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A Quantum Chemical Study of Hydrogen Abstraction from Manganese-Coordinated Water by a Tyrosyl Radical: A Model for Water Oxidation in Photosystem II

Recently, water oxidation in photosystem II was proposed to involve direct abstraction of hydrogen atoms from water molecules terminally ligated to manganese ions in the oxygen-evolving complex by the oxidized tyrosine radical, TyrZ. This model is tested here by performing quantum chemical calculations. An empirically parametrized hybrid density functional method is used, and both monomeric and di

Effects of ultraviolet radiation on marine phytoplankton

This thesis examines the effects of artificial and solar ultraviolet radiation on photosynthesis, growth rate, phototactic orientation and motility of marine phytoplankton. The effects of UV-B (280-320 nm) radiation in combination with humic substances, as well as the ability of the organisms to adapt and/or recover from exposure to UV-B radiation, were also investigated. Phototactic orientation a