Explanation:

Plants and other photosynthetic organisms are experts at collecting solar energy, thanks to the light-absorbing PIGMENT molecules in their leaves. But what happens to the light energy that is absorbed? We don’t see PLANT leaves GLOWING LIKE light bulbs, but we also know that energy can't just disappear (thanks to the First Law of Thermodynamics).

As it turns out, some of the light energy absorbed by pigments in leaves is converted to a different form: chemical energy. Light energy is converted to chemical energy during the first stage of photosynthesis, which involves a series of chemical reactions known as the light-dependent reactions.

In this article, we'll explore the light-dependent reactions as they take place during photosynthesis in plants. We'll trace how light energy is absorbed by pigment molecules, how reaction center pigments pass excited electrons to an electron transport chain, and how the energetically "downhill" flow of electrons leads to synthesis of ATP and NADPH. These molecules store energy for use in the next stage of photosynthesis: the Calvin cycle.