Chlorophyll ''c'' refers to forms 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 ...
found in certain marine algae, including the photosynthetic
Chromista
Chromista is a proposed but polyphyletic obsolete Biology, biological Kingdom (biology), kingdom, refined from the Chromalveolata, consisting of single-celled and multicellular eukaryotic species that share similar features in their Photosynthesi ...
(e.g.
diatoms and
brown algae
Brown algae (: alga) are a large group of multicellular algae comprising the class (biology), class Phaeophyceae. They include many seaweeds located in colder waters of the Northern Hemisphere. Brown algae are the major seaweeds of the temperate ...
) and
dinoflagellates.
These pigments are characterized by their unusual chemical structure, with a
porphyrin as opposed to the
chlorin
In organic chemistry, chlorins are tetrapyrrole pigments that are partially hydrogenation, hydrogenated porphyrins. The parent chlorin is an unstable compound which undergoes air oxidation to porphine. The name chlorin derives from chlorophyll. ...
(which has a reduced ring D) as the core; they also do not have an isoprenoid tail. Both these features stand out from the other chlorophylls commonly found in algae and plants.
It has a blue-green color and is an
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 vascular ("higher") plan ...
, particularly significant in its absorption of light in the 447–520 nm wavelength region.
Like
chlorophyll ''a'' and
chlorophyll ''b'', it helps the organism gather light and passes a quanta of excitation energy through the light harvesting antennae to the
photosynthetic reaction centre.
[
Chlorophyll ''c'' can be further divided into chlorophyll ''c''1, chlorophyll ''c''2,]
Chlorophyll ''c''1
Chlorophyll ''c''1 is a common form of chlorophyll ''c''. It differs from chlorophyll ''c''2 in its C8 group, having an ethyl group instead of vinyl group (C-C single bond instead of C=C double bond).
Its absorption maxima are around 444, 577, 626 nm and 447, 579, 629 nm in diethyl ether
Diethyl ether, or simply ether, is an organic compound with the chemical formula , sometimes abbreviated as . It is a colourless, highly Volatility (chemistry), volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It belongs ...
and acetone
Acetone (2-propanone or dimethyl ketone) is an organic compound with the chemical formula, formula . It is the simplest and smallest ketone (). It is a colorless, highly Volatile organic compound, volatile, and flammable liquid with a charact ...
respectively.
Chlorophyll ''c''2
Chlorophyll ''c''2 is the most common form of chlorophyll ''c''.
Chlorophyll ''c''3
Chlorophyll ''c''3 is a form of chlorophyll ''c'' found in microalga ''Emiliania huxleyi
''Gephyrocapsa huxleyi'', also called ''Emiliania huxleyi'', is the most abundant species of coccolithophore in modern oceans found in almost all ecosystems from the equator to sub-polar regions, and from nutrient rich upwelling zones to nutr ...
'', identified in 1989.[
]
Biosynthesis
Chlorophyll ''c'' synthesis branches off early from the typical Chlorophyllide synthesis pathway, after divinylprotochlorophyllide (DV-PChlide) is formed. It has been established that DV-PChlide and MV-PChlide are processed directly by a 171 oxidase (CHLC, chlorophyll ''c'' synthase) into Chl ''c''2 and Chl ''c''1, respectively.
Structure
References
{{Plant pigments
Porphyrins
Photosynthetic pigments
Brown algae
Diatom biology