Photosynthetic pigment
A
photosynthetic pigment is a pigment present in
chloroplasts or photosynthetic
bacteria which provides the energy necessary for
photosynthesis.
Green plants have five closely-related photosynthetic pigments:
Chlorophyll a is the most common of the five, present in every plant that performs photosynthesis. The reason that there are so many pigments is that each absorbs
light more efficiently in a different part of the
spectrum. Chlorophyll a absorbs well at a
wavelength of about 400-450 nm and at 650-700 nm; chlorophyll b at 450-500 nm. Xanthophyll absorbs well at 400-530 nm. However, none of the pigments absorbs well in the green-yellow region, which is responsible for the abundant green we see in nature.
Pigmentation varies among the different groups of algae. Of particular note are the kinds of chlorophylls present.