Chlorophyll is a green photosynthetic molecule. Chloroplasts are abundant in leaf mesophyll tissue. Green plants have five types of chlorophyll. Chlorophyll a, b, c, d and e. Chlorophyll-a is yellowish-green and chlorophyll-b is bluish-green. Some chlorophyll-a (P-700) absorb light at a wavelength of 700 nm, while some chlorophyll-a (P-680) absorb light at a wavelength of 680 nm. These chlorophylls participate in photosynthesis. Photoreactions occur in quantosomes of thylakoids and photoneutral reactions occur in the stroma. Modern scientists believe that light energy absorbed by chlorophyll-a is used in photosynthesis. Light energy absorbed by other pigments is passed on to chlorophyll-a. Some green sulfur bacteria like Rhodopseudomonas, Rhodospirillum, Chlorobium etc. contain bacteriochlorophyll. The chemical constituents of chlorophyll are carbon, hydrogen, oxygen, nitrogen and magnesium.
Chlorophyll-a : C55H72O5N4Mg
Chlorophyll-b : C55H70O6N4Mg
Chlorophyll-c : C35H30O5N4Mg
Chlorophyll-d : C54H70O6N4Mg