Light-gathering macromolecules in plant cells transfer energy by taking advantage of molecular vibrations whose physical descriptions have no equivalents in classical physics, according to the first unambiguous theoretical evidence of quantum effects in photosynthesis, published in the journal Nature Communications (open access).
The majority of light-gathering macromolecules are composed of chromophores (responsible for the color of molecules) attached to proteins, which carry out the first step of photosynthesis, capturing sunlight and transferring the associated energy highly efficiently.
Previous experiments have suggested that energy is transferred in a wave-like manner, exploiting quantum phenomena, but crucially, a non-classical (quantum) explanation could not be conclusively proved because the phenomena identified could equally be described using classical physics.
Non-classicality of the molecular vibrations assisting exciton energy transfer at room temperature
- Nature Communications
- 5,
- Article number:
- 3012
- doi:10.1038/ncomms4012
- Received
- Accepted
- Published
Advancing the debate on quantum effects in light-initiated reactions in biology requires clear identification of non-classical features that these processes can exhibit and utilize. Here we show that in prototype dimers present in a variety of photosynthetic antennae, efficient vibration-assisted energy transfer in the sub-picosecond timescale and at room temperature can manifest and benefit from non-classical fluctuations of collective pigment motions. Non-classicality of initially thermalized vibrations is induced via coherent exciton–vibration interactions and is unambiguously indicated by negativities in the phase–space quasi-probability distribution of the effective collective mode coupled to the electronic dynamics. These quantum effects can be prompted upon incoherent input of excitation. Our results therefore suggest that investigation of the non-classical properties of vibrational motions assisting excitation and charge transport, photoreception and chemical sensing processes could be a touchstone for revealing a role for non-trivial quantum phenomena in biology.
A less-expensive way to duplicate the complicated steps of photosynthesis in making fuel
| January 23, 2014 |
 | Argonne National Laboratory researchers have found a new, more efficient, less-expensive way to make fuel — principally, hydrogen — from sunlight and water: linking a synthetic cobalt-containing catalyst to an organic light-sensitive molecule called a chromophore. Chromophore molecules, such as chlorophyll, are involved in capturing light for photosynthesis. Currently, the most efficient methods we have … more… |
No comments:
Post a Comment