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Photosystem II obtains electrons by oxidizing water in a process called photolysis. Molecular oxygen is a byproduct of this process, and it is this reaction that supplies the atmosphere with oxygen. The fact that the oxygen from green plants originated from water was first deduced by the Canadian-born American biochemist Martin David Kamen.
Like plants, the cyanobacteria use water as an electron donor for photosynthesis and therefore liberate oxygen; they also use chlorophyll as a pigment.In addition, most cyanobacteria use phycobiliproteins, water-soluble pigments which occur in the cytoplasm of the chloroplast, to capture light energy and pass it on to the chlorophylls.
In bacteria, the special pair is called P760, P840, P870, or P960. "P" here means pigment, and the number following it is the wavelength of light absorbed. Electrons in pigment molecules can exist at specific energy levels. Under normal circumstances, they are at the lowest possible energy level, the ground state.
One approach involves incorporating pigments like chlorophyll d and f, which are capable of absorbing far-red light, into the photosynthetic machinery of higher plants. [16] Naturally present in certain cyanobacteria, these chlorophylls enable photosynthesis with far-red light that standard chlorophylls a and b cannot utilize. By adapting these ...
The antenna pigments are predominantly chlorophyll b, xanthophylls, and carotenes. Chlorophyll a is known as the core pigment. Their absorption spectra are non-overlapping and broaden the range of light that can be absorbed in photosynthesis. The carotenoids have another role as an antioxidant to prevent photo-oxidative damage of chlorophyll ...
The pigments are red in combination with Be 2+ and Ga 3+. The pigment is deep purple or reddish-brown in combination with Fe 3+ . Color of a particular pigment in acidic solutions may change: aluminon and Sc 3+ form red pigments if the solution is acidic, but otherwise the solutions are colorless.
P680 + is the strongest biological oxidizing agent known, with an estimated redox potential of ~1.3 V. [3] This makes it possible to oxidize water during oxygenic photosynthesis. P680 + recovers its lost electron by oxidizing water via the oxygen-evolving complex , which regenerates P680.
Modern 'open system' photosynthesis systems remove the CO 2 and water vapour by passage over soda lime and Drierite, then add CO 2 at a controlled rate to give a stable CO 2 concentration. [1] Some systems are also equipped with temperature control and a removable light unit, so the effect of these environmental variables can also be measured.