#Id: 8838
#Unit 6. System Physiology – Plant
The biosynthesis of chlorophylls and heme begins with the synthesis of δ‐aminolevulinic acid (ALA) from glutamic acid.
Two molecules of ALA react to yield porphobilinogen (PBG).
Four molecules of PBG form the ring structure of protoporphyrin IX, the common branch point for the synthesis of heme and chlorophyll.
To make chlorophyll, a magnesium chelatase inserts Mg into the protoporphyrin IX ring