What is linear electron flow?
In linear electron flow (LEF), electrons from the splitting of water by the oxygen-evolving complex (OEC) are transferred to NADP+, reducing NADP+ to NADPH.
What happens during linear electron transport?
Linear electron transport results in the formation of reductant and ATP, while cyclic electron transport results only in the formation of ATP with no net formation of reductant. The flux of electrons through these pathways is regulated at the level of the cytb6f complex.
How does linear electron flow produce ATP and NADPH?
As electron move down the chain, their exergonic “fall”to a lower energy level is harnessed by the thylakoid membrane to produce ATP (by chemiosmosis). An enzyme reaction transfers the electrons from the protein to NADP+ that forms NADPH (which has high chemical energy due to the energy of the electrons).
Why is it called P680?
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. It derived its name after the wavelength (in nanometers) at which it is best in capturing. In this case, it is the 680 nm of the electromagnetic spectrum.
What are the 8 major steps in the linear flow of electrons in photosynthesis?
Terms in this set (8)
- Photon hits the light-harvesting complex in PSII and excites the electrons in chlorophyll a.
- Excited electron goes into the primary electron acceptor, Results in P680+
- Water splits in oxygen – 2 electrons – 2 H+, H+ goes into the lumen, Electrons feed into P680+
What are the products of linear electron flow?
The products of linear electron flow are ATP and NADPH.
Where does linear electron flow occur?
In linear electron flow (unbroken arrows) energy from absorbed photons is used to oxidise water on the luminal face of photosystem II (PS II). Electrons generated by this process pass through a series of electron carriers in PS II and then to the oxidized plastoquinones (PQ) that diffuse within the membrane.
Where is P700 found?
P700, or photosystem I primary donor, is the reaction-center chlorophyll a molecular dimer associated with photosystem I in plants, algae, and cyanobacteria.
What is P700 and P680?
Photosystems, large complexes of proteins and pigments (light-absorbing molecules) that are optimized to harvest light, play a key role in the light reactions. The special pair of photosystem I is called P700, while the special pair of photosystem II is called P680.