Tha anatomy of photosynthetic cells is adapted to trapping sunlight, and their physiology effectively uses this solar energy to produce high-energy glucose from low-energy co2 and water. photosynthetic organisms achieve this remarkable feat through a series of reactions involving light, pigment, co2, and water, which is used as a source for electrons.
photosynthesis proceeds in two phases: the light-dependent reactions, which proceed only in the presence of sunlight, and the light-independent reactions, which proceed regardless of the lighting conditions ( light or dark ) ( figure 8.28 ).