Magazine article Science News

Quantum Capture: Photosynthesis Tries Many Paths at Once

Magazine article Science News

Quantum Capture: Photosynthesis Tries Many Paths at Once

Article excerpt

Quantum physics plays a larger role than scientists had expected in plants' capture of light. New findings could explain life's uncannily efficient use of solar energy, researchers say.

In organisms ranging from blue algae to giant sequoias, complicated assemblies of molecules of the pigment chlorophyll absorb sunlight's photons and channel their energy to enable the plants to turn water and carbon dioxide into oxygen and sugars.

The efficiency of photosynthesis, as this process is called, has long astounded scientists. Virtually every photon absorbed by chlorophyll initiates a photosynthetic reaction. Plants use up to 90 percent of the light that strikes them, whereas commercial solar panels use less than 30 percent.

The absorption of a photon causes a chlorophyll molecule to enter an excited state, in which one or more of its electrons hop to a higher energy level. The traditional view was that chlorophyll molecules within a complex swap excitations until that energy finds its way to a reaction center, where it initiates a chemical reaction. But at each exchange between molecules, the excitation might dissipate as waste heat, so scientists didn't understand how the process could be so efficient.

Instead of bouncing from one molecule to another, excitations move like waves do, reports a team of chemists at the University of California, Berkeley and the Lawrence Berkeley National Laboratory. In a new experiment, Greg Engel and his colleagues found that groups of chlorophyll molecules spend a surprisingly long time in a so-called superposition of states--a quantum phenomenon in which many molecules share excitation energy and so are simultaneously excited and relaxed. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.