Photosynthesis happens in two main phases: the light-dependent reactions and the light-independent reactions (also known as the Calvin cycle). Here’s what happens in each phase:
### 1. Light-Dependent Reactions:
- **Where:** Happens in the thylakoid membranes of the chloroplasts.
- **What Happens:**
- Plants take in sunlight.
- The sunlight energy splits water (H2O) into hydrogen and oxygen.
- Oxygen is released into the air.
- The energy from sunlight makes energy-rich molecules called ATP and NADPH.
### 2. Light-Independent Reactions (Calvin Cycle):
- **Where:** Happens in the stroma of the chloroplasts.
- **What Happens:**
- Uses ATP and NADPH made from the first phase.
- Takes carbon dioxide (CO2) from the air.
- Combines hydrogen (from water) with carbon dioxide to make glucose (a type of sugar).
- Glucose is used by the plant for energy and growth.
In short, the first phase captures light and makes energy, while the second phase uses that energy to create food for the plant!