Photosynthetic pigment

A Photosynthetic pigment is a pigment present in chloroplasts which provides the energy necessary for photosynthesis.

In green plants, there are five closely-related photosynthetic pigments:

• Chlorophyll-a - a is blue-green pigment
• Chlorophyll-b - a yellow-green pigment
• Carotene' - carotene is an orange pigment
• Xanthophyll - is a yellow pigment
• Phaeophytin - phaephytin? is a grey pigment

Chlorophyll-a is the most common of the five, present in every plant which performs photosynthesis. The reason that there are so many is that each absorbs light more efficiently in a different part of the spectrum. Chlorophyll a absorbs well at a wavelength of about 400-450nm and again at 650-700nm. Chlorophyll b at 450-500nm. Xanthophyll? absorbs well 400-530nm. However none of the pigments absorb well in the green-yellow wavelengths and this 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, which may be either a and b as in the Prochlorophyta?, green plants and euglenids, a and c as in the stramenopiles, dinoflagellates, and other forms, or simply a by itself, as in the cyanobacteria? and Rhodophyta?.