Search results
Results from the WOW.Com Content Network
Photodissociation, photolysis, photodecomposition, or photofragmentation is a chemical reaction in which molecules of a chemical compound are broken down by absorption of light or photons. It is defined as the interaction of one or more photons with one target molecule that dissociates into two fragments.
The energy of P680 + is used in two steps to split a water molecule into 2H + + 1/2 O 2 + 2e-(photolysis or light-splitting). An electron from the water molecule reduces P680 + back to P680, while the H + and oxygen are released.
The difference in energy between the filled valence band and the empty conduction band in the MO diagram of a semiconductor is the band gap. [21] When the semiconductor absorbs a photon with energy equal to or greater than the material's band gap , an electron excites from the valence band to the conduction band, generating a electron hole in ...
The electron transport chain of photosynthesis is often put in a diagram called the Z-scheme, because the redox diagram from P680 to P700 resembles the letter Z. [3] The final product of PSII is plastoquinol, a mobile electron carrier in the membrane. Plastoquinol transfers the electron from PSII to the proton pump, cytochrome b6f. The ultimate ...
Photolysis by photosystem II oxidises water to oxygen, protons and electrons in the lumen. The transfer of electrons from photosystem II to plastoquinone during non-cyclic electron transport consumes two protons from the stroma. These are released in the lumen when the reduced plastoquinol is oxidized by the cytochrome b6f protein complex on ...
Photoexcitation is the first step in a photochemical process where the reactant is elevated to a state of higher energy, an excited state.The first law of photochemistry, known as the Grotthuss–Draper law (for chemists Theodor Grotthuss and John W. Draper), states that light must be absorbed by a chemical substance in order for a photochemical reaction to take place.
Flash photolysis is a pump-probe laboratory technique, in which a sample is first excited by a strong pulse of light from a pulsed laser of nanosecond, picosecond, or femtosecond pulse width or by another short-pulse light source such as a flash lamp.
The Barton reaction, also known as the Barton nitrite ester reaction, is a photochemical reaction that involves the photolysis of an alkyl nitrite to form a δ-nitroso alcohol. Discovered in 1960, the reaction is named for its discoverer, Nobel laureate Sir Derek Barton. [1]