Starting from the Oxaloacetate (OAA) (C4)
combined with Acetyl coA (C2) was born as citric acid
(C6) and citric acid to change through.
Decarboxylation is C5 instead
(Alpha-ketoglutarate) before the Decarboxylation again until becomes a C4
.It is Oxaloacetate of back again.