Where Does Photosynthesis Happen? 🌱
📍 The “Where” Question
Photosynthesis mainly happens in the green leaves of plants, but guess what? It also happens in other green parts! Can you think of some? (Hint: What about young stems or unripe fruits?) 🍃
🔬 The Chloroplast Connection
Inside plant cells (especially mesophyll cells in leaves), tiny green structures called chloroplasts do all the hard work! They line up along cell walls to catch the perfect amount of sunlight. Fun thought: When might they lie flat against the wall? When might they stand upright? 🤔
🏗️ Chloroplast Structure = Teamwork!
Check out what’s inside a chloroplast (Figure 11.2):
- Membranous System (made of grana + stroma lamellae): Traps light ⚡ and makes ATP + NADPH (energy molecules!).
- Stroma (fluid matrix): Uses ATP & NADPH to make sugar → which becomes starch! 🌾
⚡ Two Reaction Types
- Light Reactions (Photochemical):
- Need light directly ☀️
- Happen in the membranous system
- Make ATP & NADPH
- Dark Reactions (Carbon Reactions):
- Don’t need light directly (but need ATP & NADPH from light reactions!)
- Happen in the stroma
- Make sugar → starch 🍬
- ⚠️ Note: They can happen in light! “Dark” just means “not directly needing light.”
📝 NEET Quick Bites (Must-Know!)
- ✅ Site: Photosynthesis happens in chloroplasts, found mainly in green leaves 🌿 and other green plant parts.
- ✅ Chloroplast Structure: Know grana (for light reactions) vs. stroma (for sugar-making).
- ✅ Light Reactions: Produce ATP & NADPH in thylakoid membranes (grana).
- ✅ Dark Reactions: Use ATP & NADPH to fix carbon → sugar in the stroma.
- ✅ Misconception Alert: “Dark reactions” ≠ “only in dark!” They rely on light-reaction products.
Keep rocking your bio journey! 💚 Every green part of a plant is a tiny solar-powered factory!
