What Are The Different Types Of Pigments In Cyanobacteria?
If you’ve ever taken an introductory biology class, you may be familiar with the term cyanobacteria. Cyanobacteria are photosynthetic bacteria that produce their food through the process of photosynthesis and use pigment molecules such as the carotenoid chlorophyll-a to create energy from light to do so. However, there are several different pigments, or types of pigment molecules, that cyanobacteria can use to create energy in addition to chlorophyll-a and chlorophyll-b such as phycocyanin and fucoxanthin.
Pigment Green 7 – Chlorophyll.
We’ve mentioned chlorophyll before as a pigment that gives plants their green colour. But what other pigments are found in chlorophyll? Scientists have discovered that many species of bacteria contain a pigment called Pigment Green 7, or Chlorophyll. The presence of Chlorophyll has been used to identify and classify cyanobacteria species. This pigment is notable because it absorbs light at a wavelength similar to those emitted by far-red radiation, which allows organisms containing it to photosynthesize at wavelengths longer than 700 nm. (source) Other organisms containing Chlorophyll can absorb far-red radiation but not near-infrared light.
Thus, scientists have long wondered how organisms using only chlorophyll could also absorb near-infrared rays. These organisms use an additional pigment called phycobiliproteins, a class of proteins that capture visible light and transfer it to chlorophyll for use in photosynthesis. Cyanobacteria with Phycobiliproteins absorb red sunlight more efficiently than any other group of plants on Earth. They were instrumental in converting our planet from an atmosphere with little oxygen into one rich in O2!
Peridinin – Chlorophyll.
Chlorophyll is a green pigment that plays an important role in energy capture during photosynthesis. In ocean water, chlorophyll absorbs blue light (400 – 500 nm) and reflects red light (600 – 700 nm). This is why we see sea plants as bright green. Chlorophyll b has a longer wavelength than does chlorophyll a, which allows it to absorb more light in certain conditions but it also makes it less efficient for absorbing green light at depth than is chlorophyll a. Peridinin is responsible for reflecting blue light and capturing red light. Peridinin gives peridinin its yellow-green colouration. Since peridinins have a lower affinity for green wavelengths, they appear yellow-green instead of true green as chlorophylls do. The peridinins reflect short wavelengths very well while efficiently absorbing long wavelengths, giving them their unique colouration.
Phycocyanin – Phycobiliproteins.
Phycocyanin, also known as Pigment green 7 or phycoerythrin, is a pigment that occurs in red algae and glaucophytes. The blue-green colour of certain phycobiliproteins derives from their ability to absorb light strongly at yellow/green wavelengths and weakly at red wavelengths (an example is found with chlorophylls), while phycocyanin absorbs strongly in both bands. Thus, these proteins act as a filter for those frequencies between 590 and 680 nm – which is the range most visible to humans. This absorption creates an intense blue-green colour when seen under white light. The phycobiliproteins are composed of two polypeptide chains: one called allophycocyanin, which binds phycoerythrobilin (PEB) covalently; and another called allophycocyanin reductase, which binds to PEB non-covalently.
‘Ftase And Carotenoids’.
An orange pigment is found in plants, fungi and some prokaryotes that act as an antioxidant by absorbing UV radiation. Another pigment found in many organisms is carotenoids. There are over 600 known carotenoids; they’re what gives carrots their orange colour, for example. Carotenoids protect against cancer and other diseases by reacting with free radicals and generating energy from them—similar to what happens when antioxidants neutralize harmful free radicals. manufacturer of pigment green 7, also known as chlorophyll f, is a green-coloured chlorophyll derivative mainly produced by photosynthetic bacteria called cyanobacteria that live mostly underwater bodies. It absorbs blue light and reflects red light, which makes it appear green. Other pigments include xanthophylls (yellow), phycobilins (red) and phycoerythrins (orange). Phycobilins absorb blue light at high concentrations but can reflect red or yellow light at low concentrations. Phycoerythrins are composed of phycocyanin (blue) and allophycocyanin (red). The latter is responsible for giving red algae its colour. Chlorophylls absorb blue/green light while reflecting red/yellow light.
