Definition and Requirements of Photosynthesis

 Photosynthesis can be defined as the formation of carbon-containing compounds from carbon dioxide

and water with the help of green pigments and light while oxygen is liberated as the by-product.

The simples equation for photosynthesis can be :



Ruben and Kamen (1941) demonstrated that the source of liberated O2 is the water, through their experiment

with oxygen isotope, 18 O as given below:



Requirements of Photosynthesis

Thus, the inputs or components of photosynthesis will be :

1. Carbon dioxide

2. Water

3. Light

4. Green pigments in chloroplasts of cells

Output of Photosynthesis

1. Carbohydrates

2. Oxygen molecules

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