<human>:  How does the process of photosynthesis work on a cellular level?
<bot>: Photosynthesis is the process in which energy from sunlight is converted into chemical energy. On a cellular level, the process of photosynthesis occurs in two stages, called the light-dependent reaction and the Calvin cycle. During the light-dependent reaction, energy from the sun is absorbed by pigments in the chloroplasts of plant cells, including chlorophyll and carotenoids. This energy is then used to split water molecules into oxygen, hydrogens, and protons. The protons and electrons then enter the electron transport chain, which produces ATP and NADPH. The NADPH and ATP are then used in the Calvin cycle to reduce carbon dioxide into glucose.