The CO2 is then available for light-dependent reactions in the daytime, and stomata close, reducing the risk of water loss.

The reaction is supported by a "helper molecule" which stepwise delivers two electrons. Up to now, it had been assumed that such a light-dependent reaction cannot occur in enzymes. "The enzyme we ...

Discovered around half a century ago, the Fd/Trx pathway has long been credited with regulating many light dependent reactions in chloroplasts, the organ in the leaf where photosynthesis occurs.