Chlorophyll of plants
On a dry weight basis chloroplasts contain the following
Protein 40-50%
Chlorophyll 7-10%
RNA 2-5%
DNA 1% or less
Phospholipid 23-25%
Carotenoids 1-2%
Enzymes or Coenzymes Some
Atoms of Fe, Cu, Zn, Mn and Mg Some
Chlorophyll molecule has a complex hydrophilic head made of four pyrrole rings bound to each other
and forming a porphyrin ring to which is attached a long hydrophobic phytol (C28H39) chain (tail). The
porphyrin ring is composed principally of four pyrrole nuclei linked together bearing side chains. The
metal constituent of the molecule, the magnesium, is incorporated in this ring (Fig. 31.39). The
hydrocarbon phytol group on hydrolysis gives rise to the alcohol phytol which is an isoprenoid
derivative.
