Photosynthesis called P680. The source of electrons for photosynthesis in green plants and cyanobacteria is water. Two water molecules are oxidized by four successive charge-separation reactions by photosystem II to yield a molecule of diatomic oxygen and four hydrogen ions. The electrons yielded are transferred to a redox-active tyrosine residue that then reduces the oxidized P680. This resets the ability of P680 to absorb another photon and release another photo-dissociated electron. The oxidation of water is catalyzed in photosystem II by a redox-active structure that contains four manganese ions and a calcium ion; this oxygen-evolving complex binds two water molecules and
What I Need to Do What I Need to Do "What I Need To Do" is a song written by Tom Damphier and Bill Luther, and recorded by American country music artist Kenny Chesney. It was released in January 2000 as the fourth and final single from Chesney's 1999 album "Everywhere We Go". The song peaked at number 8 in the United States and number 13 in Canada in 2000. The song describes the narrator thinking about "what [he] need[s] to do" as he is driving away from his old hometown away from his former lover. He also thinks that he should "turn [his] car