All living being in order to sustain life requires food. We human beings get our food directly or indirectly from plants. But the green plants in order to stay alive make their own food, the scientific process by which plants prepare their food is termed as PHOTOSYNTHESIS. The word “photo” means light and the word “synthesis” means putting together. Photosynthesis is a process by which phototrophs convert light energy into chemical energy, which is later used to fuel cellular activities.
The plant cells prepare their own food and for this process they primarily require some inorganic raw materials:
I. Carbon dioxide (CO<sub>2</sub>)
II. Water (H<sub>2</sub>O)
Ø Plants absorb water from the soil through the roots, they intake the carbon dioxide from the environment through the stomatal pores present in the leaves.
Ø These stomatal pores are surrounded by a pair of guard cells and helps in releasing the oxygen which is produced during photosynthesis.
Ø With the help of Carbon dioxide and water in presence of the green pigment named chlorophyll in their leaves and sunlight the plants produce carbohydrates, which from the leaves are then transported into each and every part of the plant. The extra carbohydrates are stored in the form of starch which in future yields fruits.
The process of photosynthesis is commonly written as: 6CO<sub></sub>2 + 6H<sub>2</sub>O → C<sub>6</sub>H<sub>12</sub>O<sub>6</sub> + 6O<sub>2</sub>. This means that the reactants, six carbon dioxide molecules and six water molecules, are converted by light energy captured by chlorophyll (implied by the arrow) into a sugar molecule and six oxygen molecules, the products.