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
Photosynthesis light, oxidize cytochrome f, chlorophyll a (and other pigments) will absorb another light, but will reduce this same oxidized cytochrome, stating the two light reactions are in series. In 1893, Charles Reid Barnes proposed two terms, "photosyntax" and "photosynthesis", for the biological process of "synthesis of complex carbon compounds out of carbonic acid, in the presence of chlorophyll, under the influence of light". Over time, the term "photosynthesis" came into common usage as the term of choice. Later discovery of anoxygenic photosynthetic bacteria and photophosphorylation necessitated redefinition of the term. After WWII at late 1940 at the University of California,