Functions of carotenoids in photosynthesis
How carotenoids function in photosynthetic ..
Among CARs β-carotene and several xanthophylls serve as constituents of functional multiprotein complexes, such as photosystems I and II (PSI, PSII), cytochrome b 6 / f complexes, and the light-harvesting complexes involved in photosynthetic electron transport.
BBA 86145 How carotenoids function in photosynthetic bacteria ..
The complex of regulatory reactions based on negative and positive feedback principles provides prolonged functioning of a chloroplast and high stability of photosynthetic activity under various light conditions.">
chlorophylls and carotenoids with peaks ..
Their specific colour depends on metal ions and pH.
• Carotenoids are lipid-soluble pigments, and are involved in harvesting light in photosynthesis.
In vivo functions of carotenoids ..
Light energy in the form of photons is harvested by systems of in pigment molecules. Because each pigment can only absorb photons with an energy that exactly matches the amount to excite an electron to an excited state, each pigment has a characteristic color. Both chlorophyll and carotenoid pigments are produced in biosynthetic pathways that also produce other important biomolecules.
The chlorophyll and carotenoid molecules are organized in the membranes into two photosystems. Most of the pigments in each act as and harvest light. A few specialized pigments form the reaction centers and carry out the photochemical electron transfers. Absorption of light by the two photosystems excites electrons in two steps and transfers them from water to the NADPH; two photosystems are required because the energy difference between the electrons in water and NADPH is greater than the energy in a single . Simultaneously, the pumps protons across the photosynthetic membrane, providing the energy to synthesize ATP. With sufficient quantities of NADPH and ATP, the chloroplast is able to complete the process of photosynthesis by producing sugars from CO2.