How many main steps are involved in photosynthesis?

Photosynthesis primarily consists of two main stages: the light-dependent reactions and the light-independent reactions, commonly referred to as the Calvin cycle.

In the light-dependent reactions, which take place in the thylakoid membranes of the chloroplasts, solar energy is captured and used to generate ATP and NADPH, while water is split to release oxygen. This stage is crucial for converting light energy into chemical energy in the form of ATP and NADPH.

The second stage, the light-independent reactions (Calvin cycle), occurs in the stroma of the chloroplasts. Here, the ATP and NADPH produced in the first stage are utilized to convert carbon dioxide into glucose through a series of enzymatic reactions.

The clear division into these two stages highlights the efficiency and complexity of photosynthesis, reflecting how light energy is converted to chemical energy and then used for carbon fixation. This understanding underscores the significance of both phases working in concert to fuel plant life and, by extension, all life on Earth through the process of photosynthesis.