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What
is Gluconeogenesis?
•Gluconeogenesis
is the formation of glucose from non-carbohydrate precursors, such as pyruvate, lactate, certain amino acids, and
intermediates of TCA cycle.
•Glyoxylate
cycle is special example of gluconeogenesis that is specific to plants. It represents a shortcut, or shunt,
across the TCA cycle. The following reactions summarize the chemistry of the glyoxylate
cycle:
•a.
isocitrate ---> succinate + glyoxylate
•b.
glyoxylate + Ac-CoA ---> malate --> oxaloacetate
•c.
oxaloacetate is exported from glyoxysome ---> to mitochondrion ---> gluconeogenesis