🚀 go-pugleaf

In article <1993Jan8.174736.11471@leland.Stanford.EDU>,
kksng@leland.Stanford.EDU (Kenneth Kai-Sing Ng) writes:
|>
|>A second role of the TCA cycle is to generate, again from
|>acetyl-CoA, four carbon building blocks for the synthesis of amino acids and
|>glucose.

Some microorganisms (particularly the cyanobacteria) are capable of running
the TCA cycle backwards to generate pyruvate (and hence eventually glucose)
from acetyl-CoA.  This doesn't happen in most organisms, though.  Man and I
think all other mammals are incapable of net new glucose formation from
acetyl-CoA.  The seeds of plants, which are very active in such synthesis,
don't do so using the TCA cycle.  They use a shunt called the glyoxylate
cycle.  Most organisms lack two key enzymes necessary to run the glyoxylate
pathway and thus generate new glucose from acetate.

--PSW