What does the reaction center complex do?
What does the reaction center complex do?
The reaction centre contains pigments such as chlorophyll and phaeophytin. These absorb light, promoting an electron to a higher energy level within the pigment. The free energy created is used to reduce an electron acceptor and is critical for the production of chemical energy during photosynthesis.
What is P680 and P700?
The special pair of photosystem I is called P700, while the special pair of photosystem II is called P680. When light is absorbed by one of the pigments in photosystem II, energy is passed inward from pigment to pigment until it reaches the reaction center.
What is the role of the light-harvesting complex?
The main function of the light-harvesting complexes is to gather light energy and to transfer this energy to the reaction centers for the photo-induced redox processes.
What is unique about the reaction center chlorophyll?
Reaction center chlorophyll-protein complexes are capable of directly absorbing light and performing charge separation events without other chlorophyll pigments, but the absorption cross section (the likelihood of absorbing a photon under a given light intensity) is small.
What do the reaction center chlorophyll and the primary electron acceptor do in the reaction center?
The reaction center contains a pair of chlorophyll a molecules with a special property. The reaction center of PSII (called P680) delivers its high-energy electrons, one at the time, to the primary electron acceptor, and through the electron transport chain (Pq to cytochrome complex to plastocyanin) to PSI.
What is the role of Plastocyanin?
Plastocyanin is a copper-containing protein that mediates electron-transfer. It is found in a variety of plants, where it participates in photosynthesis. The protein is a prototype of the blue copper proteins, a family of intensely blue-colored metalloproteins.
What is P680 reaction center?
The reaction center chlorophyll (or the primary electron donor) of photosystem II that is most reactive and best in absorbing light at wavelength of 680 nm. Supplement. P680 is a group of pigments that are excitonically coupled or that act as if the pigments are a single molecule when they absorb a photon.
Which of the following acts as a reaction center during photosynthesis?
Out of this, chlorophyll a is the major pigment involved in photosynthesis and it forms the reaction centre.
What are the functions of light-harvesting and reaction center chlorophylls?
A photosystem consists of a light-harvesting complex and a reaction center. Pigments in the light-harvesting complex pass light energy to two special chlorophyll a molecules in the reaction center. The light excites an electron from the chlorophyll a pair, which passes to the primary electron acceptor.
What role does the antenna complex play in the absorption of photons and excitation of electrons?
The first act of photosynthesis is the absorption of photons by antenna molecules (within femtoseconds), leading to the formation of excited chlorophyll molecules (Chl*). Another crucial function of antenna complexes is to serve as a safety valve for the thermal dissipation of excess absorbed light energy.
What is the role of chlorophyll and other pigments in the reaction center?
The electron flow produced by the reaction center chlorophyll pigments is used to pump H+ ions across the thylakoid membrane, setting up a chemiosmotic potential used mainly in the production of ATP (stored chemical energy) or to reduce NADP+ to NADPH.
