Chlorophyll is a green pigment consists of tetrapyrrole ring
with a central magnesium ion. It has a long hydrophobic
phytol chain in its structure. It is found in some varieties in
plants and algae (Aminot, 2000). Two types of chlorophyll,
a and b are present in green algae and terrestrial plants. The
difference between these two chlorophylls is a methyl
moiety in chlorophyll a replaced by a formyl group in
chlorophyll b. The ratio of chlorophyll a to chlorophyll b in
higher plants is approximately 3:1. Chlorophyll absorbs light
mainly in the red (650 – 700 nm) and the blue - violet (400 –
500 nm) regions of the visible spectrum. Green light (~550
nm) is not absorbed but reflected giving chlorophyll its
characteristic color. Chlorophyll a possesses a green-blue
color, and chlorophyll b possesses a green-yellow color
(Arnon, 1849).