1. Capturing Sunlight:
* Plants contain a green pigment called chlorophyll, located within organelles called chloroplasts.
* Chlorophyll absorbs light energy, primarily in the red and blue wavelengths, while reflecting green light (which is why plants appear green).
2. Water and Carbon Dioxide Uptake:
* Plants take in water through their roots.
* They absorb carbon dioxide from the atmosphere through tiny pores on their leaves called stomata.
3. Light-Dependent Reactions:
* The absorbed light energy is used to split water molecules into hydrogen ions (H+), electrons, and oxygen.
* The oxygen is released into the atmosphere.
* The electrons and hydrogen ions are used to create energy-carrying molecules called ATP and NADPH.
4. Light-Independent Reactions (Calvin Cycle):
* The ATP and NADPH produced in the light-dependent reactions power a series of reactions in the Calvin cycle.
* Carbon dioxide from the atmosphere is incorporated into a simple sugar molecule called glucose.
* Glucose is the primary energy source for the plant and is used for growth, reproduction, and other essential functions.
Summary Equation of Photosynthesis:
6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂
In simple words:
Plants use sunlight, water, and carbon dioxide to create their own food (glucose) and release oxygen as a byproduct. This process is essential for all life on Earth, as it provides the oxygen we breathe and the food we eat.
