🌱 Plant Life
Photosynthesis, transpiration, plant parts.
💡 How Plants Make Their Own Food
Plants are autotrophs — they make their own food using sunlight. This process is photosynthesis:
Six molecules of CO₂ + six of water + sunlight → one glucose molecule + six oxygen molecules. This happens in the chloroplasts using the green pigment chlorophyll.
Parts of a plant and their jobs:
• Roots — absorb water and minerals, anchor the plant
• Stem — transports water/food, supports the plant
• Leaves — the "kitchen" — photosynthesis happens here
• Flowers — reproduction
• Fruits/seeds — protect and disperse next generation
Water evaporates from leaf surfaces (mainly through tiny pores called stomata). This creates a "pull" that draws water all the way up from roots — like sucking through a straw.
A single large tree can transpire 200-450 litres of water per day. That's why forests cool their surroundings.
Plants do BOTH:
• Photosynthesis — daytime — takes in CO₂, releases O₂
• Respiration — 24/7 — takes in O₂, releases CO₂
During the day, photosynthesis > respiration, so net release is O₂. At night, only respiration happens.
Chlorophyll absorbs red and blue light but reflects green light — that's why leaves look green to us.
The actual sites of photosynthesis are tiny stacks of disc-shaped membranes inside chloroplasts called thylakoids (stacked into grana).
Photosynthesis in Action
AnimationPlants pull water from roots, CO₂ from leaves, sunlight from above — and make sugar + oxygen.
What Affects Photosynthesis?
InteractiveAdjust the conditions and see how photosynthesis rate changes.
1. Allow CO₂ in for photosynthesis
2. Release O₂ and water vapor (transpiration)
They open in daylight and close at night to prevent water loss. Each stoma has 2 guard cells that open or close it.