Scientists observe elusive missing step in photosynthesis’ final stage
Researchers at the SLAC National Accelerator Laboratory and Lawrence Berkeley National Laboratory (along with collaborators in Sweden, Germany and the UK) have shed new light on the final step of photosynthesis. They observed in atomic detail how Photosystem II, a protein complex found in plants, undergoes a transformation that leads to the loss of an extra oxygen atom. Scientists believe the discoveries will help provide a roadmap for optimizing clean energy sources. “It’s really going to change the way we think about Photosystem II,” said Uwe Bergmann, scientist and professor at the University of Wisconsin-Madison, who co-authored the paper.
Researchers took “extremely high-resolution images” of different stages of the process (at room temperature), giving them new insight into specifically how and where the oxygen is produced. Baseball can provide a simple (if somewhat forced) metaphor to illustrate the process. “The center cycles through four stable oxidation states, known as S0 through S3, when exposed to sunlight,” SLAC explains. “On a baseball field, S0 would be the start of the game when a player on home base is ready to go to bat. S1-S3 would be players on first, second, and third.” Based on this metaphor, a batter making contact …read more
