferred to oxygen via complexes to produce water
energy lost used to translocate H to produce proton motive force
Explain how electron transport chain and oxidative phosphorylation are coupled
proton motive force generated by ETC
H return across membrane through complex V the ATP synthase driving the generation of ATP
How is oxidative phosphorylation regulated?
mitochondrial ATP concentration
How does cyanide stope ETC?
stop electron transfer to oxygen
What do uncouplers do? Give two examples.
increase permeability of membrane to H
dissipates pmf therefore no ATP synthesis so ADP remains high and ETC continues
FA’s and dinitrophenol
What is the role of uncouplers in brown adipose tissue?
degree of uncoupling controlled to allow extra heat generation
Explain the process of uncoupling in brown adipose tissue
cold
noradrenaline
lipases activated
fa’s produced
FA oxidation —> NADH/FADH2–> electron tranpsort
FA activate therogenin (UCP1) -> uncoupler remove pmf
energy used for heat generation instead
