Light energy is converted into
chemical energy through the light reactions of photosynthesis. A
pigment molecule absorbs a photon of light, which excites an
electron in the pigment molecule to a higher energy level.
This excitation energy is
transmitted to a reaction center where it drives the transfer of an
electron from chlorophyll to a molecule in the electron transport
chain. As the electron moves through the transport chain, protons
are pumped into the lumen of the thylakoids.
In this Lesson, well learn
how electrons reduce NADP, and how ATP is synthesized when the
protons exit the lumen. Reduced NADP (NADPH) and ATP contain
chemical energy thats used to synthesize carbohydrates from
carbon dioxide in the light-independent, or dark, reactions of