Accessory pigment Accessory pigment Accessory pigments are light-absorbing compounds, found in photosynthetic organisms, that work in conjunction with chlorophyll "a". They include other forms of this pigment, such as chlorophyll "b" in green algal and higher plant antennae, while other algae may contain chlorophyll "c" or "d". In addition, there are many non-chlorophyll accessory pigments, such as carotenoids or phycobiliproteins, which also absorb light and transfer that light energy to photosystem chlorophyll. Some of these accessory pigments, in particular the carotenoids, also serve to absorb and dissipate excess light energy, or work as antioxidants. The large, physically associated group of chlorophylls and
Biological pigment general, contain six ubiquitous carotenoids: neoxanthin, violaxanthin, antheraxanthin, zeaxanthin, lutein and β-carotene. Lutein is a yellow pigment found in fruits and vegetables and is the most abundant carotenoid in plants. Lycopene is the red pigment responsible for the color of tomatoes. Other less common carotenoids in plants include lutein epoxide (in many woody species), lactucaxanthin (found in lettuce), and alpha carotene (found in carrots). In cyanobacteria, many other carotenoids exist such as canthaxanthin, myxoxanthophyll, synechoxanthin, and echinenone. Algal phototrophs such as dinoflagellates use peridinin as a light harvesting pigment. While carotenoids can be found complexed within chlorophyll-binding proteins such as