# Photosynthesis: A Complete Overview

## Basic Definition
Photosynthesis is the process where plants, algae, and some bacteria convert light energy into chemical energy stored in glucose, releasing oxygen as a byproduct.

**Simple equation:**
6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂

## Two Main Stages

### 1. **Light-Dependent Reactions** (Thylakoid membranes)
- Occur in daylight
- Use photons to excite electrons in chlorophyll
- Split water molecules (photolysis), releasing oxygen
- Produce energy carriers: ATP and NADPH
- Power source for the next stage

### 2. **Light-Independent Reactions** (Calvin Cycle, in stroma)
- Occur in light or darkness
- Use ATP and NADPH from stage 1
- Fix CO₂ into 3-phosphoglycerate
- Build glucose molecules
- Regenerate RuBP to continue the cycle

## Key Components
- **Chlorophyll**: Absorbs light (peaks in blue and red wavelengths)
- **Thylakoids**: Stacked membrane structures where light reactions occur
- **Stroma**: Fluid-filled space where Calvin cycle happens
- **Photosystems I & II**: Protein complexes capturing light energy

## Factors Affecting Rate
- Light intensity
- CO₂ concentration
- Temperature
- Water availability
- Chlorophyll amount

## Significance
- Produces ~90% of Earth's oxygen
- Forms base of most food chains
- Stores solar energy in chemical bonds
- Critical for all aerobic life

Any specific aspect you'd like me to explore deeper?
