What is photosynthesis in simple words?

Photosynthesis is the process by which green plants make their own food using sunlight, carbon dioxide, and water. The plant uses chlorophyll to absorb sunlight, combines CO₂ from air with water from soil, and produces glucose (food) and oxygen. Equation: 6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂.

Where does photosynthesis take place in the cell?

Photosynthesis takes place in the chloroplasts — organelles found in the cells of green leaves. Inside chloroplasts, the light reactions occur in the thylakoids and the dark reactions (Calvin cycle) occur in the stroma.

What are the factors that affect the rate of photosynthesis?

The four main factors are: (1) Light intensity — more light increases rate up to a saturation point, (2) CO₂ concentration — higher CO₂ increases rate, (3) Temperature — optimal at 25-30°C, (4) Water availability — deficiency causes stomata to close, reducing CO₂ intake.

Photosynthesis Explained

Photosynthesis Explained • Class 9 Science • NCERT • CBSE

Photosynthesis is the process by which green plants make their own food using sunlight, carbon dioxide, and water. The equation is: 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂. Chlorophyll in leaves absorbs sunlight to power this reaction.

Key Formulas

6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂ (Photosynthesis equation)
H₂O → 2H⁺ + ½O₂ + 2e⁻ (Photolysis of water)
Chlorophyll absorbs red (680 nm) and blue (430 nm) light

Frequently Asked Questions

What is photosynthesis in simple words?: Photosynthesis is the process by which green plants make their own food using sunlight, carbon dioxide, and water. The plant uses chlorophyll to absorb sunlight, combines CO₂ from air with water from soil, and produces glucose (food) and oxygen. Equation: 6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂.
Where does photosynthesis take place in the cell?: Photosynthesis takes place in the chloroplasts — organelles found in the cells of green leaves. Inside chloroplasts, the light reactions occur in the thylakoids and the dark reactions (Calvin cycle) occur in the stroma.
What are the factors that affect the rate of photosynthesis?: The four main factors are: (1) Light intensity — more light increases rate up to a saturation point, (2) CO₂ concentration — higher CO₂ increases rate, (3) Temperature — optimal at 25-30°C, (4) Water availability — deficiency causes stomata to close, reducing CO₂ intake.

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