by Diane Boudreau

Photosynthesis is the main life process on Earth. Through photosynthesis, plants convert light energy from the sun into chemical energy. Two photosystems catalyze the first step of this energy conversion.

Photosystem I (PS I) captures light energy from the sun using a large, complex antenna system. The antenna system transfers light energy to the core of the complex with more than 99.99 percent efficiency.

This image shows the structure of PS I in the cyanobacterium Synechococcus elongatus. The image was created from information obtained by crystallizing the photosystem and then shining an x-ray through the crystal to produce a diffraction pattern.

Image courtesy Petra Fromme, Ph.D.

To learn more about photosynthesis research at ASU, see "Catching some rays."