- Photosynthesis is the process that plants use to create food from sunlight, water, and carbon dioxide. The byproduct of this process is oxygen, created when oxygen molecules are split from the hydrogen molecules in water. In order to successfully complete the process of photosynthesis, the plant must have the correct amount of water and be able to bring in carbon dioxide and release oxygen. Both of these functions are facilitated by the stomata.
- Surrounding the stomata are cells called guard cells, which control the opening and closing of the stomata. When the plant needs to close the stomata, the guard cells are filled with water, which swells them until the stomata are sealed shut. When the plant is ready to open the stomata, the guard cells are drained, which creates an opening.
- Transpiration occurs when plants release water vapor through the stomata, which results in additional water being pulled up through the stem and circulated through the plant for use in photosynthesis. The structure of the stomata allows the plant to open and close these openings based on the water needs of the plant. When there is little water, the stomata remain closed in order to conserve moisture.
- Stomata are also used in the exchange of carbon dioxide for oxygen. Carbon dioxide from the atmosphere is drawn in through the stomata, and oxygen is released as it is produced through photosynthesis. When the stomata have to be closed due to water shortages, photosynthesis cannot occur due to a lack of carbon dioxide.
- The unique structure of the stomata make the plant more efficient, and better able to cope during different environmental conditions. Less advanced plants, such as the liverwort, do not have stomata. These plants have continuously open pores, and therefore can only survive in extremely wet environments. The use of stomata, however, allows plants to survive in many different types of climates.
