Chapter 12 (TCA cycle)
1) Know the overall reaction of the citric acid cycle
2) Know the names of the intermediates of the TCA cycle from pyruvate to OAA.
Know the name of the enzymes involved in each step. Know the co-factors
involved in each step of the TCA cycle. Be able to recognize the structures of
each intermediate of the TCA cycle (you will not be required to draw them on the
exam).
3) Know what co-factors are required by pyruvate dehydrogenase and beable to
describe what their function is in the conversion of pyruvate to acetyl-CoA.
4) Know which steps are energy producing (generate GTP and NADH).
5) Know which steps of the TCA cycle are involved in oxidative-decarboxylation,
substrate level phosphorylation, and oxidation.
6) Know which steps of the TCA cycle are regulated (pyruvate dehydrogenase,
isocitrate dehydrogenase, -ketoglutarate dehydrogenase). Know all allosteric
inhibitors and activators for each step. I did not talk much about Ca2+ as an
activator, but you need to know that it is an activator of isocitrate dehydrogenase
and -ketoglutarate dehydrogenase.
7) Know how pyruvate dehydrogenase and isocitrate dehydrogenase are regulated by
phosphorylation.
8) Know that intermediates of the TCA cycle can provide precursors for the
biosynthesis of fatty acids, isoprenoids, amino acids, carbohydrates, purine and
pyrimidine nucleotides. Acetyl-CoA -> fatty acids/isoprenoids. -ketoglutarate ->
amino acids/purine nucleotides. Fumarate -> amino acids/pyrimidine nucleotides.
Oxaloacteate -> amino acids, carbohydrates, pyrimidine nucleotides. Know these
and if given a diagram of the TCA cycle be able to show which intermediate can
be directed towards the synthesis of what biomolecules.
9) Know that anaplerotic rxns are required to replace intermediates of the TCA cycle
that were siphoned off by biosynthetic pathways. Know the three anaplerotic
reactions discussed in class. PEP -> oxaloacetate (PEP carboxylase). Pyruvate ->
oxaloacetate (Pyrvuate carboxykinase). Pyruvate -> Malate -> oxaloacetate
(malate enzyme). If given a diagram of the TCA cycle be able to show where each
enzyme feeds into the TCA cycle. Show all co-factors involved in each reaction.