Photosynthesis occurs primarily in the chloroplasts of plant cells. These organelles contain chlorophyll, the green pigment that captures sunlight and plays a crucial role in the conversion of carbon dioxide and water into glucose and oxygen.
The process can be divided into two main stages: the light-dependent reactions and the light-independent reactions (Calvin cycle). The light-dependent reactions take place in the thylakoid membranes of the chloroplasts, where sunlight is absorbed and converted into chemical energy in the form of ATP and NADPH. Meanwhile, the light-independent reactions occur in the stroma, the fluid-filled space surrounding the thylakoids, where the energy from ATP and NADPH is used to synthesize glucose from carbon dioxide.
In summary, photosynthesis mainly happens in the chloroplasts of plant cells, utilizing both the thylakoid membranes and the stroma to transform light energy into chemical energy.