In Brief
Researchers have captured a "movie" of the energy transfer that takes place during photosynthesis, disproving a long-held belief about the quickest part of the process. By bettering our understanding of natural photosynthesis, we can improve our artificial systems, which could provide the world with a free, unlimited energy supply.

Photosynthesis on Film

With the help of sophisticated lasers and infrared spectroscopy, researchers from Imperial College London have captured the chemical reactions that take place during photosynthesis. And, these processes happen seriously fast. “We can now see how nature has optimized the physics of converting light energy to fuel,” study author Jasper van Thor said in a news release.

The team’s study was focused on understanding the Photosystem II enzyme reaction. During that part of photosynthesis, light energy is used to split water into hydrogen and oxygen. Prior to this study, that process was presumed to be the slowest part of the process.

The team at Imperial College was able to prove otherwise by creating crystals of the Photosystem II enzyme and shooting them with lasers. By recording the process using infrared spectroscopy, they were able to demonstrate that the Photosystem II enzyme reaction takes place more quickly than the first part of photosynthesis when light is harvested by proteins and chlorophyll molecules.

Dr. Jasper van Thor working on the ultrafast spectroscopy. Image Credit: Imperial College London

Looking to Nature for Answers

Not only have the researchers disproven the long-held belief that the harvesting process was faster than the Photosystem II reaction, they’ve also captured the process on film. Given that each process takes place in just picoseconds (trillionths of a second), the “movie” they’ve recorded is no longer than a few nanoseconds (billionths of a second), but that’s long enough to give scientists a better understanding of photosynthesis.

“We can now see how nature has optimized the physics of converting light energy to fuel, and can probe this process using our new technique of ultrafast crystal measurements,” said van Thor. “For example, is it important that the bottleneck occurs at this stage, in order to preserve overall efficiency? Can we mimic it or tune it to make artificial photosynthesis more efficient? These questions, and many others, can now be explored.”

Unlike current solar energy systems, artificial photosynthesis converts solar energy into a storable fuel. If we can use these new insights into photosynthesis to improve artificial photosynthesis, it could drastically improve solar energy technology and go a long way toward alleviating a number of the world’s problems. We could reduce global warming, help to end hunger here on Earth, and perhaps even help us to survive as a species in space. As long as we have the Sun, we would have a free, unlimited source of energy.