Deep within plants' energy-harvesting machinery lie distinctly quantum tricks
The idea that plants make use of
quantum physics to harvest light more efficiently has received a boost.
Plants gather packets of light called photons, shuttling them deep into their
cells where their energy is converted with extraordinary efficiency.
A report
in Science journal adds weight to the idea that an effect called a
"coherence" helps determine the most efficient path for the photons.
Experts have called the work "a nice proof" of some contentious ideas.
Prior work has shown weaker evidence that these coherences existed in
relatively large samples from plants.
But the new study has been done painstakingly, aiming lasers at single
molecules of the light-harvesting machinery to show how light is funnelled to
the so-called reaction centres within plants where light energy is converted
into chemical energy.
What has surprised even the researchers behind the research is not only that
these coherences do indeed exist, but that they also seem to change character,
always permitting photons to take the most efficient path into the reaction
centres.
Until very recently, quantum mechanics - a frequently arcane branch of
physics most often probed in laboratory settings at the coldest temperatures and
lowest pressures - would not have been expected in biological settings.
The fact that plants and animals are extremely warm and soft by comparison
would suggest that delicate quantum states should disappear in living things,
leaving behaviour explicable by the more familiar "classical physics" that is
taught in school.
But the new results join the ranks of a field that seems
finally to be gaining ground: quantum biology.
