1 - Chloroplasts (fluorescence of chlorophyll), 2 - mitochondria stained with rhodamine dye, 3 - ROS (fluorescence of 2',7'-dichlorofluorescein), 4 - joint image of chloroplasts, mitochondria and ROS.

The sun is the ultimate source of energy for virtually all organisms. Photosynthetic cells are able to use solar energy to synthesize energy-rich food molecules and to produce oxygen.