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In general, carotenoids absorb wavelengths ranging from 400 to 550 nanometers (violet to green light). This causes the compounds to be deeply colored yellow, orange, or red. Carotenoids are the dominant pigment in autumn leaf coloration of about 15-30% of tree species, [3] but many plant colors, especially reds and purples, are due to polyphenols.
In plants, carotenoids can occur in roots, stems, leaves, flowers, and fruits. Carotenoids have two important functions in plants. First, they can contribute to photosynthesis. They do this by transferring some of the light energy they absorb to chlorophylls, which then uses this energy for photosynthesis. Second, they can protect plants which ...
Carotenes contribute to photosynthesis by transmitting the light energy they absorb to chlorophyll. They also protect plant tissues by helping to absorb the energy from singlet oxygen , an excited form of the oxygen molecule O 2 which is formed during photosynthesis.
The carotenoids have another role as an antioxidant to prevent photo-oxidative damage of chlorophyll molecules. Each antenna complex has between 250 and 400 pigment molecules and the energy they absorb is shuttled by resonance energy transfer to a specialized chlorophyll-protein complex known as the reaction center of each photosystem . [ 1 ]
[4] [5] Ectothermic animals, which do not have their own mechanism to control body temperature, rely more on accumulation of ingested carotenoids than endotherms, which can maintain their thermal homeostasis. It is not surprising that in tissues of fish or reptiles, carotenoid concentration could be from 10 to 100 fold higher than in mammalians ...
Cyanobacteria is the only prokaryotic group that performs oxygenic photosynthesis. Anoxygenic photosynthetic bacteria use PSI- and PSII-like photosystems, which are pigment protein complexes for capturing light. [5] Both of these photosystems use bacteriochlorophyll. There are multiple hypotheses for how oxygenic photosynthesis evolved.
Lutein (/ ˈ lj uː t i ɪ n,-t iː n /; [2] from Latin luteus meaning "yellow") is a xanthophyll and one of 600 known naturally occurring carotenoids.Lutein is synthesized only by plants, and like other xanthophylls is found in high quantities in green leafy vegetables such as spinach, kale and yellow carrots.
Bacteriochlorophyll and carotenoids are two molecules responsible for harvesting light energy. Current models of the organization of bacteriochlorophyll and carotenoids (the main constituents) inside the chlorosomes have put them in a lamellar organization, where the long farnesol tails of the bacteriochlorophyll intermix with carotenoids and each other, forming a structure resembling a lipid ...