By definition, photosynthesis is a process by which photoautotrophs convert the energy derived from the Sun into usable chemical energy. Light, water, chlorophyll, and carbon dioxide are the basic requirements for this process.
Step 1
Carbon dioxide in the atmosphere enters the plant leaf through stomata, i.e., minute epidermal pores in the leaves and stem of plants which facilitate the transfer of various gases and water vapor.
Step 2
Water enters the leaves, primarily through the roots. These roots are especially designed to draw the ground water and transport it to the leaves through the stem.
Step 3
As sunlight falls on the leaf surface, the chlorophyll, i.e., the green pigment present in the plant leaf, traps the energy in it. Interestingly, the green color of the leaf is also attributed to presence of chlorophyll.
Step 4
Then hydrogen and oxygen are produced by converting water using the energy derived from the Sun. Hydrogen is combined with carbon dioxide in order to make food for the plant, while oxygen is released through the stomata. Similarly, even algae and bacteria use carbon dioxide and hydrogen to prepare food, while oxygen is let out as a waste product.
