TUMOR SHRINKING DIET
called oxidation, even when no oxygen atoms are involved. Py-
ruvic acid (pyruvate) is produced.
In this way the food has been prepared for the second part of
metabolism, called the Krebs cycle. Note that acetyl CoA is the
hub that links glycolysis to the Krebs cycle.
Now pyruvate (after turning into acetyl CoA) is joined by
oxaloacetate to make citric acid (the same as in lemon juice).
This gets oxidized to succinic acid, then to fumaric, then L-
malic (as in apple juice) and back to oxaloacetate. Throughout
the Krebs cycle oxygen is being used, electrons and hydrogen
are being freed, and carbon dioxide (CO 2 ) and ATP are being
Fig. 24 The Krebs cycle, the second part of food metabolism
C
C
C
acetyl CoA
citric
acid
Krebs
Cycle
oxalo
acetic
acid
pyruvic
acid
L-malic
acid
fumaric
acid
succinic
acid
CO 2
ATP
hydrogen
electrons