Chlorophyll ''d'' (Chl ''d'') is a form of

chlorophyll Chlorophyll is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words (, "pale green") and (, "leaf"). Chlorophyll allows plants to absorb energy ...

, identified by Harold Strain and Winston Manning in 1943. It was unambiguously identified in '' Acaryochloris marina'' in the 1990s. It is present in

cyanobacteria Cyanobacteria ( ) are a group of autotrophic gram-negative bacteria that can obtain biological energy via oxygenic photosynthesis. The name "cyanobacteria" () refers to their bluish green (cyan) color, which forms the basis of cyanobacteri ...

which use energy captured from sunlight for photosynthesis. Chl ''d'' absorbs

far-red Far-red light is a range of light at the extreme red end of the visible spectrum, just before infrared light. Usually regarded as the region between 700 and 750 nm wavelength, it is dimly visible to human eyes. It is largely reflected or transmit ...

light, at 710 nm wavelength, just outside the optical range. An organism that contains Chl ''d'' is adapted to an environment such as moderately deep water, where it can use far red light for photosynthesis, although there is not a lot of visible light. Chl ''d'' is produced from chlorophyllide ''d'' by chlorophyll synthase. Chlorophyllide ''d'' is made from chlorophyllide ''a'', but the oxygen-using enzyme that performs this conversion remains unknown as of 2022.

References

{{Plant pigments Tetrapyrroles Photosynthetic pigments