February 8, 2010 | Source: The Scientist
Physical chemist Gregory Scholes of the University of Toronto and his colleagues have observed that energy introduced to light-harvesting systems of two species of photosynthetic algae acted in a distinctly quantum manner, even at ambient temperatures.
In these algae, bilin pigments, like other light-harvesting antenna molecules, absorb solar photons, which excite their electrons. The resulting excitation energy then moves to complexes of proteins called reaction centers, where it is converted to chemical energy by a series of biochemical events. While classical energy transfer theory predicts that the energy “hops, hops, hops” from one molecule to the next in a kind of “random walk,” Scholes explained, quantum theory predicts that energy flows through the system in a much more spread-out, directed fashion.
The wave-like motion provides the energy with a “memory” of where it’s been that eliminates some of the randomness of how it moves through the cell.