Photosynthesis may involve quantum mechanical processes

BBC : Plants may exhibit signs of quantum coherent energy transfer while undergoing photosynthesis. That finding is from a study published in Science and written by Niek van Hulst of the Institute of Photonic Sciences in Castelldefels, Spain, and colleagues. To observe how light-harvesting complexes in organisms function, the researchers shot lasers at single molecules in purple bacteria, which derive energy from photosynthesis. They observed that the light was absorbed by a series of antenna-like structures arranged in adjacent rings. The individual photons were then observed to consistently follow the most efficient pathways to the bacteria’s reaction centers, where the light is converted into chemical energy. That task is complicated by the fact that multiple possible paths exist, and because conditions in living things are constantly changing, the most efficient pathways for energy to flow are also constantly changing. The researchers propose that the photons absorbed by a plant’s cells exist for a brief time in a superposition of states, in which they try multiple routes simultaneously to determine the most energy-efficient one.