What is photo oxidation in plants?
The light‐dependent generation of active oxygen species is termed photooxidative stress. This can occur in two ways: (1) the donation of energy or electrons directly to oxygen as a result of photosynthetic activity; (2) exposure of tissues to ultraviolet irradiation.
What is photo oxidation of chlorophyll A?
Photo -oxidation in chlorophyll a means release of electrons from Chlorophylla (PSII/P680) after absorption of a photon. It occurs during noncyclic photophosphorylation. … The oxidised Chlorophyll a accepts electron from donor (H2O) and this results in synthesis of molecular oxygen from water.
What is meant by photo oxidation?
Photo-oxidation is the degradation of a polymer surface in the presence of oxygen or ozone. The effect is facilitated by radiant energy such as UV or artificial light. This process is the most significant factor in weathering of polymers. Photo-oxidation is a chemical change that reduces the polymer’s molecular weight.
What causes photodegradation?
Photodegradation is degradation of a photodegradable molecule caused by the absorption of photons, particularly those wavelengths found in sunlight, such as infrared radiation, visible light, and ultraviolet light. However, other forms of electromagnetic radiation can cause photodegradation.
What is photo oxidation of water?
PHOTO OXIDATION OF WATER:- • The PS-II reaction centre (P680) by transferring electron to primary acceptor becomes oxidised. • The overall process is called photo-oxidation of water. It requires the presence of Mn++, Ca+ and Cl- , a water oxidising enzyme and an unknown substance Z.
What is the definition of oxidation?
Oxidation is loss of electrons (OIL RIG). That means that an oxidising agent takes electrons from that other substance. So an oxidising agent must gain electrons.
What is Photooxidative damage?
The light-dependent generation of active oxygen species is termed photooxidative stress. This can occur in two ways: (1) the donation of energy or electrons directly to oxygen as a result of photosynthetic activity; (2) exposure of tissues to ultraviolet irradiation.
Which pigment can protect chlorophyll from Photooxidative damage?
How do carotenoids protect chlorophyll?
Carotenoids Absorb In Wavelengths that Chlorophyll Does Poorly In. Meanwhile, the carotenoids are absorbing maximally at those wavelengths where chlorophyll does poorly (light blue to green). Once that light energy is absorbed, the carotenoids pass that energy on to a neighboring chlorophyll molecule.
What is a photolysis?
Photolysis (also called photodissociation and photodecomposition) is a chemical reaction in which an inorganic chemical (or an organic chemical) is broken down by photons and is the interaction of one or more photons with one target molecule.
How does accessory pigments protect chlorophyll A from Photooxidation?
Photo-oxidation is the process of oxidation induced by light. … In plants, accessory pigments like zeaxanthin, a carotenoid belonging to the group of xanthophylls and chlorophyll b protects the chlorophyll a from photo-oxidation.
What is the definition of photosynthesis?
Photosynthesis takes in the carbon dioxide produced by all breathing organisms and reintroduces oxygen into the atmosphere. (Image: © KPG_Payless | Shutterstock) Photosynthesis is the process used by plants, algae and certain bacteria to harness energy from sunlight and turn it into chemical energy.
What are the effects of photodegradation?
Photodegradation causes chain scission in the polymer material which results in the loss of important physical properties such as impact strength, tensile strength, elongation at break, etc. and can be observed as cracking, chalking and color changes.
Does light cause oxidation?
UV radiation is provided by UV light bulbs Oxidation of target contaminants is caused by direct reaction with the oxidizers (for example, see description of Peroxone), and through the action of UV light in combination with ozone and/or hydrogen peroxide.