What is citrate from the TCA cycle used for?
fatty acid and sterol synthesis
what is alpha ketogluterate from the TCA cycle used for?
amino acid synthesis (neurotransmitters)
what is succinyl CoA from the TCA cycle used for?
what is malate from the TCA cycle used for?
what is oxaloacetate from the TCA cycle used for?
amino acid synthesis
what happens to the TCA cycle when intermediates are removed?
slows down because there is no oxaloacetate
What is an anapleurotic reaction?
reaction that returns intermediates to the TCA cycle
what is the most important anapleurotic reaction?
pyruvate carboxylase- conversion of pyruvate to oxaloacetate when Acetyl-CoA accumulates (means there is no oxaloacetate to react with Acetyl-CoA--> triggers conversion of pyruvate to oxaloacetate)
what is the role of pyruvate dehydroxylase?
convert pyruvate to oxaloacetate when acetyl-CoA builds up
where is pyruvate carboxylase activity highest?
liver and neuron mitochondria
what are the steps of pyruvate carboxylase reaction?
ATP + HCO3- + pyruvate (pyruvate carboxylase)--> oxaloacetate
pyruvate has 3 carbons, oxaloacetate has 4
extra carbon comes from HCO3-
what is the key regulated step of the TCA cylce?
how is the isocitrate dehydrogenase reaction regulated?
activated by ADPregulated by ATP/ADP ratio
inhibited by ATP
what happens when the TCA cycle is inhibited at the key regulatory step?
citrate leaves the TCA cycle for other uses
what does loss of citrate require for the TCA cycle to continue?
anapleurotic reaction to replenish citrate to replenish oxaloacetate (pyruvate carboxylase reaction)